The Honda PCX / Forza / ADV150 / SH Forums

This guide describes how to install a big bore kit on your PCX. I would like users to refrain discussing whether or not performance modifications are worthwhile to avoid doing so here; any posts of that nature will be moved to this thread: http://hondapcx.org/viewtopic.php?f=9&t=626

As with any performance mod, your results will vary with your bike. The kit I installed on my PCX is specific to the 2011 Honda PCX 125, and will not fit the eSP model, the 150, or the new 150s. I have much more sustained power uphills, and about an extra 10mph top end after changing out my transmission gearing (How-To for changing transmission gearing is coming soon).

The process for installing the big bore kit is not easy or quick, and assumes that you have already:
1. Completed the How-To: Completely Dismantle A PCX
2. Completed the How-To: Remove the Engine from a Honda PCX
3. Procured a big bore kit and all needed consumables
4. Mentally prepared yourself for potentially destroying your bike if you mess up this procedure

Just like with the engine removal how-to, beer helps.


In addition to the tools used in the previous how-tos to get to this point, I used:
- Metric allen wrench set
- Small pick (moving O-Rings, using circlips)
- Feeler gauge
- Hammer drill (FUCKING EVIL OVERTIGHTENED SCREWS -- you might not need this)

Honda recommends you use a silly $100 cam chain tensioner. I didn't. I removed the tensioner and allowed it to fully untension, then retensioned it and reinstalled it tensioned. It's still fine 2k miles later. More on that later.


You'll also need the following consumables:
- Coolant (You must drain and refill)
- Oil (You should change the oil after the first mile, then refollow new engine breakin procedures and maintenance schedules, including another oil change at 600 miles, then every 5k miles. You do not actually have to drain the oil during the procedure)
- Rags (for cleaning things, clean lint-free ones to stick in any engine orifices if you need to walk away from the project)
- Carb cleaner (Your head will likely have carbon buildup, you should clean that before installing it)
- Sealing compound for the valve cover gasket around the water pump


Here's the parts we'll be installing today:

From left to right: piston rings and pin, cylinder, camshaft, gaskets, fuel injector (bottom right). The gear in the top-right will be installed in another tutorial (How-To: Upgrade Transmission Gearing).

A close-up of the cylinder. This is a Takegawa kit, and seems higher quality than the stock Honda components. Again, note that this kit is DIFFERENT than the one for the 150s and 125 eSP, because the cylinder and head is different for those revisions. This kit will ONLY work on the original 2011 Honda PCX revision 1.

A close-up of the camshaft (I still need to install mine, more on that later):

A close-up of the injector. Mine was branded as "MADMAX," but it's a OEM honda part from another bike:

You should be starting with your engine off the bike. I had Freedog muscle the engine onto a toolbox (he's built like a bear). The assembly probably weighs 100lbs, which I can lift, but would rather not. If you're puny like me, have a friend around to help.

If you haven't already, first start by draining the coolant. The drain plug is in the bottom-middle of the radiator. There will be a bit of fluid left in the piping, so I grabbed my coffee mug, undid the clamps, and drained the fluid in the tubes out.

With that out of the way, undo the radiator shroud then the radiator to be able to check if the engine is at top dead center. If I'm remembering correctly, the shroud had 3 bolts and so did the radiator.

You can see the radiator fan. It's directly bolted to the crankshaft, so spinning the fan pushes or pulls the piston accordingly, turning over the engine.

Looking closer, you can see an arrow on the left and a notch. Spin the fan until the notch lines up with the arrow.

At this point, the piston is in top dead center, but you need to make sure the valves are fully closed. To check that, remove the valve cover. Start by popping off the hose on the top, then remove the 3 bolts.

Wiggle the rocker arms on top of the valve springs. If they are solid and don't move, you must rotate the fan another 360 degrees because the engine is on the wrong part of the stroke. Rotate the fan around and check again. The rocker arms should have a bit of wiggle. Again, YOU MUST HAVE SOME WIGGLE. Seriously, double-check. If you don't get this step right, your engine may meet your piston during disassembly, which would basically be like setting off a small grenade in there.

When you're triple sure your engine is at top dead center (did you check again? WIGGLE THAT ARM!), remove the water pump and the hose with it (5 or 6 bolts total for the assembly):

The top comes off first...

Then slide the pump base off the camshaft. It takes a good tug to get it undone.

