I have just put a new top end on my lt500r and now I'm hearing a noise from the motor. It sounds like a tapping noise. I had just bought the quad and was having a heck of a time starting and then keeping it running after it was started. I waas told it was from low compression. I pulled the head off and found a large gouge down the cylinder and also found damaged reeds as well. I assumed this was the problem. I bored it .100 over to make sure it would clean up and installed a weisco piston. I replaced the reeds with new carbon boyens reeds. I also figured I would get a new carb. I bought a 38mm PWK off ebay that was said to be run only a few times. When I received it it still looked brand new, I just wasn't sure about the jetting yet. Over the last few days I got everything back together and kicked it about 3 times and it fired right up. I let it run for a few minutes and then shut it off. The next day I re-torqued evrything an fired it up after a couple of kicks. Sitting on top of the bike, everything sounds normal, but when I lean down by the motor I can here a tapping noise that is pretty solid sounding. I am assuming that I will have to tear into the motor but I am looking for advice on what to look for that might be making this noise. One thing I was wondering is could this be from the carb being to lean. I took it for a short ride and notice that after about 1/4 throttle that it is missing and losing power. I only rode it for a few minutes for fear of damaging the motor. The noise has not gotten any worse but it is consistant from when I first start the motor and seems to increase when the rpms are increased. I am running super unleaded gas in it.

 

what size headgasket did you bye. they do tend to make noise . nature of the beast.hate to see you tear it apart but some times you just need the piece of mind that nothing is rong

 

Was thee head milled?check the squish.Piston could be hitting the head.

 

I did mill the head but only .005 but I do not know if it was ever milled before. I think I will pull the head and check things out. Maybe the head gasket is too small. It was late at night when I was putting it back together and could have easily over looked the head gasket being too small. I don't remember actually checking that.

 

I had a busted exhaust valve governor in mine that made noise...just an idea. Simple to check!

 

How do you check it? I am kinda new to working on two strokes.

 

1st check to see if it works...just look thru the sight glass on the right while you rev it up. You should clearly see the lever moving up and down in sync with the revs. Remove the right side case to access the governor. Drain the coolant first.

 

I am kinda scared to rev the motor due to fear of damaging it. I do recal that the are that connects to the valve seemed loose or like it wasn't connected to anything. I tried to gently pull the arm out of the case to see if it was loose but it was still connected to something. I was alos a little uncertain about the assembly of this thing. I bought a Suzuki manual that was burned onto a CD and the quality is pretty poor. It didn't seem to have much info on the exhaust valve. I will pull the cover and check things out. Thanks everyone for all the help! [quote]
1st check to see if it works...just look thru the sight glass on the right while you rev it up. You should clearly see the lever moving up and down in sync with the revs. Remove the right side case to access the governor. Drain the coolant first.

 

The mystery has been solved. I removed the head to look at the gasket and it was fine. I examined things more and found that the piston was hitting the head from boring the motor .100 over. It was just the outer edge of the head and it looks like there is no damage. Monday I will machine the head to the diameter of the bigger bore so that there is enough clearance. Once I had the head off, I sat it back on and pushed the kick start lever over. I could not feel anything. I then removed the head gasket and did the same thing again. This time I could feel the piston just touching the head as I turned it over. I could tell on the piston that it had been tough as the motor was running. Hopefully this will let me get it running where I can start trying to get the jetting set. Thanks for everyone's help. [img]i/expressions/face-icon-small-smile.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-smile.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img]

 

my bike is 100 over and i did not have to do anything to the head. i just ran into a problem with the headgasket die to small and the piston hit it on an over rev and dented the fire ring.other than that it ran all summer even made some dyno pulls with no problems.i then found out they have oversize gaskets for biger bores.