hey hows it going guys, I am new to this forum and do not currently have a odyssey or pilot but have always wanted one since i saw the movie "heavyweights" back in the day when i was little lol. Anyways i am currently rebuilding a 1984 ATC300R and was pointed to this direction from fellow members on 3wheeler.org and Airfoolers.com. As many of you know dealing with your odysseys and pilots sourcing parts can be a real hassle, and i am having one heck of a time trying to source parts for the 300R top end and threw out my time spent working / learning about this Engine i have heard about people re sleeving the 300 top end with a fl350 sleeve. I thought i would come and join up on your forum to see if i could learn some more about this modification if my Engine down the road becomes in need of the modification. currently my cylinder is at 76.50MM, i found myself a NOS 76.50 piston and rings only to find out that my cylinder was already at that size needless to say i was thrilled to hear that lol. but i recently found myself a NOS set of 76.75 rings so now i am in need of the matching piston. my search continues........

anyways here are some pictures of my progress of my 84 atc300R build.


this is when i first got the trike.

this is how it sits now, i sent the rear shock to suspension 101 out in Cali for a rebuild and to have it re valved for 360 lbs with a new Eibach spring to match (im a big boy at 300lbs)


its been a long process and i have been slowly working on it since this past April, when i first purchased the trike i did not even no that the 300R kit was included (it was my first 2 stroke) so needless to say i had alot to learn.... it came with a full DG exhaust which i have since cleaned up and i also polished the silencer to a mirror finish.


Anyways i am glad to be a new member here and i am looking forward to learning more about the odysseys and pilots as i would LOVE to have one someday! and with any luck may be someone on here can help me out with sourcing some parts for my 300R. or at the very least teach me some new tricks and modifications that could be used to help me with my build.
thanks alot guys!
Chris

Welcome to the forum man. I had a 1985 ATC250R. It was a serious beast and I think it had to be the fasted wheeler I ever owned.

I can't help you with the 300R kit you now have on that Engine, or how you can convert it to a 350, but there are some extremely talented fella's here on this site who are very accustomed to keeping alive these old Hondas. I'm sure that someone can lend you a hand.

There are also many folks here that could hook you up with a Pilot or an Odyssey.

Again, welcome aboard!

well i picked up a 84 250r parts bike a couple months back and i was able to get the that 250R Engine to run only to find out that it had a clutch problem. So i currently have that Engine torn down a bit to repair / diagnose the clutch problem. Once that Engine is back together i will be using that Engine until i can gather all the needed parts for the 300R. i am also thinking about picking up a mossbarger reed cage and reeds since i suspect both the reeds that i have from ether Engine are not sealing correctly. (250R was running extremely ritch and was told that if the reeds are not sealing to the cage fully that could cause a severe ritch condition.) so with any luck i will be running the 250 for the time being until the 300 is all fixed.

as far as i am concerned i am all for learning anything that i can from you guys!. so the more info the better lol. and some day after the 300R build is all said and done i would love to get into a pilot! i have never seen one of those bad boys in person but from videos i have seen they look to be one heck of a ride!. but until the R is all set i don't think i could take on another project lol.

thanks for the warm welcome buddy.

I see by the signature you are a VW fan?

Rand

Hi and welcome to the site, I have a 1983 ATC250R I bought new in 83 I bought and installed a 300R kit the rest is stock including the pipe.

I never heard about installing the FL350 sleeve into the 300R cylinder have you tried calling LA Sleeve if anybody has done one I bet they have, 300R pistons and rings are getting hard to come by not that I would want to use a big bore air cooled Engine on tight trails heh

yea i am a big VW fan, i have a 94 golf 2.slow, but i swapped out the tired 160K Engine that was in it for a fresh 2.0 that i built from a bare block with hopes of someday running a nuespeed supercharger but that dream has since faded. while my buddy was going to school for autobody he was nice enough to take my car in and shave the trunk, antenna and fix all the dents and dings and give it a fresh coat of plymouth forest green with a touch of pearl so it looks pretty how it sits lol. then i swapped in a mk3.5 cabrio dimple dash with all its red lit electronics and mk5 shift nob, B4 passat front tan leather seats, mk3 jetta rear bench, then installed a set of vmaxx coil overs (they are nothing special) then installed 2 alpine type R 10's with a 1000 watt 2 channel for the subs and 1500 watt 4 channel for the type R door speakers and a alpine head unit. its NO speed demon by any means but it is clean as heck for its age and is nice enough to pull complements at the local shows by the mk3 fans. at the end of the day it is a nice driver for when its nice out. Then i have a 2000 jetta 2.slow also that is more of my daily car. so yea its fair to say i am a vw fan lol. i made the trip down to waterfest this year which was one heck of a good time.