You can now see the side of the cam chain gear.

Looking closely, it should look just like this in top dead center. Remember that -- it'll be important later for when we have to put the cam chain on afterwards.

We need to get the FI system off of the cylinder next. Unbolt the two bolts on either side of the injector and pull the whole intake system (injection, throttle body, and air filtering system) back up and away from the cylinder:

On my PCX, there was a spacer with an o-ring, and an o-ring. Make sure you don't lose either.

The spacer goes o-ring side down towards the cylinder:

And the o-ring stayed attached to the intake setup, as shown below:

Speaking of the intake system, it's time to change the injector. When you upgrade to a big bore kit, the FI system can only compensate so much with the stock injector. Upgrading to one with bigger jets allows more fuel in, allowing the engine to use that extra displacement for more power, and preventing a lean condition from having too little fuel combusting in the chamber.

The injector is held on by the two blue bolts. Remove them.

The bottom side of the injector, removed.

Pull the injector out of its mount, click the new one in, and reinstall. Make sure the new one has the same thick sealing o-ring as the original. Reinstall the injector in the intake system, but leave the intake detached.

The ignition system is mounted to the cylinder, remove that next. It's on the left side of the bike. Remove the plug off the sparkplug, and pull the ignition coil off with the two bolts securing it:

Remove the mounting plate for it too:

With the intake and everything else out of the way, remove the cam chain tensioner. It's on the top of the cylinder.

Honda advises removing the EVIL BASTARD SCREW on the middle of the cam chain, then using their $100 tensioner (basically a tiny clamp) to keep it locked wherever it was before. You should totally do that. I didn't and it turned out fine. $100 for an ounce of metal is insane, and I refuse to pay for it. Even if I had wanted to use the tool, the tensioner tightener is underneath that philips head screw in the middle. At least on my bike, that screw was tightened by a pissed off gorilla on steroids. I couldn't get it off while it was still in the engine. I ended up clamping the tensioner to my bench and removed the screw with a hammer drill and a bit. You might get lucky and be able to just unscrew it. Anyways, I'll get to that when we reinstall it. For now, just remove the two bolts and pull the tensioner out.

Note in the second picture how the tensioner is fully extended. When it was in the bike, the piston looking thingy on the left was way more retracted into the housing. The Honda tensioner part that costs $100 (which is ludicrous) would hold it in place. Did I mention it's ridiculous that they want $100 for basically a tiny clamp?

I digress. Set the tensioner and its gasket aside, you'll worry about it again during reassembly.

Now that the cam chain is untensioned, remove the camshaft gear, behind where the water pump was, by removing the two allen screws.

It's difficult to remove, and even harder to reinstall later. Be patient, and don't force it.

The cam chain is secured in the bottom end, and you REALLY don't want to lose it down there. Put a zip tie or some string or something around it, so you can pull it back out of the bottom end if it somehow falls in.

It's time to remove the head. Unbolt the two long bolts that are below the water pump, holding the cylinder to the block.

Then remove the four nuts at the end of the studs that hold the rest of the cylinder and head in place:

Sliiiiiiiiiide the whole top end off. You might have to give it a few good tugs to get it started:

The piston will just flop down, and the chain will slowly sliiide through:

The old piston side by side with the new one. Phew, lots of carbon over the last 10k miles:

...To be continued.

how to maddiedog.

Yeah that cam tensioner tool is B.S. after you get that Phillips head bolt out a simple small flat screwdriver works just fine for tensioning it back together.

WOW!! I'm not sure that I would have the "cojones" to do this, but it's an EXCELLENT tutorial and, like the one meant to completely dismanthe the PCX, absolutely brilliant!!!! Of course, I'm subscribing...

That's very good How-to .
Have you done this before ? a big NO for me

I haven't forgotten about this how-to, just been super busy! I'll get to it eventually.

No problem, and thank you very much for the very useful information!

It's been a long time and still no conclusion to this tutorial? Did the project self-destruct? or what?

flyingzonker wrote:It's been a long time and still no conclusion to this tutorial? Did the project self-destruct? or what?

No, project is still good. The kit has 4k miles on it and runs like a bat out of hell.

I haven't had time to finish -- I will one day, I promise.

I wonder - are you a self-taught home mechanic or a mechanic by trade? Simple tasks like the oil change, removing the rear PCX wheel I would have a go at, but this - this is a whole different leauge

Self-taught. No one in my family is mechanically inclined at all.

