Hey everyone, I decided that even though I had to re download every photo, it's important to me for this build record to be here since so much of the help I needed during the build came from here. I've written this from my own perspective with the intended audience being people who may not be Pilot purists.

This project began in July 2010. The project involved taking a 1989 Honda Pilot FL400r frame and installing a snowmobile Engine. The reason for me doing this is three fold. First is, I love Honda Pilots. I’ve always wanted to build a “super pilot” and this was my chance. Simply stated, it was the challenge of it. The second reason is pretty obvious, MORE POWER. A stock pilot comes with a single cylinder 400cc two stroke Engine. In stock form it puts out approx. 36HP. The Engine I chose for the swap is a Yamaha 500cc twin cylinder 2 stroke Engine which puts out approx 85HP. Not a bad increase. There are plenty of guys out there who go big with 800cc twin conversions but I didn’t feel I needed to go crazy and risk transmission failure. The final reason I did it was for reliability. The Honda Engine is good but it’s a one off in many ways. Many of the Engine components are no longer available so trying to fix it is often very difficult. The Yamaha Engine I used came from a 1996 VMax 500XT which is very common motor (( Internal Combustion Engine ? )) with easily accessible parts.

THE BUILD DAY ONE

Here is the basis of what I had to start with. I drove up to Conneticut to buy this beauty. It was in good shape besides obviously missing some key components like the Engine AND BODY. The underbody was pretty clean, not dented to death like a lot of Pilots from the northeast. The frame was straight, all in all I was pleased. Engine bay was a bit dirty but very good condition, no rust or dents that were serious







THE DONOR

As I mentioned, I chose to go with a 1996 Yamaha VMax 500XT for the sled donor. They are easy to find parts for and are well regarded as reliable engines. They are particularly good with low end torque compared with some of their 500cc competitors so I felt it would be a good donor. Another reason I chose it was that if I ever got tired with the 500cc’s I’ve read that the 600XT (a 600cc Twin) bolts right in to the 500cc chassis. This means that I could go find a cheap donor 600XT and drop in the motor (( Internal Combustion Engine ? )) and electronics with no more fab work, just some bolts and plug ins. Could be easily done in a weekend. The sled had a total of 2100 miles on it when I bought and according the owner it had a top end rebuild less than 100 miles earlier. I was very pleased when I bought it. It started right up with a cold Engine, idled nicely and overall looked like it was taken care of. The owner was shocked when told him I would be removing the Engine and trashing the rest of the sled. He reminded me that it was a perfectly nice sled, no reason to destroy it. It drove nicely up on to the trailer under its own power.





THE TEAR DOWN

We were very carful on the tear down not to damage anything as well as maintain all the sled parts possible. There are a few philosophies when it comes to a sled Engine transplant in a pilot. Many of those who came before me did a lot to meld the two entities together. They may have used a combination of sled CVT and Pilot. They also may have used a combination of sled wiring and the stock pilot wiring. I planned a different route. I wanted to go all sled the greatest extent I could. To that end, we were very careful in the tear down so as to keep every part in good working order so it could re used. We also checked everything as we removed it and replaced anything that was worn or broken.


















Once it was all torn down and everything was labeled and bagged I test fitted the Engine the pilot. It was a REALLY tight fit. This wouldn’t be simple. I was worried it would sit up too high. Some of these swaps require that in order to fit. I was hoping to avoid this if possible.



It’s important to address an additional philosophy on this build. I really wanted it done right with all the best people on it. Many guys who do these build take the attitude, if you want it done right, do it yourself. That is fantastic for them, I’m sure they are more than capable and I’m sure the work was great for that reason. I’ve got one problem with that, in my case, I KNOW I couldn’t do the best job. Almost everything that was done on this build was done by a individuals with expertise in that area. My problem is, I’m great at the planning and management, no so much on the technical stuff. :)

Back on track, one big hurdle was the wiring and electronics. For this part I hauled my pilot 2 hours out to Reading PA where a good friend of mine, Kenny agreed to help me wire it. Kenny is an ex-military mechanic who has more knowledge about wiring in his thumbs than I do in my entire head. The process took over 12 solid hours of work but we got all the main wiring done to make it run. Amazingly on the first pull, we got spark. I nearly knocked over Kenny (and a few empty beer bottles) with my dance of celebration. Kenny would have joined me in the dance but he informed me that Military men don’t dance in glee (nor do most other men, he added).













