Yes 3 Pilot Head CSI.

NUTZ4SAND sent me his 3 Pilot heads for evaluation, all 3 are Honda heads that have been modified, 2 are modified by PCP and one by "ATV" I assume ATV Racing?

The unpainted head on the left is PCP the middle ATV and the right PCP painted.

Attached to the heads was the solder he crushed to check squish on his Engine

PCP unpainted was .046 Squish angle 15 degrees
ATV .040 Squish angle 15 degrees
PCP painted .043 Squish angle 17 degrees

ATVR fail

Just for the heck of it I dropped each one on my wifes Pilot to check the static compression, then I checked how many cc's each head was..

PCP bare 215 psi 40cc
ATV 185 psi 45cc
PCP painted 215 psi 40cc

The PCP painted head (in the picture below) and the PCP bare head BOTH have had the top side of the head machined where the spark plug makes contact when you tighten it I can only assume this was done to repair wear damage where the spark plug gasket seats? See how it sticks into the combustion chamber, a shim needs used when using this head to keep the plug back perhaps 2 gaskets can be used, I know they sell spark plug shims but I don't know where you can get them.

The PCP painted head has a double squish angle, not sure whats up with that perhaps its some secret squirrel stuff I never read about.

The arrows point to where the angle changes, hard to get this pic.

So NUTZ4SAND what exactly is it you want me to do, I assume you want at least ONE head machined for pump gas, I never ran less than 47cc dome in my Pilots I never seen a need to, I am not sure what PCP or ATV had in mind when they setup these heads, this is why most people will not touch others work, I must say I am starting to understand why, all 3 heads have either PCP or ATV carved onto the head, its not fair for me to modify their work and they take the credit or the blame for how it turns out after I modify them, we need a solution here for the heads I modify, fill in the name with JB weld or maybe add "hoser" and a number below the name so who ever ends up with the head in the future knows it was not just ATV that worked on it.

Might I suggest I take one of the heads (your choice) and open up the bowl to 47cc and send it back to you for testing, it would be setup for use with a stock FULL 3 layer head gasket and pump gas, a minimum of 91 octane with 93 octane preferable. I would pick the PCP bare head because you have two heads the same cc the other one is the PCP painted head and it has the 2 angle squish band. the ATV head is 45cc you might keep that one for when you feel like running race gas...

I bet all 3 heads had REAL good throttle response and killer bottom end power with compression that high, when I add volume to the head and lower the compression some of this will go away, depending on how you had it tuned and how you tune my modified head you might not even notice the difference, I bet the only difference you will notice will be the idle will have to be turned up some.

I guess I am a little glad to see you got the 215 on two of them anyways. Basically pick the one YOU think is best to work with to save and open that puppy up. Heck you mentioned 47cc. Do that or even a couple more if possible. I would rather give up a tiny bit of power and have it run like a Honda should than near the edge of meltdown! I have no issues with 93 octane gas for 3.00 a gallon ( or 3.30 depending on the day... : / ) But I do not wish to have to buy 7.00 a gallon race gas if I could help. Lookign for fun mostly in this machine. Not a maxx racer. Please cut one as you see fit to make it as close to reliable as it can be! In a perfect world I would want proper squish and 155 to 160 PSI max. Thanx Bill

My personal edit for afterthoughts--> I am just kind of thinking why you got such a PSI differance on the one head. My tests were never more than 10 psi differance and I checked them more than a few times. Does this mean anything to you??? Just thinking outloud as it is/were. I also never noticed the sparkplug issue. I will have to keep that in mind. Thanx Bill

As for whats wrote on the heads you can write "Corrected by" "Fixed by" or "Saved By" and Your name. Or Make a circle around the words there and draw a line through it (A typical ban sign) then write what you wish. Knock yourself out on that! Thanx Bill

I don't want to mock them, give or take credit away I just want it clear to anybody its been modified by more than one person, its only fair to them.

You can put what you think is appropriate on there. I am not sure about the ATV head as it was sitting on a cylinder I have with PMR (Port Majic Racing??) when I got the unit. The PCP heads were stock till I mailed all three heads and all three cylinders ( The one PRM cylinder and two stockers) and the motor (( Internal Combustion Engine ? )) out to him for a bottom end rebuild and a port job on the other two cylinders. What you see is what I got back (headwise). The ATV head was already modded. I do not know if he did anyhting more to it. The PCP heads were all his doing from stock units. Bill

When you sent your parts what type of port work or Engine build did you request, example play, full race or what does he offer?

When I sent the whole kaboodle to him I knew the one cylinder (The PMR one that came on the built machine) was ported quite a bit as the differance between it and the stockers was evident from any angle. I told him I wanted good strong play motor (( Internal Combustion Engine ? )) for trails and dunes that would run on pump gas. I also told him to tell me why he thought the PRM one and ATV head (that's what came on the machine when I bought it) went the first time and let me know if it was to modified. When he sent it back there was no communication (written or oral) that I would need to run any fancey race gas or anything. He took a lil longer then promised sending the Engine back (no biggie there) but then I had to email him and call a couple times a good bit later to get him to send the other cylinders and heads back to me.


