Honda FT500 Ascot/350X Thumper

[Joel85350X]

I am pondering starting a side project with a 350X engine and a FT500 cylinder. I have heard that the 1982-83 Honda FT500 Ascot single cylinder streetbike jug-up will bolt onto the 350X bottom end. I checked out www.partsfish.com and the drawings indicate that the alignment pins on an ascot are the only difference in the gasket surface between jug and bottom, but I am still wondering how much different is the fit? I want to build one if it will work.

Check out the microfiche pics below.

[ATCRYDER]

Wasnt the Ascot the same engine as the XR500R but with road necessaties like e-start? If yes, This is meaning it would have reeds....

I have a feeling Billy (HONDA ATC) could be of good help here. Sorry if Im not. :(

[86350X]

Joel,,,,,, Let me know what you find out,,,, that is a great idea,,,,, I happen to have an xr500 and if I could turn my 350x into a 500x that would be unreal,,,, I never ride the 500 anyway, it just sits there,,,,, I will do some research also,,,,, Hope to have updates soon,,,,

[freaksfix]

When I had my 350X apart, I lined up the topend off my XR500 and it was way off. But if you got a machine shop go to town?

[Da_Catt]

Just looking at the two pictures of the two, i can see that the cam chain might be a problem, the hole is not is the same spot, and the bolt holes there are different. Look at the top bolt hole.

[Joel85350X]

Well, is an XR500 the same as a FT500? By the looks of the gaskets above, the very top bolt hole on the FT is the only one that looks off.

[Trikeaholic]

some guy on .org claimed to have done the XR500 top end swap on his 350X. Claimed it bolted right up with minimal "fudging". Said that he had to do something creative to oil the top end properly, but then alot of people started calling him out, no pics were ever posted (i never saw any) The posts were quite convincing, I was getting wood, then I figured If it was an easy swap, we all would have heard about it already.

[86350X]

Actually, yea they do look way off,,,,, If it was a bolt on I'd go for it, but if machining and mods are nssacary, why ruin a good 500 or 350 motor,,,,, may as well just put the entire 500 motor into the 350 frame....... just my .02

[350Xrider]

I have an XR500 as well, and I wouldn't hit a bull in the ass with the way they start. But there is something wrong with mine, it kicks back furiously every time you kick it can't even ride it now on account of it.Half of the 500's I have seen have a broken kick shaft. I don't know if the later model 500's were better or not, but i think the 600 motor is probably a better choice. Anyonelse have problems with their 500's kicking back? Even if you could put the 500 cylinder,the 500 has a way longer stroke so you would have to have a machine shop and a lot of time and money, it just wouldn't be worth it.

[Billy Golightly]

Hmm... I just made a post about this at ATV Connection today...


Take my word for it, the XL/XR/FT series topends DO NOT I repeat DO NOT fit without MODERATE modifications. I have pictures to prove so, hrc200x has them I believe. The computer that I have them on is at my moms office.

[hrc200x]

I think I deleted them pics to save on my free web space. Oops. If you need them I might have them saved to a zip disk or my h/d somewhere, let me know.

[Billy Golightly]

I'm gonna jump in chat for a few minutes if anyone else is around. I might be going to the office tomorrow, if I am I'll just upload them to the site from there and show everyone.

[Billy Golightly]

Ok, Heres the photos


http://www.3wheelerworld.com/HondaATC/350X-500XCases.jpg
http://www.3wheelerworld.com/HondaATC/350X-500XCylinders.jpg
http://www.3wheelerworld.com/HondaATC/350XCase.jpg
http://www.3wheelerworld.com/HondaATC/350Xinside.jpg
http://www.3wheelerworld.com/HondaATC/500X-350X.jpg
http://www.3wheelerworld.com/HondaATC/BotomCylinderMounts.jpg
http://www.3wheelerworld.com/HondaATC/CylinderMounts.jpg


Now, please understand I'm not saying its totally impossible...but not worth the time, money, and effort involved to do so.

[86350X]

Hey 350Xrider,,,,, its funny you should say that,,,,,, I don't know how bad it kicks back because the kickstart shaft has been broken since the day I bought it,,,,,,,, Thankfully it push starts prettyeasy with the decomp. lever, and once its running it never stalls,,,, That was my first real bike, I rode it for a good 5 or 6 years with no kicker.... got in a jam here and there, but it is a great old beast

[350Xrider]

86350x, funny you should say that.lol I to bought my xr500 with a broken kicker, i just put it together with a new shaft and now the f'ing counter shaft seal is leaking, and it is brand new. Mine however is a trailprotrailprotrailprotrailprotrailpro to start,I have to reach up on the head and push the release in and then have someone push me briskly down a steep grade. I have had mine in a few spots that it was real hard to start thats why you never ride a 500 alone.lol
I had plenty of friends to help me push it, cause there ain't no way you could push one far by yourself. I don't know about you, but my X has a lot better throttle response and revs way faster than the ole 500 though,I know thats to be expected somewhat,but once you hold that baby open a second she really starts to kick in.

[86350X]

I here ya, never ride it alone wth no kick start,,,,, My 5oo though, starts pretty easy, as long as I give it a good running start with the decomp lever pulled in in second gear,, then I release the decomp lever and it usually fires up instantly, sometimes in an unexpected wheelie,,,, lol,,,,,, Gotta keep these old hondas alive though,,,,, right????

[350Xrider]

I don't know if my xr has a high compression piston or not, but I have to put it in fifth gear in order to roll start it, and hats with the compression release pulled in, I have never been able to do it in any other gear but 4th. it usually locks the back tire up or something.Strong old bikes though.

[greenhuman]

Its the FT500 head you use, not the cylinder/head combo. The FT head will bolt up to the 350x cylinder with very slight mods. You use the 350x rocker cover to keep the original oil system to the cam etc. The FT used an internal gallery to the top end. There is a weld job to be done to the FT head so the 350x rocker cover will fit. A couple of 350x rocker box bolts do not line up but the small weld job on the FT head fixes that.
The big advantage with the FT head is the valve size. When combined with a 92mm resleeve and a Powroll stroker crank you get around 495 cc with a head that easily feeds the big CC's. I still have a modded head, so I will post a picture in the next day or so.
www.jmcracing.com.au

[Billy Golightly]

a 500 series head seems a very really possibility to me. The entire topend however is not. I have had a XR head sitting ontop of a 350 motor with no problem at all. Nothing was bolted up or anything though.