what belt?

[The Hunter]

Hi all, it's been a while since I updated what's been going on with my JD300 sled. A while ago I was trying to put together a walbro carb for it, but gave up on that since I needed parts which seem unavailable. (Throttle and choke shafts to start with). Anyways I put a mikuni VM-34 carb on it, and that seems to be working really good so far, plugs are reading a little on the dark side, but no bad. It has a slight miss at and just above idle, but I have points and condensers which should take care of that.

I have a few issues to figure out yet, one of them is when I take off @ WOT I can hit 7000 for a short time, and then it revs down to around 5500. I suspect the belt is incorrect. It has a comet duster primary and the standard secondary.

What belt would you guys recommend for this setup?
What kind of rpms should the kolher k295 rev at, at WOT?
What would the top speed be on this sled, I can hit 50 at best?

Thanks.

[tmartin]

I am having a similar problem with my 400. I put a comet 102-c on it. I believe one of the clutches shifting too early. I think it is a combination of the two clutches on my machine. I am going to try to tighten up the secondary spring and see what happens. I think what is going on in mine is that the belt gets to the bottom of the secondary and there isnt enough spring tension to counteract the primary so, in turn it lugs the engine down. My 400 is real quick from 0-40 but after that theres nothing. You can actually here the shift. I will be experimenting with my clutches and I will let you know what I find. Too long of a belt would give it a dog at initial engagement and limit your speed but you wouldnt see a change in rpm. Too narrow would give you a higher engagement point due to extra room between the clutch face and belt and again would limit speed but souldnt change rpm.