As mentioned above, I wanted to keep as much of the sled as possible. This extended to the CVT. The easy thing to do is use the sled primary and Pilot stock secondary. Other guys have done this effectively and it’s worked but I just didn’t feel like it would ever be tuned right unless the primary and secondary were matched. Other than the size difference (as seen below – The sled secondary is on the left) I was up against two major things. First is the shaft. Not surprisingly the stock Honda transmission shaft does not fit the sled secondary pulley. This would prove to be one of the largest issues with the build. The second issue was clearance. For Engine to fit and sit low in the frame it had to be pushed far to the left of the frame.







If the belt had to fit in alignment as the stock secondary it would have been WAY high and maybe not fit at all. My solution was to kill two birds with one stone. I decided to design a custom coupling which would fit over the stock pilot transmission shaft on one end and on the other go into the sled secondary. Simple sounding, complicated to work out. This part was way over my head so I decided I’d have it done professionally. I reached out to Wayne Hoez the owner of W.C.H. Welding in Philadelphia. He agreed to take on the job personally which I was great. He had done welding work on a Pilot a few years a back and was the welder on a motorcycle Engine swap on a Odyssey a year earlier. We decided we’d use the stock sled shaft and the stock pilot secondary pulley as donors for the coupling. The process took more hours than anyone could have expected. The work was redone and redone to get it true. Finally we took it to a the owner of a specially axle shop in Philadelphia who suggested that the only way to get it true was NOT to weld it but press it in and key it.














Now that the shaft was completed we could turn our focus to Engine mounts. The stock pilot Engine bolts directly to the pilot transmission. These two then create a solid package. The trans mounts to the rear frame with rubber mounts and the front of the Engine attaches to the frame with rubber mounts. Another priority of this project was to make it as “bolt in” as possible so that everything could be undone if need be. I also wanted an Engine which was easy to take in and out if necessary. Wayne built custom mounting brackets using the stock mounts from the sled Engine and the stock pilot transmission. He also built custom mounts using the engines mounts to attach to the stock mounting brackets on the Pilot frame. This plan allows it to bolt in on all sides, the Engine can be swapped with the same 500cc or its 600cc big brother, or the Engine can be removed completely and stock pilot Engine can be put back in. It worked out well. He used heavy 5/8th thick steel plate to make the mounts. They are super tough. I can’t image what could break them off. The Engine front mounts had to be made rubberized as well so as not to shake the pilot to pieces. Wayne got creative on this part. He went down to the local Auto store and found a sway bar bushing for a Monte Carlo sway bar which was the perfect size. He then bought a nut that size found on the Brooklyn Bridge (okay, maybe not quite that large) for the bushing to fit inside of. He finished it off with the perfect size bolt and BAMM, stock looking mounts.
















The next major undertaking was the exhaust. This was no small task given that there was bearly clearance behind the seat to begin with as seen here.





The issues didn’t exactly end with the tight space in the front. The bend which was required to go over the shock support bar didn’t match the bend of the exhaust quite right. In a perfect world a full custom exhaust would be built to go nicely over the bar. We opted for a high mount and a turn down on the exhaust into the stock silencer. The bend looks a little odd and may reduce power output bit but it was okay for our purposes.













Whit the exhaust run we had some odds and ends to clean up, the fuel tank was one of them. I went with a 4 gallon spun aluminum. On my previous pilot I had a similarly mounted 7 gallon tank. I found that when it was full it made the pilot a bit more top heavy. When it was empty is sloshed around a lot. For these reasons I wanted to go much smaller. Total ride time on one tank should still be in 4-5 hours so I figure I’ll be okay. The radiator was a point of much consideration for a few reasons. The first was the question of if a radiator designed to handle the heat from a 400cc single could handle a 500cc twin. We’ll be watching the temp gauge closely on that but it appears to be more than enough at this point. I had a override switch wired and a mounted on the dash so I could control when the fan will go on and off.





The odds and ends continue. I wanted to make sure that all the sled pieces had a welded bracket so they looked okay and were held in place as designed (no zip ties here). Some of these brackets included the coil, CDI (Capacitor Discharge Ignition), coolant/oil resivour, etc. I also had a nice loop welded in for the pull cord. It is located at the same place as the stock Pilot. These engines had an option of electric start which could be bought aftermarket or used. I’ve not done that yet but it would be nice addition since it currently is only pull start.