I'm a Systems Engineer doing IT deployments for a living, and was just an IT guy before that. So... Computers all day, every day. I get to flip bits all over the place when I'm designing a network, but never can put my hands on the data. Mechanical tasks are fun because they're tactile; I get to get my hands dirty.

I'm on vacation, so that means I finally have time to continue this beast of a how-to!

At this point, you just took your head off the engine. You can look up into the head, the intake valve is the big one and the exhaust is the small one. After the combustion cycle, the hot gas has expanded and is under pressure, shooting the piston down. The exhaust valve opens, and the gas keeps expanding out into the exhaust system. Here's a view inside the cylinder looking up towards the head. The spark plug is the thing in the top center, exhaust valve on left, and intake valve on right. The plastic doohickey that hangs off the left side and came out from the depths of the lower end is the cam chain guide.

Take the head and cylinder over to your lab bench, where you have a nice clean pad to work on. Gently separate the head from the cylinder. There are a couple of little connection studs, make sure they stay with the head.

Below is the head, with the cylinder removed. For this kit, the cylinder gets replaced, but the head gets reused. Some kits replace the head too, and I kinda wish this one did as well. More on that later. You can see the valves closer up in this picture. The big slot at the top left is where the cam chain goes. In case I haven't mentioned it yet, the cam chain drives the camshaft, which opens and closes the valves at the right timings to get a good explosion contained to propel the bike forwards. The 8 oval-shaped channels around the cylinder area are the channels for coolant to flow. Everything here is dirty, and you can see there's coolant and bits of gasket on the head. ALL that needs to be clean and smooth to get good compression with the new gasket, so it all gets cleaned up.

Polish that head! Getting cleaner...

Shiny enough.

Check the new gasket for fitment. Mine blocks some coolant passages partly. This was my concern, and the reason I said I wished the kit came with a new head. It's fine 3k miles later at this point, so I'm confident this is good enough. Note the two connection stud thingies in the top right and bottom left. These sometimes come off with the cylinder, so make sure they end up with the head.

The next part has to do with changing the camshaft. You can skip all this if you're not doing a cam. I ended up not putting my camshaft in, but might put it in next time I do a valve check.


-------------- CAMSHAFT--------------

Flip the head so the valve side is down. Make sure the cam has the dot side up, or you can't wiggle it out. Here's what dot side up looks like on the side of the head (look at the dot at the top middle of the inner part of the camshaft at the middle of the pic).

Flip that head over again, and remove the two retaining bolts for the water pump collar:

Remove the bolt securing the camshaft. You can see the two cams and cam rollers at the top of this pic. The two rollers should look perfectly smooth, with no grooves. The cam chain rotates the cam shaft. The lobes on the camshaft roll, with the elevation changes opening and closing the valves in the engine at appropriate times so that air gets in, compresses, stays in to go boom, goes out, and then new air comes in. An aftermarket cam increases the time the valves stay open, sometimes having the exhaust and intake valve open for just a bit of time so that more air gets sucked in. More air = more boom! The caveat here is, engines like the PCX's are interference engines. They have 4 strokes (hence the name), which correspond to the 4 appropriate aforementioned times. If the valves stay open too long, they will actually hit the piston, turning your engine into an expensive paperweight. Anyways, I'm rambling...

You'll also have to detach the rocker arms that go to the valves, so loosen these two bolts too.

And remove the two bolts the arms pivot on:

Wiggle that camshaft out!

This pic shows an aftermarket cam next to the stock, respectively. I chose to leave mine out for now to see how the bore kit performs on its own, and may eventually add the aftermarket. Note the stock one, at the end of the camshaft, has a special spring-loaded lobe. This lobe rotates the cam when the engine stops to be in the optimal position to start immediately, and I think is called a decompression lobe. I'd say it's fairly essential to a PCX with idle stop, but it just means my PCX would be slightly harder to start. I left it off regardless. PCXdemon, our performance guru here, has assured me that the aftermarket cam would be fine without the spring-loaded lobe (you can mount it on there if you have a bearing puller, a press, and balls of steel that aren't afraid of accidentally destroying the camshaft bearings).

Reassemble the head in reverse order.