Being that all did not come back TOGETHER he may have not checked anything for "proper matching" to the other parts and just did a bunch of modding. This is totally my speculation but I have no idea why he would make heads to crank 215 PSI if he was doing anything this side of an alcohol race motor (( Internal Combustion Engine ? )).....??? To me he went either way overboard or perhaps did not finish the job he started?

Do the heads look like he did any work (The PCP ones) compared to a stocker BESIDES cutting the gasket face down? I did not do any measuring to the stockers when I had them (Did not think I needed to) and do not have one to compare them to (obviously) Are those angles what a stock head would have? I just wonder now if he messed with the inner chambers of just cut the face? Bill

Listing in the same order as my first post here is what we have


PCP bare 215 psi 40cc NOW IS 170 PSI at 47cc
ATV 185 psi 45cc NOW IS 180 PSI at 46cc
PCP painted 215 psi 40cc NOW IS 160 PSI at 49cc

All were taken using the stock HONDA FULL head gasket, you can use a THICKER head gasket but NOT thiner!!!!

Keep in mind depending on a few different things like your compression tester calibration being different, the height of your exhaust port compared to mine, size of carb, filter resistance type of reeds etc. the pressures most likely will be different, don't bolt these on and ask why it reads different hehe, the static compression is like the cc's it for comparison.

This what your looking for?

I would be tickled with 16o PSI once on my machine. I understand all the little differances that could make this machine get more or less that your wifes. The higher ones ( 170 PSI and 180PSI do gimma a lil heebee jeebies with my past issues.) Once I recheck squish on them I may see about gaskets from Cometic. They can make them a lil thicker depending on what readings I get. Is there any chance that more could be taken from the higher PSI ones or have you went with what you feel is max? Thanx X10 Bill

I can remove more material from the other 2 if you feel the need to have all 3 at 160-165 lbs, I thought you might want to try them first? You want me to send the 160 psi one and hold the other two until you test?

The 180 PSI one might be a good canidate to pull a little more out of it. If its not to much to do. The 170 PSI one should be fine even If I have to boost the "tane" a little. But the highest one still scares me at that PSI. I wish I knew what it would be on mine but only one way to tell that eh? Thanx Bill

Hold up for now If you have not already started. We can try the one head (the 160 PSI one) like you said and see where we are at from there. The others? We will see. If you see this before you start more on the 180 PSI one hold up for now. If not then its still all good. Thanx Bill

Your heads are completed per your last request by email, the heads are as follows.

PCP bare 215 psi 40cc NOW IS 170 PSI at 47cc
ATV 185 psi 45cc NOW IS 160 PSI at 49cc
PCP painted 215 psi 40cc NOW IS 160 PSI at 49cc

All 3 heads were lapped flat you will see the gasket area is gray once you get them where they were lapped.

I washed the heads pretty good but as with all parts you will want to wash them again real good before use.

You can see in the pics I put 'hoser' on the heads one I put PilotOdyssey.com I didnt like the way it came out so I didnt do the others, I am no engraver lol

I will include a USED stock Honda head gasket you can use for mocking up and checking compression what ever before use if you like.

Heads will be shipped today.

They look good and I will post what I get for compression and the "squishes". I have a compression checker that's not major name brand but IT DOES have the valve right at the fittting that goes in the sparkplug. I have been thinking about buying a higher quality one. Or at least comparing this to a known good gauge at say 100 PSI and see if mines even close. I would like to thank you now and all I need to do is figure out a way to make this up to yah. IF you got a bright idea on that drop me a line. THANK YOU Bill

Got the heads back today. They do look good. I checked each one on my machine (but on just the one cylinder.) for comparissons sake. Keep in mind that my piston is NEW (never seen fire in the cylinder and rings are not seated.) This was on an old used stock gasket as well.

PCP bare 47cc head 157 PSI Squish measured .042 (clutch side) and .044 (1.07 and 1.12 metric)

PCP painted 49cc head 150 PSI Squish measured .042 on each side. (1.07 metric)

ATV head 49cc head 150 PSI Squish measured .040 on each side. (1.02 Metric)

I am going to finish assembling the unit tonight and break in run it tommorrow. I am soooooo hoping the head and carb issues are cured and I can really get some time behind the wheel before Oct 31st (Silver Lake Sand Dunes closes then for the winter if you did not know.)

Once again Thank you Hoser. I owe yah. Thanx Bill

Any updates, test runs?

I have the PCP bare head on it. I finally got a chance to fire it up yesterday (I wanted to take it to the dunes this weekend but will be doing so today it looks like.) As I cleaned the carb after adding my new power jet kit I discovered the Pilot air screw was missing the oring and the little washer that rests against the oring. I made a washer to fit but had to go to four different places before I found such a special o-ring to fit down in there. I do not think it even had it when I tore it apart butI could have missed it and not seen it fly out when using compressed air to assure clean passages. Its got it now and that what matters. I ran it yesterday without the seat and safety harness out of it so I could get to things and see better. It was just the initial heat the piston cycle. After that I let it completely cool and the compression test (throttle jacked wide open) revealed a solid 160 PSI. I ran out of gas so I am gettign ready to go now and get some more for it. SO far it seems good and the plug looks better than it ever did before so I am hoping.