At this point I had pretty much everything mounted and ready to go so it was time to send it to its new expert, Mark, for a once over. Mark is a former motorcycle/atv dealership mechanic who now does mechanics as a side gig. He’s talented and knowledgeable. I sent it to him for a combination of things. First were the brakes. The fronts didn’t work at all and the rear caliber wasn’t even installed. Mark installed fresh pads in the front and found that he master cylinder was shot so we replaced that. They also needed a good cleaning and reconditioning. The rear was a big challenge. He invested 10 hours just in getting the rear brake back to good working condition. I didn’t want any compromises on the brakes given that the pilot would have more power. I needed to feel confident I’d be able to stop well. Mark made sure this would be the case. Mark also fabricated the throttle set up which was no small task. The sled requires two cables to be pulled (Oil injector and throttle). I wanted a reliable way for this to operate. Mark came up with a way to fab a 2 into 1 cable so we could use the stock thumb throttle from the pilot. I also had Mark give her a good once over and tasked him with getting the pilot started for the first time since the transplant began. Everything was done well by the professionals; Wayne and Kenny. The one part I did was run the lines (Fuel, oil, etc.). No big shocker here, he found a mistake. I switched two lines on the fuel pump so it wouldn’t run. Once Mark found this, it took him no time to fix it. Then the moment of truth… The pull start…. BAMM! Started right up, no issues. Mark sent me a video of it running I wanted to do a dance of excitement but pictured Kenny’s disapproving look at men dancing so I resisted the urge.

I brought it back home to install the plastics that a fellow member here, Hyde was so kind to sell me. Great guy, he gave me a more than fair deal and took care of the shippping. The plastics were really nice with two exceptions the first was the right rear fender had a chunk missing out of it (Hyde told me about this) the second was that foot tub that was originally on it had the front missing. Looks pretty bad but I'm not in the looks phase just yet. It will have to be dealt with at some point.









Next step was to get my intake set up. I went with a twin air intake set up using K&N filters. I combined these with intake tubes that ran directly to carbs. Currently the set is only hose clamp installed. When the pilot goes back to the welder I'll have him install brackets for them most likely.




With everything welded on, brakes all redone and the Pilot running it was time to tune. We took it to a property for its first shake down run. It started right up but barely ran (I’m not sure why I expected anything else). The jetting and clutching were all wrong. We also suspected the oil injection weren’t tuned right. It smoked like crazy and couldn’t get up to speed at all. It would take off okay but couldn’t get over half throttle.



Videos of it running, ignore talking. I was driving and not able to manage quality control.

Obviously not running well,



Once again, I decided that I couldn’t afford to not do this right so I reached out to an old friend, Josh Kurtz. Josh owns a shop which specializes in race tuning snowmobiles. He agreed that it was likely a combination of clutching and jetting. He was familiar with the Engine and knew exactly how to tune it. Today it's at Josh's shop and he's working on it. Once he's done, it's back to the welder to get my braket support welded on. Will update soon.

Nice write up...

Thanks KTM, I just realized how long that is, I wonder if anyone actually made it all the way through?

i read it all. im looking forward to running videos after its tuned!

I did, I found it very interesting how you did your powertrain to drivetrain. I had big ideas of changing mine around and may down the road. I'm thinking simplicity and relieablity for my project though...I'm looking at doing a 700Xx ATV motor (( Internal Combustion Engine ? ))...I originally was thinking XR650R motor (( Internal Combustion Engine ? )) but I would be giving up a reverse and the starter would be be hard to find. There is an e-start system built for the XR650R motor (( Internal Combustion Engine ? )) but they are rare and expensive aftermarket upgrade...so the next logical step was the 700Xx motor (( Internal Combustion Engine ? )) but the problem I have there is clutching...Rekluse from my understanding hasn't released an auto-clutch yet but when they do, I'll probably start looking for a 700Xx motor (( Internal Combustion Engine ? )) and start my build...I would have a Pilot with a 5 speed manual...YeHaaa! I would dump the Pilot CVT, mount a shaft with a short sprocket and go with a chain drive off the motor (( Internal Combustion Engine ? ))...The short shaft would connect up to the drive shafts via U-joint...

KTM,

Interesting idea, the 700xx would be nice addition. I'm curious though, why eliminate the pilot trans? They are pretty good, have limited slip, etc. If you keep the pilot trans you'd have way less headaches then you could use that 650 motor (( Internal Combustion Engine ? )), the pilot trans would provide reverse for you.