-------------- PICK UP HERE IF YOU'RE NOT DOING THE CAMSHAFT--------------

With the gasket in place, check fitment of the cylinder:

Remove the big black coolant hose from the side of the old cylinder. I totally forgot to take pics of that. It's just a basic clamp. The cam chain guide should just fall out too, take that out also.

Remove the coolant plug from the side of the old cylinder. Make sure you get the sealing washer:

Install the plug and the coolant hose on the new cylinder.

Place the cam chain guide in place:

At this point, you can place the cylinder on the head, carefully. Make sure the gasket sits flush, no debris is in the way, and that it is aligned perfectly. Secure the cylinder to the head using the cylinder head bolts. I did not see a torque spec, so be sane with your torque but make it good and tight.


Go back to the old cylinder and remove the two connection stud thingies:

And install those stud thingies in the cylinder. With the cylinder on and the cam chain guide in place, everything should look just like this:

Now time to go swap your piston!

Go back over to your engine, and get a pick in the hole on the side of the cylinder to pry out the circlips. You have to remove the circlips to get the piston's pin out to get the piston off the conrod. The circlips are a bitch to remove, good luck!

Yup, still picking away. Get a beer or two and walk away if you get frustrated.

ALMOST!!!

Now, GENTLY push out the piston pin:

The old piston, removed:

Now, we prep and attach the new piston.

At this point, some people gap the rings on the new piston. Google that if you want to, or check page 10-8 of the PCX Service Manual (2011). The kit was precisely to spec, so I did not have to gap mine.

The rings have to be installed in a very specific order, as shown in the close-up below, with the rings gaps offset as below:

The Honda manual is worth 1000 words:

Rings installed on the new piston. I made sure me, the rings, and the piston were all nice and oily to make sure no raw metal rubbed ever:

Before I install, one last look at the new piston vs old:

Slide the new piston on, and slide the new piston pin in:

Attach the terrible circlips. You should use new ones included in the kit. Make sure the gap does NOT line up with the cutout; rotate it until the gap is away from it.

Piston on! Note how I've carefully secured the cam chain so it didn't get dirty or fall into the lower end while I was working...

Put the gasket for the lower end on, and make sure it is sitting flush with no debris or anything blocking a good seal. Check the lower end to make sure it is clean and ready for a new gasket, cleaning off where needed.


Time to put the top end back on. Get a friend, you'll need him or her to guide the cam chain through as you gently put the cylinder down over the piston. Make sure to oil the inside of the cylinder before cramming the piston in.

Note that the cam chain tensioner is facing up (the round opening at the top of the cylinder).

You will have to carefully wiggle the piston and tighten the rings so the piston fits in. This is normal, take time and finesse, and has to be done right. You want all your rings to stay in place, both on their slots on the piston and in their 120 degree offset laterally around the piston. Note the 3rd hand using the zip tie around the cam chain to gently pull it through. You want to make sure during this step that the cam chain guide is sliding into the right spot in the lower end too, look at where it's going and make sure it looks right.

Finessing the piston into place:

And it should just sliiiiiide on down.

Tighten the 4 bolts on the head back up to spec, installing the washers first. Honda calls for 20 ft/lbs of torque, but indicates that you should oil the threads first. Keep in mind oiled threads take less torque to tighten the same amount, so use caution and do not overtighten or undertighten.

To be continued...

Now that the head is on, we need to reconnect the top end of the motor so the valves can function and let the engine breathe. The valves are closed without the camchain attached, as they were when we first made sure they were way back during disassembly when the engine was placed at top dead center. Double check that the engine is still at top dead center. The notch should still be lined up with the arrow:

Whilst doing your best impression of a gynecologist given the extremely tight space, snake the cam chain gear back into the head, get the chain back on, and resecure the gear to the cam, ensuring the line on the cam is vertical and in its idle position. It should look like this when secured:

I should note here, it's REALLY hard to properly get the cam chain in there and on the gear, then secure. It will take a lot of delicate finessing to get in place. Be patient, and take your time -- you want to get this right or your engine won't run or will run poorly or will just blow up if the timing is too far off.

When the cam chain is on and secure, check the radiator fan again. The notches should still be in perfect alignment when the cam is in perfect alignment as pictured above. If it's not, you've put the cam chain on the wrong tooth of the gear. Take the chain off, rotate the gear a tooth, and try again. The lower end and upper end should both look like the previous two photos.

