YTM200K questions

[Gstwostroke]

I recently got the above tri moto, not running, and after an initial assessment have a few questions I could use guidance on.

1- The carb system in general is a disaster. The whole throttle and cable system is pieced together from who knows what and only opens the slide about half way and there is no adjustment, the starter plunger is broken off inside the body, and the intake rubber is questionable since it is wrapped in electrical tape. After doing some searching, it seems this model is a unicorn as it is the only one that uses a spigot mount. Is it possible to cut the OEM rubber spigot off and use a clamp on rubber spigot from something else or does the design of the manifold not allow that? Maybe better to find a flange mount carb/intake from a different, more readily available model? Still would need to find the throttle and choke cables too.

2- it would seem the pull starter has been replaced with one that doesn’t have the automatic decompression doohickey. The part is still on the head and seems to function. Now, probably not going to find the correct pull start and cable for anything resembling reasonable so I was thinking there may be a manual setup that could be adapted, or is the decompression device not really necessary?

Thanks for any guidance.

[350for350]

I think that you can use the flange style carb, intake, and cables/assemblies from another Yamaha 200 three wheeler. You would/should have to use the intake as well as the carb.
I can't answer on the decomp being needed. I know that on a stock Honda 185, it's not needed. Your Yamaha may have higher compression so keep that in mind. Now if you want it, you may be able to use a manual set up off of a Yamaha 225DX/DR, but I don't know if the two work on the valves the same way or not. Not many definites here, but hopefully this will give you some directions to start looking.

[ATC King]

Get the later manifold and bolt on carb and try for OEM, either NOS or good condition used. The Chinese stuff is a mess. I put a China carb on my 200K and it took too much screwing around with as far as extra money for an assortment of jets and the time to get it close to right.

It doesn't matter what trike it is, the deomp saves wear and tear on the starting mechanism, be it a recoil or electric. My 200K has the incorrect recoil on it too and it's a pretty stiff pull for a stock engine. I haven't done it yet, but I hope to get around to hooking a manual lever on the handlebars to the decomp on the cylinder head cover. It was a common thing on dirt bikes from that era and I'm not certain why it wasn't on the trikes.

I prefer a manual decomp over the automatic ones if choosing between one or the other. Some machines have both. The manual is nice if the machine hasn't been started in a while, to use the decomp to easily spin the engine several times with the ignition and fuel off, to kind of clean the cylinder out and pump a little oil before starting. A manual decomp is essential in clearing out a flooded engine without beating on the starting mech.

The levers on the Honda's that have the rubber coated tab are easy enough to use, but the decomp lever on my 200K hurts my fingers and I need to add a handlebar mounted lever and cable to it.

[Gstwostroke]

So in searching around for a newer flange mount OEM carb/manifold/cable, the pickings are mostly individual parts or if the whole enchilada they are more that what I paid for the trike. I think I have located the stuff I need to put the original carb back into working order for a reasonable cost. The only question is the manifold. I suppose there is no harm in cutting the rubber off the manifold and see if it is possible to fit a replacement off something else. Worse case I will be committed to the flanged carb. As for the decomp, I think I’m leaning toward just fabricating a lever of some sort to replace the cable lever on the head. Shouldn’t be to hard to do. I’ll keep my eye open for a handle bar lever as a backup.

[ironchop]

Did you pay less than $90 for the trike?
Maybe make this guy an offer....

https://www.ebay.com/itm/22457789127...mis&media=COPY


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[Gstwostroke]

That is the wrong side. Since the whole air box is MIA, just going to run a UNI pod. So update on the manifold. It is possible to cut off the original and replace it. It is a bit of a pain as the original is vulcanized or something to the aluminum manifold but once I got it cleaned off I used a repro 33mm spigot for a British bike. Little snug on the manifold but was able to get it on there no problem. Fits nicely on the carb spigot also. Just waiting on a Chinese carb to hopefully rob a couple things from it to put on the original Mikuni.

[Gstwostroke]

Got it to run with the OEM carb, but was running pig rich everywhere, like the choke was on (it wasn’t, not even hooked up). Float level was spot on and jets seem to be stock. I had the Chinese carb so I figured I’d give it a shot. Put it back together and it actually runs pretty damn good. Really surprised me. Now that it runs and I have been able to confirm the trans and clutch are good I looked into why rather rear brake didn’t work very well. Basically the rear pads are worn down and the rear rotor is glazed over. My question now is how does the rotor come off the axle? I’d like to pull it back so I can sand the glaze off.

[Gstwostroke]

Oh, just found out that this would not have come with rear suspension. Had no idea these were solid in the back. I guess mine has one of the aftermarket kits.

[El Camexican]

Please post some photos up of that rear suspension. That might explain why your airbox is gone. That modification alone is probably worth twice whatever you paid for your Three Wheeler

Sounds like you’re well on your way to figuring out your carburetor issues. I hope whatever you end up with is still convenient with respect to a choke and decent air filtration system. I ended up going with the 225 intake and carburetor, but that was back when you could still order brand new one from the dealer in 2010

As far as your decompression system is concerned I highly recommend that you keep looking until you find all the right parts. I’ve had my 200K for almost 40 years and in that time I have used it with and without the decompression system, the difference is night and day, especially when it’s cold outside. Even if yours is missing the cable, there should be a tiny lever for the oem cable on the right hand side of the engine that you can lift. The 225 lever should fit on your 200 and has a nice plastic tab. Because the 225 had electric start you were supposed to just reach down there and hold the lever up while seated on the trike.

When I was in my teens I could reach over and lift the lever up at the same time I was pulling the starter cord, but it’s much better if you have a friend do it in cold weather. In warm weather you can start the trike without using the decompression lever, but every once in a while you’re going to lift your trike off the ground. Eventually something has to give, it’s usually the starter rope when you’re 10 miles from home, but at my age it would probably be my shoulder socket. I don’t know if it was my dad, or me but somewhere along the way we got the brilliant idea to replace the rope with a cable. This solved the rope breaking issue but cut a groove into the housing.

I about 12 years ago I put everything together properly with as many new parts as I could find including a new cable. 99 out of 100 times it’s a pleasure to start the trike, but unfortunately that system isn’t perfect and every once in a while all the pieces will line up in such a way that the engine has full compression. When this happens the handle is usually jerked out of my hand violently and ends up wrapping itself around the foot peg. If you want to use two hands every time it probably won’t be a problem, but when it’s working right I’m hardly gripping the handle.