there is a member on airfoolers.com that takes the spent 300R cylinders and re sleaves them with the fl350 sleeves, then runs the fl350 pistons to match, he said he can run that setup between 80-82 MM. but i am not sure if he does the modification himself or has a shop that he knows of perform the work.

when i purchased this trike back in april i didnt even no the 300 kit was with it, i didnt find out what i had until i posted pictures on 3wheeler.org and another member was like you SCORED! i only paid 340$ for the entire bike. needless to say i have a lot more into it now but i was happy to find out that i had my hands on the 300 kit. and the dg exhaust was a nice added bonus also.

i have been in touch with larry over at racers toy store for a last resort to have the modification he offers done on my cylinder but i don't really want to go that route, once the modification is done then i can never go back to the oem pistons and rings. so that's why i have been searching for the 76.75 piston. but at least at the end of the day if i cannot come up with a 76.75 or 77MM i can send my cylinder to flotek or racers toy store to get the modification done and then run the new still manufactured pistons from there on. but i would much rather stay OEM......

When I mentioned VW's I was thinking Air Cooled however, I have owned 2 water suckers!

Rand

World is changing my friend, when he said VW that's not what came into my mind, guess were getting old haha They removed the beans from the field going out in a few min to run the snot out of my Baja on the 100 acre field

Jetting old.....hell I'm already there!

One of these days I will start on my Baja. For now it just sits beside the driveway sun rotting away!

Rand

baja bugs are awesome! it must be pretty sweet to be able to go and romp in a field with one hoser lol.

On the topic of your piston and cylinder, have you checked the clearance between the piston to cylinder wall? If it is within spec (someone please chyme in on what air cooled clearance should be), then you will not need to bore, just make sure the current bore is nice and straight with a ridgid hone, not a flex hone.

Nice lookin ATC, my first "fast bike" was a 1985 250R ATC I Called it the Widow Maker. Had a friend end up in the hospital with broken ribs, collapsed lung, and all kinds of other goodies after riding it, so I sold it. I currently have a 1983 Honda 70 ATC as a pit bike.

i have not checked the clearance between the piston and cylinder wall as i do not know what the exact clearance is. My clymer manual does not cover the 300R kit so i am shooting blind. although i did bring my cylinder to a local machine shop (not that the machines't has ever worked on this Engine before anyways) but he said that alot of the scoring that is in the cylinder wall seemed to be fragments of the piston impacted into the cylinder wall but there are also scratches none the less.....
i wish there was a machine shop here in CT that has experience with this kit as i would be more than willing to bring it to them and have them tell me what exactly kind of shape it is in, but i am aware of such shops as racers toy store and Flotek. and i am not exactly thrilled to send my cylinder multiple states away just to get a diagnosis, but at the end of the day it is more than likely what i will have to do since i do want someone who has experience working with this kit to perform the machining process on it and not a shop that has never worked with one before.

here are some pictures of the cylinder

Well thanks to Pilotpete1 supplying me with some much needed 300 top end parts i am making some serious progress with the 300R build.

I just picked up the Engine from Ken O'conner racing here in CT yesterday. I gave it to ken and had him perform a full tear down / inspection, rebuild the crank shaft with a hot rods connecting rod kit, install CR500 crankshaft bearings (direct fit by the way and have 8 rollers instead of 7), perform the power player 300R modifications from the May of 1984's Issue of 3 wheeling magazine, and also perform a mild trail port job to the cylinder.

i was thrilled when i walked into his shop and saw it assembled for the first time yesterday!. I got right down to business and installed it into the chassis this afternoon. its been quite a long process and difficult process sourcing all of these parts but it is finally coming together. i still have to decide on what carburetor i am going to use, cannot make up my mind between a 35MM PWK quad vent air striker or a 38MM qaud vent air striker. tho since it is primarily going to be ridden on trails and not raced i am leaning towards the 35mm

anyways here is a couple pics of the progress