New member with 1983 yt175

[Mattjmulligan]

Hello, I'll start with the fact that I'm totally new to trikes, but not new to forums or air cooled Yamaha 2 strokes. I will also say that my grammar and puntuation sucks, but I try to keep myself from running on. So bear with me.

Now to the three wheeler... I picked this thing up in a trade for a couple of puch mopeds I had laying around, it's a 1983 yt 175. It's missing a bunch of nuts and bolts and a few odds and ends but it's mostly all there. I picked up a parts bike yesterday for it, i had assumed it was a 175. Turns out it was a 125, But it was 30$ so I bought it anyway. The guy says it's an 85 but no way to tell for sure because he cut the front end off for a go cart project, so no frame vin number to go by.

Now my questions..
What (if anything) is compatible between the two?
The 175 seems to be stuck in reverse?? (Do these have reverse?) when I pull the starter the wheels spin backwards. And I can't get it to shift through any gears.
I've seen that a few people put the 175 top end on the 125 bottom, is there any advantage to this?

I will edit in and add other questions as I think of them, any other help is appreciated.

Thanks a lot,
Matt

[Mattjmulligan]

Well after looking at some micro fiches I found some information.
Apperently there is no reverse, in either bike. So i assume the there is something seriously wrong in the transmission on the 175? Although I could be wrong
I also found the cylinder base gasket to be the same but the crank, rod, wrist pin and little end bearing are all different, so I'm not sure about the top end swap yet, although I have seen a few posts saying that they have done it.
The rear axle assembly is the same between the two, so that's a score on an extra rear axle assembly.
All the wheels are the same, but the 125 wheel has no brake setup.
The rear fenders are the same, but the 125 fender I have is trash anyway, but a good spare nonetheless.

[dgm635csi]

There is probably nothing wrong with the transmission, but the pull starter has definitely been put back together backwards. Take it off the engine and inspect the rope routing. It should come off the top of the starter pulley and loop around the small roller and out the hole. Warning, reassembling the pull starter once you have taken it apart to fix it can be a real PITA. Next, download the service manual. The clutch may be out of adjustment which can make it very difficult to shift through the gears. As far as I know, the transmissions are the same between both models, but the clutch assemblies are different. I am 99% sure that the primary gear reduction ratio is different on the 125 and 175, so 175 clutch basket and primary gear will not work in a 125 bottom end.

[BigHarp99]

You need to talk to ddiger, he mashed a 125 & a 175. I have a YT 175, 1983, bought it for $20. Runs great, but transmission needs work. Waiting on parts at the moment.

[Mattjmulligan]

Thanks guys, I didn't even think about the pull starter being wound up back wards, I'll just put the pull start off of the 125 on for now until I get it running. (Don't feel like rewinding a pull start, done enough lawn mowers, weed whackers and leaf blowers to know its a pain in the but lol) Thanks for the link to the service manual, I was wondering where I could find it online.
I'll finally be able to get into it today, I'm gonna clean it up a bit, put the right nuts and bolts in place, adjust the clutch and try to get it in neutral and get it fired up. If it fires up and runs good I'm not gonna open it up, just change the oil and get it all cleaned up and better looking. I'll try to get some pics up today.

[BigHarp99]

Sounds good. Can't wait for the pics.