Your options are wide open, you could find a cheap engines out of any of the following chain drives

raptor 660 (37hp)
raptor 700
Canam/Bomb DS650 (42hp)
YFZ450 (41hp)
kfx450
ltz450
preditor 525 (that would be cool, it's a ktm Engine, 56hp at the crank),
TRX450r


Personally I'd stay away from the motorcycle/dirtbike engines. I've heard a few times that they often incur bottom end failure in buggy conversions since they aren't meant to take the strain the buggy weight/drivetrain puts on them. Any of the above quads would have pretty robust gears (stay away from 2001 Raptors unless they've had the trans upgrade done).

9:1 reduction. Bike/ATV Engine does not have enough output sprocket rpm to feed the pilot or Odyssey trans directly.

TRX700 is a nice set-up for us as the chain in inboard. That's what I wanted, but I'll never find one around here.

660 Raptor mo-tor (Its a Engine LOL) in my buddies buggy works great. Chain right to the rear axle.


The KLX650 in mine works good, but the jackshaft and dual chains to speed up the input to the Oddy tranny is a bit of a PITA.



My next build/incarnation will be Raptor powered. Plentiful and reasonable cost.

Just a quick update, it's been at the sled tuning shop for a few weeks now. He didn't start working on it yesterday. He found it to be super rich on the top end. he pulled off the air intakes and saw an improvement. He'll be pulling apart the carbs today for a good cleaning and rejetting. He's hooked up a tach so he can log his improvements. He does have a dyno but I don't know if he'll be using it.



Asaszn

I could use some input here...

Pilot is still at the sled tune shop. In the video I posted it was topping out around 4000 rpm it would fall on it's face if I pushed it harder. It was running 153.5 main jets plus the needles were shimmed. Turned out to be running super rich. He re jetted and then got it to top out around 4500RPM (he was using 140 or145 mains I believe.)

He then moved on to the clutch, he adjusted the spring on the driven and it jumped up to 5500 rpm. While in there he noticed that one of the weight rollers had a bad bushing. He figures this alone could improve it by 500 rpm. He fears that even with the adjustments he's planning to the drive clutch and the fixed bushing he will only gain 500 to 1000 rpm which will get us to 6000 to 6500 rpm. These things should top out at approx 8000 rpm so we're pretty far off the mark. If I recall, they make most of their HP in those last 2k RPM, is this correct?

He's beginning to fear that the problem could be the pipe. Frankly, I'm skeptical that a few inch long pipe would cause a 2000rpm difference given that he's played with Jetting and both clutches.

I'm wondering if there is something else going on here like a bad reed or something like that he may just not be checking????

Any thoughts on this?


EDIT: I found this chart for a 99 VMax 500 xt (i'm running a 1996 but I think they were the same Engine) it shows that the Engine produces 89HP at 7800 RPM HOWEVER it also shows that at 7000 it's making 80HP and at 7500 it's making 85HP. Does this mean that even if it can't reach 8000 RPM I may still be seeing significant power improvements over stock?

http://www.m-performance.com/Grafik/Dyn ... 500-00.jpg" ."..

I would have to say start with that Pipe

A few inches ?

you measure to whole thing not just before the expansion chamber

and some 2 strokes are picky even after the expansion chamber

so If it where me I would get a stock pipe and make it half way fit with no mods
then see what it dose then go form there

Then do you cuts turns and rotation with out shorting it or lengthening it

http://www.motorcycle.com/how-to/how-twostroke-expansion-chambers-work-and-why-you-should-care-3423.html

http://en.wikipedia.org/wiki/Expansion_chamber

Speed

"largest contribution towards achieving the current high power levels from the two-stroke Engine has come from increasing knowledge in the area of exhaust system design."

"expansion chamber must be of the correct length to ensure the pulse waves are reflected to arrive at the exhaust port at the proper time."

at came right of A Graham Bell, two stroke tuning handbook..

the expansion chamber has more to do with the power than one might think..if you buddy is a sled tuner then i would think that he should know all about 2 strokes and how pipes affect an Engine..just my 2 cents

Any two stroke will run without a tuned exhaust I have seen them running with no pipe on them but to make designed power you really need a pipe that is designed for that Engine application.

Some engines are really sensitive to the tune of the pipe alter it slightly can have dramatic effects on the HP, torque, jetting can even be a nightmare .

sorry to say it buddy but you will need to have a new pipe made. Turbotexas had 1 made for his Tripple e car from power pros that was very cheap for a custom built pipe. If some one out by you cant make you a pipe I would contact them.

SOOOOOO slow... The progress is slow but that's the problem when you count on someone else. The guy who has it is good and I trust him but he's got a lot of folks to keep happy.

