Questions

[Cheapinri]

Finally got it running sort of seems to only like full throttle and sticks full forward. Engine runs ok at all rpm ranges , was hoping it would like driving slow but it doesn't

[dirtdobber]

What kind of machine, engine and clutch setup do you have?

[Cheapinri]

Old chaparral with jlo 340, clutch unknown . If i give it 1/4 throttle and push sticks forward it goes a couple of feet and stops. If i give it 3/4 throttle and move sticks slowly foward it does the same . Full throttle and push sticks foward fast and it jumps up and moves about 25 mph .

[Cheapinri]

Thinking belt or clutch , hoping to rule out transmission

[Mike]

It does sound like a belt issue. Have you checked the belt tension or the condition of the belt to make sure it's not loose or worn?

[Cheapinri]

Belt seems loose to me i could pull it up and take it off transmission pull simply by turning the pulley don't see any way to adjust it. Not sure how tight belt should be . So guess I will be ordering a few new belts

[Mike]

I'm not familiar with the drivetrain of a Chaparrel. Check to see if your engine mount allows you to slide it back. If not, perhaps you will have to just buy a new belt. Hopefully one of the other members more familiar with your machine can give you some better advice.

[ARGOJIM]

A 2 stroke clutch may have an engagement of as high as 3500rpm, you will need some room to test a 2 stroke machine.

Probably not going to be able to ride around 5 mph.

[Cheapinri]

Mike definitely need new belt ,from researching other post i can figure out width but no simple way to figure length. Engine has zero adjustability so belt has to be right on

[Cheapinri]

Argo Jim, i understand 2 cycle engines need to rev but a steady 5-10 would be nice is this possible?

[ARGOJIM]

I am going to defer that to members with dedicated trail 2 stroke machines, davephelps comes to mind. You may still have a belt issue as well.

[allwheeldrive]

Mike definitely need new belt ,from researching other post i can figure out width but no simple way to figure length. Engine has zero adjustability so belt has to be right on

I had the same problem.

What you can do is cut long strips of cardboard of the same width as you belt. Double them up to make same thickness of your belt (inner one a little narrower to simulate the angled edge). 60” should be planet.
Then wrap it around your clutches. Trim to proper length. Then measure. Mine came out to 49” But when I bought a 49” belt it was just a little too tight. Where 52” was too long and 51” may be too long as well. So I’d say add 1” to what you get in cardboard and you should be good to go.

[Cheapinri]

Ordered new belt at 43 inches old belt measured at 44 and was really loose