58.5mm kit installed and a lot of vibration

[jpcjguy]

Hi all,

So I have a Kandi Sypder that I picked up for cheap. I got it running and it smoked like a son of a gun. Figured rings. So I bought one the kits - decided on a 58.5mm kit. First time ever doing something like this.
New to buggies in general. Got it all back together and it ran!
Followed these instructions for the most part - http://www.thejunkmanadv.com/uploads...gy6_engine.pdf

At idle the thing vibrates big time. I don't recall it doing this before I did the kit, but then again I only fired it up a few times for about 5 - 10 minutes and that was 4-5 months ago (busy summer).

Here is a video I took - can't really tell vibration but maybe the sound helps:
https://drive.google.com/open?id=0B7...XdkZmtKZE02b0k

Oh - I also put in new roller weights and springs - but I did that before I did the big bore kit.

Any thoughts? What type of things should I check? I did a quick compression test and got it up to 160psi several times. Could something in the CVT come loose/seize up?

Thanks!
Joe

[charleswrivers]

Mine ran a little... off... as the rings seated. Not rough though. I had to redo the valve lash as the first time I set it it was too loose and caused a lot of valve noise, but that was easily noticable as the valves we're audibly slapping a bit. If the only variable is motor rebuild, then I doubt the CVT is the cause.

I'd take the valve cover off, check your 4 bolts are tight, the lash again, check your timing right. Theres not much else you touched. I just did the same thing a month ago, only I stayed 57.4. The lash was all I had to go back and do. I didn't have excessive vibrations... it just ran 'right'. It's still waaay tighter but then again, that's just the difference of a fresh higher compression engine and a tired low compression one.

[jpcjguy]

Originally Posted by charleswrivers

Mine ran a little... off... as the rings seated. Not rough though. I had to redo the valve lash as the first time I set it it was too loose and caused a lot of valve noise, but that was easily noticable as the valves we're audibly slapping a bit. If the only variable is motor rebuild, then I doubt the CVT is the cause.

I'd take the valve cover off, check your 4 bolts are tight, the lash again, check your timing right. Theres not much else you touched. I just did the same thing a month ago, only I stayed 57.4. The lash was all I had to go back and do. I didn't have excessive vibrations... it just ran 'right'. It's still waaay tighter but then again, that's just the difference of a fresh higher compression engine and a tired low compression one.

I will double check the valve lash again. Good idea. I torqued the 4 head bolts to 14 ft lbs. I think that is what I read. I will double check them and the timing. For timing it is just have the hash mark line up with the dash before the "T", right? and make sure that the two holes on the camshaft gear are parallel with the case.

I guess I should pull the exhaust and put it on stand and check the CVT and and make sure everything looks like it is moving ok.

I did drive it a little this morning - up and down the street. Appeared to drive fine - although there is not much torque - paused on a steep incline (ditch on side of the road for water run off) and it could not move. I had to let it roll back and start again. It is a big buggy and my almost 240lbs probably don't help. Wonder if I should have got a 250cc.....

[charleswrivers]

Mmmm... that sounds wrong. I have ditches I go in and out of w/me and a couple kids for 250lb of weight and I don't even have to hit the throttle too much. They're not real deep but the sides are steep.

As to timing, yes... here's a good link w/pictures.

...NM that link is blocked. If you Google GY6 setting timing the fist link will have instructions and pictures.

If your off by a tooth you'll be down on power, and these 150s need all they can get, but if it can't make it out of a ditch that sounds like it's very down on power. I only have the one buggy but the idea that the engine is vibrating sounds all wrong. It's not like your new piston is wobbling in it's new cylinder... so it doesn't make much sense.

[jpcjguy]

Originally Posted by charleswrivers

Mmmm... that sounds wrong. I have ditches I go in and out of w/me and a couple kids for 250lb of weight and I don't even have to hit the throttle too much. They're not real deep but the sides are steep.

As to timing, yes... here's a good link w/pictures.

...NM that link is blocked. If you Google GY6 setting timing the fist link will have instructions and pictures.

If your off by a tooth you'll be down on power, and these 150s need all they can get, but if it can't make it out of a ditch that sounds like it's very down on power. I only have the one buggy but the idea that the engine is vibrating sounds all wrong. It's not like your new piston is wobbling in it's new cylinder... so it doesn't make much sense.

Thanks for the link - this is the buggy depot technical center page. I checked that out. One thing I noticed is that when I tried to get the lines lined up as in this pic below, it kept rotating a little on its own and be off by 1/4". Like it would rotate to a "dip" (probably the crank settling). So what I did was use a socket extension on one of the cage fins to hold it in place.

I guess my timing might be suspect now....

[charleswrivers]

I kept putting mine on and felt that I was always off by a tooth. It'd look right when I put it on the cam, but by the time I had tightened the rockers down it never seemed right. I'd just double check it and see.

I never second guessed myself as much on a regular car as much as a gy6. I don't know if it's because the cam on these has a smaller circumference so you feel like your between teeth to be exactly perfect or what...

I know visually, the piston pauses at TDC for a moment and you can probably have a tooth worth of play because I looked at it w/the head off.

[jpcjguy]

Good call. I will start there.

[jpcjguy]

Ok. So I had some time again last night and reviewed everything. I believe I have the timing set properly. I assume you set it with the chain tensioner off. I had it lined up perfectly without the tensioner and when I installed the tensioner, it rotated slight (logical).


https://drive.google.com/open?id=0B7...ng0ZGlmbmtiZVE


Here are links to the CVT runnning:
https://drive.google.com/open?id=0B7...GNlQVN3dmJjRms

https://drive.google.com/open?id=0B7...lEtWmFQRUF0aDg

Other videos of her idling:
https://drive.google.com/open?id=0B7...3gtVm5wU3lHdEE

https://drive.google.com/open?id=0B7...09EMW1ZUDhHWFE

Oh - and I did a compression test and got to 160psi several times.
I also run a yellow torque and clutch springs and 12g roller weights and the Clutch Variator is brand new

[jpcjguy]

any thoughts?

[jmansracerocket]

you did check valve lash ? sounds like the valves need to be adjusted. also the correct amount of oil in there?