Need Help Yamaha YT

[cooperkustoms]

A buddy of mine gave me the 3 wheeler. I am in the process of rebuilding it. He told me he thought it had DT175 jug and head on it. After doing research I am not so sure. I pulled these numbers off the motor. Can anyone tell me if the bottom end is a YT125 or YT175. 3X3-000657. Any help would be appreciated.

[Rural Newfie By]

pretty sure 3x3 is a ytm125j, 1980 I think, I have two of em. best way to tell about the jug is to look at the stamp at the very bottom. if it says '171CC' then it's a 175 top end, if it says '123CC' then it's a 125 jug. both sizes of engines have the same bottom ends though.

[cooperkustoms]

Rural...thanks for the info. So it looks like it is a 125 with a 175 jug. Do you know if DT and YT 175 parts in interchangable?

[old-yellow]

Welcome to the forums and yes some parts from the DT175 are interchangabile.

[MonroeMike]

Welcome to 3ww.

3X3-000657 = 1980 YT125 (G)

[Vealmonkey]

Pretty much the dt and yt have the same top ends, but the bottom ends are very different. Dt is of couse 5 speed manual trans with a narrow main shaft. You can bolt a whole dt175 engine into a yt175, it's a direct bolt in, but the difference is where the front sprocket of the dt and yt end up. The dt front sprocket is too narrow and the chain hits the frame and doesn't line up with the yt rear sprocket. The top ends are exactly the same though. If you wanted the better top end, then you would have to use an it 175 top end. Much better porting than a yt or dt175 and much better port timing also. Better reed valves as well. But the dt and yt 175 top ends are exactly alike and the parts are exactly alike.

[cooperkustoms]

Excellent information guys. I really appreciate it. I will be posting pics of my progress on here.

[Vealmonkey]

Also, if you start checking into it, the 80-81 125s are alot different than the 82 and later 125s. Very few parts are interchangable between the early and later model 125s. The early 125s have a smaller clutch basket than the later 175s so you may notice slipping of your clutches with that 175 top end. The early shifter link assemblies are much punier than the later shift assemblies. The frames are different, even though you can put the early or later engines in either frame. You can't put a suspension 175 kit on an early 125 frame without doing some welding. The early and the later rear axle bearing carriers won't swap out because they are different. The handlebar off/on switches are different, well at least between the 175 and 125. And there are a bunch more differences I can't remember. The 82 and later 125s and 175s are better made than the 80-81 125 in my opinion. And I've had an 80 125 and now a 82 yt175.

[old-yellow]

Hey Cooper read this whole thread.
http://www.3wheelerworld.com/showthread.php?86220-Pro-Tec-175-Beginning

[cooperkustoms]

yellow....thanks for the thread...I will keep it as a favorite.