Before we rotate the engine over, since the engine is at top-dead-center, triple check your cam isn't upside down by wiggling the rocker arms like you would to check for top dead center during a valve adjustment.

While I was in there, I checked my valve specs and recommend you do the same. Mine were in-spec, as they have been ever since the first service. Note that ticking after this process is done usually indicates your valve cover gasket isn't sealing well or you screwed up the valve adjustment.

Now, to quadruple-check, rotate the radiator fan (recall it is attached to the crankshaft directly) 360 degrees. Nothing should bind, but the engine may put a bit of resistance from compression. Keep going another 360 degrees for two full rotations. Nothing should bind, and your engine should be back at top-dead-center. Check your cam and rocker arms and fan alignment one last time, then move on.

The cam chain at this point may be a bit slack, because the cam chain tensioner is not attached. That's the doohickey that goes on the hole on the top of the cylinder that looks like this:

Ok, so time to rant on this... The cam chain tensioner is just that -- it tensions the cam chain. Behind that hole on the top of the cylinder is the upper cam chain guide. The cam chain tensioner is a fancy wound spring that puts constant outwards pressure through the springs, but is unable to retract, ensuring consistent tension on the chain. That means your tensioner right now is locked fully outwards. If you press on the part to the left, nothing happens! Madness! The stock Honda tensioner tool, which is a $100 screw and nut, are designed to hold the tensioner in exactly the position it was in when removed to allow easy reassembly. Well, $100 is ludicrous for a tool that you'll use once. Remember this picture?




In it, you can see the cap over the tensioning screw. It will be factory overtightened. Remove the cap in the middle of the top of the cam chain tensioner. You may have to use an impact gun (I'm not kidding).

At this point, you can see the middle of the tensioner, including a tiny little winding screw in the middle. The tensioner uses a helical spring, which you can rewind to retract the tensioner! WOO! Ok, I'm getting too excited (but seriously, I figured this crap out and it saved me $100 on the stupid Honda tool, and might save you that too). Stick your tiny screwdriver in there, and tighten it. The tensioner will wind, and the rod holding the tension on the cam chain guide will retract, as you can see below:

Now, the only problem is, the SECOND you remove that screwdriver, the tensioner fully extends, ruining all your hard work. So either grow two extra arms, or find a friend. Whilst holding the tensioner in full tension, bring it over to the cylinder. Have your friend install the new gasket for the cam chain tensioner, and, still holding the tension, place it in place. KEEP HOLDING THE TENSION FULLY while your friend tightens the tensioner into place. The only thing the Honda tool is for is allowing you to solo this part. Tis silly.

Here's what it looks like, me holding tension like a boss and installing it in the PCX:

Once it's fully seated and tightened, slowly let the screwdriver unscrew as the tensioner seats. It shouldn't unscrew too far, it should only unscrew a bit. If it unscrews as much as it took to screw to retension, something is very wrong with your cam chain or tensioner.


Put the valve cover on, putting a dab of sealant at the corners of the water pump (the valve cover is prone to leaking there). Make sure you don't overtighten. The post-2011 PCXes have 4 valve cover screws, but this one only has 3, so if you mess one up, you're going to have a bad time. (as an aside, I accidentally broke one of the valve cover bolts on Mel's wife's PCX. It doesn't leak at all, so the 4th is important, but not needed, on the post-2011 PCXes).

Start connecting everything. Connect the electronics, throttle, and fill up coolant. Somewhere in there I also hooked up the radiator hoses to the new cylinder and everything else. Just reverse the reassembly. Make sure no connector goes unconnected.

Make sure you hook up the throttle cable right. I didn't, and nearly went for an involuntary ride around the neighborhood when it ROARED to life the first time.

Finally, bleed the coolant system or you'll get an overheat warning. You will have to rebleed after starting it the first time too. Here's the pages from the manual:

I should note that I had to bleed my coolant 3 times before all the air was gone, so don't go into full panic mode or drive far from home until you're 1000% sure your system is free of air.


Hook up your battery.


Wheel the PCX outside and, with your finger next to the kill switch in case of disaster or weird noises or mistakenly putting the bike's throttle cable at the wrong angle so it starts at full throttle (I'm in no way guilty of the last one), crank it up for the first time.

SHE'S ALIIIIIVE!!!! HAHAHAH!!

To check for any issues, take it for a couple of laps around the street before buttoning her back together. I advise wearing gear. I was a bit too enthusiastic to bother.