One thing that may be normal or not. I have a large clear fuel filter going to the carb (see pic below) When the thing is running it seems the fuel pump can barely keep any fuel in it at all. Easily less than a 1/3rd full all the time. (My lean out condtion??) The only time the filter gains volume in it is when the motor (( Internal Combustion Engine ? )) is shut off then the trickle down effect fills it some. I would think the fuel pump would fill it easy as the overflow tube up top is (I thought anyways) there to take excess fuel back to the tank. But it should be filled almost up to the return tube?? I checked the fuel pump once before and am going to recheck it according to the book. Hoser if you have a better way to test these pumps I would be willing to test it that way too. Bear in mind that I of course did not rev the motor (( Internal Combustion Engine ? )) to much (nearly none. Just a couple blips here and there to vary Engine speed a little. Very little idling. Usually above idle a little) That said the pump might pump a lil more with more rpms more the carbs gonna go thru a lot more. (I am not convinced of this as the pulses will be faster but not as "pronounced" thus giving less input to the pumps diaphram? Or am I wrong about this?) I was worried as I have heard that the paper filter would not allow the gas through it with gravity feed but the first fuel into it went right thru till the carb got a drink and the Engine fired. Bill

Oh yeah. One other thing that delayed me a little was I had to get a reed spacer and install it. (Yah I retested for vacuum and positive pressure in the crank after I changed it) When I was modding the carb for the power jet kit I noticed the bottom of the FRONT of float bowl when the choke circuit is was wearing from rubbing on the starter. It was not a problem with the stock manifold but with the new larger CR250 manifold that Hoser guided me to for easier fitting of the larger 41mm carb. The new manifold is a straight shot into the reed cage but it does hold the carb a little closer to the cylinder and thus the carbs fuel bowl was bumping the starter with motor (( Internal Combustion Engine ? )) vibration. There was enough wear that had the motor (( Internal Combustion Engine ? )) not had another issue that cause me to go into it again it might have worn through with a couple hours running. Thanx Bill

I have near two tanks thru the machine now and it seesm to be running fine as frogs hair. I still am not going for broke with the throttle but have tapped it a couple times late in the second tank but not long enoguh to get the rpms way up. The coolants hottest temp so far has been 197.7 (Digital temp with max and min readings) And the cooling fan does seem to be on most of the time when I come to a stop but it shuts off within 30 second usually. I finally got home tonight after some dune fun ( no one there makes for dam smooth dunes!!! ) The reason I say finally is my dune truck decided tonight was its last night to go duning as the motors head or headgaskets gave way.

The Carb adjustments (the things I fixed like improper jets) The Power Jet kit I installed is awesome. Its not as nice as dial a jet with a knob (But it is 1/3rd the price. And its fits any carb but was MADE to fit the Mikuni Proseries. So installing it was falling off a log easy.) but all you have to do is undo one screw on the top of the back of the carb and then unscrew the jet there. Lifting the brass jet out is tricky so you need a fine little wire with a tiny hook bend to reach in and lift it out once unscrewed. I started out a lil rich (on purpose) It ran great in the midrange but the top end burbled a little. Just for laughs I put a bigger jet in the power jet and it flat out would not rev well once past half throttle. The power jet kicks in there and supplys the extra fuel needed. Once I went one size leaner than I started with the thing ran smooth from the bottom to the top. It might be me but it does not have the hit it used to but it seems to actually have more torque low and pull better thru the range. Before it seemed to smack you harder after a little windup. Might have been the jetting issues. It will walk up Test Hill at Silver Lake at about half throttle with out to much trouble and not a big run. (that's with my 270 pound ash in it!) The fuel pump IS keeping the fuel filter full once it gets fuel in it so that's good. The compression test tonight showed a solid 160 PSI.(throttle wide open) I tried to get a good spark plug pick but my camera was not having it to well and I gave up after ten and posted that one below. Once again Thanx hoser for all the help and wish me luck with it in the future. Bill

Why are you running the second filter?

I run the stock Honda filter only and never find any dirt in my carb, I have found fine rust and sand in the filter but nothing ever in the carb.

Try to take more plug pics in the sun when you get a chance we need some profile pics too.

My tank is clean and I have a new Honda filter in the stock location. The large CLEAR see thru filter allows me to see that there IS gas going to the carb and being that it holds a small volume of fuel it acts like a tiny pressure boost due to the extra fuel weight (Like a water tower for a town.) Being that this carb is so much larger than stock and the motor (( Internal Combustion Engine ? )) mods I figured it could not hurt to have that little extra there just in case. So far it has been a good reassurance for me that fuel is always there. I consider it a great easy thing for the few bucks it cost to do. I will have to see about pics later today. I am going here to look at a new truck : / in the next little bit and the person who is helping me has to work later so I gots to go now. Thanx Bill

I am not sure how to do two pics a post sooo.