He hit a wall on getting more RPM's so he decided he'd call up a buddy who has a stock vmax 500. It was actually an older model Engine of the 500 and he couldn't fit the muffler so he wasn't expecting much.

After tooling around to squeeze a hundred RPM here and a hundred there, just plugging the pipe gained him 2000RPM and got it all the way up to max HP!!

The good news is, he found the problem. The bad news, you guessed it, back to the drawing board on the pipe. I'm hoping he'll still keep working on it for me.

I owe a big appology to AK and a few others that were sure it was the pipe..... you were were right....

How about these guys?

http://www.aaenperformance.com/Snow_Home.asp" ."..

Oh,congrats on finding the problem!

You see Wayne-Ak!...He apologizes man! Now put that gun away.

Asasan,

No apology necessary, I've been there done that 4 times before I got it right.

Bazz,

Naw..... for the really big game, we don't use guns here in Ak, we Harpoon them

Ak

I got these updated pictures of the mocked up new exhaust. The old pipe was so cut up I had to order a used one of ebay and start over. here is the new planned location. It's not perfect but the last set up was far from perfect looking and was simply unusable in terms of flow.

what the hell is that from? A big rig? Why don't you go get a fmf silencer off ebay that is only 12 inches long and 2 1/2 inches in diameter and put a 30% angle bend on a piece of tubing and weld it to the pipe then install the silencer so its nice and clean and inside the cage and level with the buggy. Im sorry but the huge silencer is overkill and when you roll the pilot you will thrash the pipe and maybe send it into your fuel tank. Not to mention its quite ugly sticking out like that

Big-rig! Ha!

I agree with Shooby,plenty of room there.

Ok ok easy there haters. It was for mock up only. My tuner had it on hand so he used it. We'll work out the details here soon. I believe he used a street bike can.

No hating man just good old critizism lol. Safty first. To each their own. Hope I didnt offend you.

Well, at long last it's done! Here is a video of it running.

<iframe width="560" height="315" src="http://www.youtube.com/embed/j1FCfZrscDQ" frameborder="0" allowfullscreen></iframe>

http://youtu.be/j1FCfZrscDQ" ."..



As for my impressions, here we go.... I set out to build a pilot but faster, pretty simple. I was really focused on doing thing right so it would last. On the challenge of fast, I don't claim to be super smart in many things but I've owned nearly 50 ATV's in the past 15 years, everything from Basters to Banshees to 200sx to the great quadzillas.

I am not joking when I say that this is fastest atv I've owned. It is absolutely scary fast, under full throttle, the front end looses all traction and just feels like its floating over the road, any bump and the front end pulls up all together. It gets up to max speed in what seems like only a couple of seconds. My tuner who personally races closed course street bikes and drag races snowmobiles (not to mention owns a speed shop) was shocked when he finished. He couldn't figure how how the acceleration was night and day compared the sled it came out of. It would undoubtably make a stock 500XT Yamaha look like it was standing still. Once he was reminded of the gear box reduction issue it all made sense, that and the fact that it runs out off gear at only approx 60mph. For a idea of how quickly it builds speed, on that run down the driveway in the video, it was fully topped out before making the turn into the dirt. He belives that after he redid both the full exhast and the air intakes it's making it's full 90HP

I've got some minor odds and ends to deal with. The thumb pull it simply too hard. I also noticed that the oil injector line isn't returning. I'm going to kill two birds with one stone and pull the oil injector and mix my gas.

Honestly, the biggest problem I have with it is the speed. I had it up at Rausch Creek this weekend and I boarded on unusable, it doesn't like low RPMs so it was constant battle of keep it on the trail. It's handful for sure. RC is super rocky, if was up on the RAC trails it would do better. I'm not sure what to do at this point. I'm afraid I've built exactly what I planned on, the issue is (and I'm not ashamed to admit it), I'm not sure I'm the right rider for it.....

Awesome dude!You can tell from the vid that thing is quick!
I told you (probably lost after the hack) that Engine was going to be like a switch.
I think you will get used to it,just keep riding it.Its like the first time you ride a cr500,you think NO WAY,but you get used to it.

Congrats and I'm glad you stuck in there.

Looks like that thing runs damn good. I am glad to see it finally come together
for you. You will get used to the power eventually!




Make sure the Engine does not require oil to the bearings. I know the rotax i am putting in my pilot does. My 570 yamaha however does not so i can just mix my fuel. I am assuming your yamaha Engine would be the same? Just don't want to see you burning up the Engine now that it runs good!