You're DONE! ...Well at least with the hard part. Put the rest of the bike together, and break it in using whatever method you think is most appropriate, but remember that extended full throttle on a new engine is bad for it. You should vary your throttle constantly.

I ran the bike for about 10 miles, changed the oil (it had some gasket and a bit of extremely fine metal glitter in it when I did), then ran another 500 miles before changing oil again. During those 10 miles, I had to rebleed the coolant system a few times, and the hot light came on once since the water pump was sucking air. After filling and refilling, all is 100% normal now.

After several thousand miles, I've noticed the kit gets oil dirtier faster than stock. Given I'm putting way more load on the PCX by using this kit with a gear up kit to cruise at 65mph or so for extended periods of time, I now do oil changes every 2500 miles as well. We'll see how long this kit lasts. I have gotten almost 3k miles out of it so far, and it's going strong still. About 50% of my riding is at 65mph when I'm commuting. I get about 85mpg now.


That concludes the longest, and most indepth how-to I've made. Just like any of the others on the site, if you have any questions, ask away, and if you found this site or how-to helpful, you can buy me a beer (probably more like diapers at this point) using the yellow DONATE button at the bottom of the page.

Hey Dave, "vacation" or "staycation". ... Either way, enjoy the time off.

Vacation! Just got home though. We spent a week in Ormond Beach, Florida.

Maddie,
Are you using the stock spark plugs after installing the kit, or Takegawa has recommended different heat range?
Have you checked them how they read since the installation?
Thanks
Tamas

Tamas, I used the stock plugs. The instructions don't mention any change in spark plug.

I didn't check them, but I got about 2k miles on the PCX before I sold it. It was running strong and quick when I sold it, so I don't think a plug change is needed.

good, have you used or installed any electronics ".. without rpm cut or injection change" or any such device?
just assembled the pieces that are in the photos?
What was the speed difference?
speed variator use the source?
valve springs changed?
sorry to be asking these questions all but wanted to buy a kit of these and on the site I see that one should change the electronica of the motorcycle and that for me is very expensive €€€€€ lol

hi hello .. this week I want to see if I'm the one next to mount my yuminashi kit on my pcx.
  is the complete 164cc kit, I'll also fit the final gear kit, the AFR (injection driver). as well as the gasoline injector of greater debit "tuning of model honda cbr 150cc" and inercia power boost .
I will try to insert here the references of the material, my pcx is a 125cc 2010 model of the jf28 engine.


38772-KWN-000A YUMINASHI FUEL-ADJUST CONTROLLER (5-PIN TO 5-PIN),

hi hello .. this week I want to see if I'm the one next to mount my yuminashi kit on my pcx.
  is the complete 164cc kit, I'll also fit the final gear kit, the AFR (injection driver). as well as the gasoline injector of greater debit "tuning of model honda cbr 150cc" and inertia power booster .
I will try to insert here the references of the material, my pcx is a 125cc 2010 model of the jf28 engine.


YUMINASHI FUEL-ADJUST CONTROLLER (5-PIN TO 5-PIN),38772-KWN-000A



44T FINAL GEAR SPROCKET SET, COMPLETE WITH SHAFT (PCX125 / SH125i)
23430-KWN-440



INERTIA POWER BOOSTER SET 15431-KWN-000



164CC LIGHT BORE FLAT DECK CYLINDER KIT (PCX125 V1) (FOR 125CC HEAD) 12103-KWN-600XA

Honda CBR 150 Keihin injector assy (Tuning CBR 125)16450-KPP-T01

Must get 150 head too ideally, it has bigger valves and ports. Deff more power and less chance from overheating. Also get yourself forza 35mm TB its awesome and its a straight fit. If you chose to keep 125 head, then you must do this...In the maddies photos above you will see a photo of a 125 head water ports with a 170 head gasket aligned on the head. You will also see that the 170 or for that matter 164cc cylinder ports from the head gasket don't align properly with 125 water ports. Do the same mock up and then use a black marker and colour in the metal on the 125 head water port that doesn't align any more. After that use either a dremel tool or a small file and process those ports biggest to align properly with the head gasket. Its very easy to do. After that you shouldn't have any more troubles with overheating. Also Install the plug Yuminashi specifies as that will actually run your motor few degrees cooler. I know as i have water temp meter and it clearly shows the difference.