200s and 185s motor differences?

[jtatc200]

Hi Guys,
New here to the forums and this the first question I am posting. Hopefully someone can help. I own a 185s and a 200s. Now the 185 frame is not in the best shape. and the 200 motor cases are not in the best shape either. I was wondering the if there werean real motor differences between the two bottom ends? I guess I am thinking I might take the 185s bottom end and split it and use the cases for the 200s if they are the same. Also are there any differnces with the head? Again from visual inspection the 185s head is in better shape than the 200s head (ie some goof made a mess of the threads in the exhaust port. Any help appreciated guys.
J

[jtatc200]

So no one knows if I can use the bottom end cases from the 185 for the 200?

[starky1234]

hold on someone will help

[trizilla]

does the 185 engine run? if it does, why not use the whole thing in the 200s? i think the stroke on each is the same just different bore size. the 185 cases may not accept the 200 cylinder without some material being removed. other than bore size i think the engines are pretty much the same. as far as the head is concerned i also think they are the same. hope this helps

[thefox]

The bore size is the difference. The 200 top end will fit on the 185 lower end without a problem. Cases and head interchange.

[jtatc200]

Thanks for getting back guys. So I guess that I can then take to two motors and basically make one decent one out of all the parts. Now when you are talking about the bore size are you talking about the diameter of the cylinder? Or the part of the cylinder that fits into the case?
Thanks

[Yamada]

The 200s piston will be to big ( piston diameter) to fit in the 185s cylinder. The 185s piston will be too small to fit the 200s cylinder.

[Custom200]

You can just put the top end off the 200 on the 185 base..Why wont you just bolt the 185 directly in the 200 Frame?

[jtatc200]

The only reason I won't be putting the 185 motor in the 200 frame is because some idiot welded the sprocket gear on the transmission output shaft and that gear being welded to that shaft totally screwed the up the motor. It also is pretty rough and needs to be rebuilt too so I was wondering? Why not use the 185 cases for the 200 rebuild.

[topless]

I used a 185s bottom end, bored the cylinder for a stock 200x piston (compression went from 7.8 to 10.2), ported the head and did a valve job. Then bolted it into my 200s trike.
It runs great. The 200s motor had issues with the clutches and (what's with dummies and welders?) the shift lever welded on.