Project trimoto 175

[old-yellow]

So today I picked up a mint 1980 Yamaha DT 175 dirt bike that I plan to use the motor to convert my trike into a 175 with a manual clutch but I have a couple questions for the veteran builders that have done this before, so the questions I have is what exactly do I have to change in the transmission, I know I have to change the output shaft that comes out the left side off the engine that the sprocket rides on, the second question is that the 175 engine is a six speed and mine is a five speed, so what I would like to know is can I just change the shaft and keep the six speed or do I have to put all my five speed transmission parts in it to change the shaft.

Thanks, Alex

[dcreel]

How different are the engines themselves? Can you just put the motor in it?

[old-yellow]

yeah I can just put the engine in it but I still need to change the output shaft that the sprocket goes on because they are different length sticking out the transmission for the chain to line up to be straight and it would have kick start instead off pull start. people have done this numerous of times on here so I just need to know what I have to change in the transmissions. Thanks, Alex

[Vealmonkey]

I don't think the parts from the 80 engine will work. I was told 76 or 77-79. You may want to double check with the tecate kid on this.

[old-yellow]

Veal, I was looking at the bike and on the top tube it says that the manufacturer date is 06/79 but the title says its a 1980 so I am confused what one is it.

Thanks, Alex

[the great gazoo]

Alex, the mfg date is usually a few months before the actual release date. A bike mfg 6/79 is most likely an '80 model.

[old-yellow]

Thanks gazoo. Hey veal is the motor you used a five speed or a six speed?

[Vealmonkey]

Five Speed I'm pretty sure, but it didn't run so I didn't check it. My engine is definitely a 77 though. Look at the engine cases and such but the later model engines were different internally and externally. Also the yt engine has a "knockout" in the top of the engine cases and that is where the clutch release mechanism goes. You have to use the yt gears, but you have to use all the clutch parts from the it175 and I think you have to use the it main gearshaft as it is hollow and that is where part of the shifting mechanism runs. You can remove the oil pump and use the it175 clutch side cover buy you will have to close up the hole for the kicker gear. And it's way simpler to just use the recoil starter from the yt175. I think the only thing that you could use from the 80 it175 is the 6 petal reed cage. Other than that, I don't believe any of the other parts are compaatable.

[the tecate kid]

Alex I just swapped the complete IT motor into mine. You will have to trim some off of the head for your exhaust to work, and fabricate a brake cable mount for the rear pedal. I dont know alot about the DT motors, but I do know that 79 was the last year for the IT motors to interchange. I used a freeze out plug to block off the kicker hole, and used my stator from the tri moto on the IT engine in order for the recoil starter to work. Very simple swap really. Yes you do have to split the cases and swap the counter shaft, but just get a good Clymer manual. Its not that bad.

[old-yellow]

well today I removed the engine from the dirtbike because I am planning on using the DT175 cylinder on my engine, also I think that I have a way to use the clutch because I noticed that the only differences is that the YT clutch shaft doesn't have a hole drilled through it for the clutch pushrod to go through it like the DT does, so I was thinking if I took it to the machine shop and had them drill it all the way through and had them make me a shorter clutch pushrod because the one in the DT is longer because its a six speed and not a five speed like the YT engine that I should be able to use the clutch.

[old-yellow]

I forgot to add that obviously I will need to use the manual clutch basket assembly and the the piece that goes in the engine case for the clutch cable to attach, also veal the DT cylinder does fit on my YT engine all I have to do is use different cylinder studs.

[old-yellow]

So I gave up on the whole clutch thing today and Just decided to use the DT 175 top end on my engine and all I have to say is holy that made my trike a fire breathing demon, I took it for a couple rides and it will do wheelies all the way through third gear, the only problem is that I have to get a new throttle cable because mine is not long enough to let the bigger carb close all the way, so I am going to try and use the one of the dirt bike and I don't think I will be able to use my stock air cleaner setup but I have not tried it yet.

[bansheejoel]

sweet man thats awesome news to hear!!!! I have a question, what year dt175 top ends work? Also what size carb and what exhaust are you using? I really want to put a 175 top end on mine but dont want to spend aton of money since im just using it for ice fishing and screwing around with as i have my banshee when i want to go fast but i would love a 175 top end with the front suspension you have. That is becoming a very nice trike!!

[old-yellow]

I am not sure on all the years, Vealmonkey and the tecate kid would know that better but I would say 1977 to 1985 for the cylinders but I am not a hundred percent sure, anyways the IT, DT, MX model dirt bike's are the models with the cylinders that will go on are engine.

[old-yellow]

I forgot to mention but I am using stock 125 exhaust and the stock VM 24 carburetor that came On the dirt bike.