Help! YTM 200 decompression?

[maxjacks40]

I've got a YTM 200N that will pull start but is extremely hard to pull. So I figured I would try fixing the decompression to make it easier. I've gone through and put it together and it seems to work because it is much easier to pull, but the thing will not start with it hooked up! Is it possible I am not getting enough compression now? Help please, I don't know what to do. Need it up and running for the weekend.

[El Camexican]

I don't have the whole set up in my memory bank anymore, but my recollection is that there is a half circle gear in the recoil that attaches to the cable and opens the exhaust valve for the first few inches of pull and then when the teeth on the half disc run out it releases the tension on the cable and allows the engine to start and run normally.

It might be possible that you have it set up so that the exhaust valve is being kept open too long, but without seeing it I can't be sure. I'd suggest asking a friend to slowly pull the cord while you are on the other side of the trike with your finger on the decompression lever watching what it does. It should be disengaged (valve closed) before your buddy runs out of rope.

Get a good idea of what the cable is doing before you tear anything apart and make sure you have a long enough pull cord. If it has been cut short then all your pulling is being done with the exhaust valve open and it will never start.

[maxjacks40]

Okay I will look at this tomorrow. But if it is staying open too long or not disengaging what would be causing it? I tried adjusting the decompression cable but it doesn't seem to do anything.

[El Camexican]

I wish I had mine in front of me, but I'm a world away from home. As far as I can recall the cable forces the valve open slightly when under tension via a small rod with a cutout in it. As soon as it is released the valve closes and only opens if the actual camshaft/rocker arm pushes it open. You may want to pull the 2 bolt cap on the exhaust side to understand how it works. It's a very simple system.

[archer45]

I had one of these but disconnected it and installed a manual lever much like Honda use on their S models. If you don't keep the water drain out of the recoil the rust will ruin them. As soon as it fires it will flip back shut on its own

[El Camexican]

I had one of these but disconnected it and installed a manual lever much like Honda use on their S models. If you don't keep the water drain out of the recoil the rust will ruin them. As soon as it fires it will flip back shut on its own

For years I used mine like that, just held it open with one hand and pulled the rope with the other. I don't bend so well anymore, so I fixed it.

[muthey]

how long have you had this 200, and did it run before you adjusted the valve relief?