Engine rattle and no power on start up.

[dcalce]

I hate to ask a question that has already been answered but I can't seem to find the answer for which I'm looking. I bought a gas Yamaha cart for $100 so you can imagine the state it was in. It actually did run and but smoked like a good sized forest fire. So I took it apart. Rebuilt the engine (thanks to a lot of help from reading this site) and now the engine runs great. My problem is when starting from a dead stop, the engine rattles like it is coming out of the cart and there is no power (torque). One the cart starts moving and the pressure is relieved it runs out beautifully. But with two people in the cart it almost will not move. Again once it is moving it does fine. I just don't know if this is a clutch problem, a motor mount problem ( I did replace one of the mounts that was broken) or an engine problem. I even tightened the engine stability cable a little beyond tolerance. I topped out the cart at 22 mph, by GPS, for a very short time (no governor) so I know the engine is capable. Does anyone have a solution that might get me off the line without the rock and roll and rattle. One last thing. After putting the engine back together and also putting the cart back together I saw an insert I missed. That is, that the clutch should have gone on aligned to the shaft a certain way. I do not know if I lined it up as instructed (odds are I did get that lucky). Would this make a significant difference and should I pull it all off and line it up as diagramed. (new drive belt installed)

[abieex]

What year cart (a couple of pics please) is it? Sounds like a clutch/belt problem to me. Put the cart on stands and watch the clutches work. Are the both going full range of motion on the sheaves? Belt in tolerance? Sheaves cupped? Springs in tolerance? Identify noise as to clutch or engine. Its a process of elimination.

[DOOmsman]

Did you replace the motor mounts?

[sho305]

If the engine moves towards the trans under torque, it will bog badly on takeoff. The mounts and tension cable keep that from happening. If not that then the clutch may have a problem and be trying to engage at low rpm. Is the belt the right size and engine in right place, they usually have around 1-2" of play at rest in belt center. Could be a problem with the secondary and the belt is getting sucked down into it at takeoff. The spring on a 4 cycles cart is wound (preload) at least one ramp, so the ramp is sprung against the plastic shoes, then push the outer sheave on the key and get the nut on quick.

[dcalce]

Thanks for all the help. I looked at the working of a cart that functioned properly and discovered the following: It looks like the rear sheave on my cart doesn't move at all. The drive clutch is engaging at low RPMs and the drive belt is much larger (longer) than the on the observation cart. I did order the drive belt for a 1992 G8, which is what my cart is but the belt is so large it will fit easily over the rear sheave with no need to even turn the sheave. So now that I understand the workings of all of the components I think I can begin to solve all the problems. Thank you all again for your help.

[Mike Mac]

The belt should install pretty easy. The movement of the clutches is what takes the slack out of the belt. The motor mounts need to be in good order, making the motor line up in a specific position in the swing arm. The tensioner cable needs to be in good condition, and about 1/16 inch gap at the tensioner nut.

2 pumps of grease in each zerk fitting on each clutch. The ramp shoes (3 of them) need to be in the helix on the secondary clutch.

If all that is correct, then remove the clutch cover on the primary clutch (on motor), and check the weights,, again 3 of them. Make sure they are not sloppy loose or one is not broken or out of place.

If none of this works, jump over to the the "G8 Club", and have a good laugh!!

[sho305]

My G9 you have to turn the secondary to install it, it will run the edge and pop on. With a stock spring you can lock the brakes and turn the secondary off the ramps by hand, then it should slide in with some force against the spring. May have to remove the rear body to get at it well enough to grab it, and easier without a belt on it.