Needing help !

[rustyxm2]

I'm new to the forum with my current scooter project
A 50CC limited edition scooter that I have since converted
To 100CC has the Hp cam and big valve head
Along with the Hp variator with 5.5 sliders and am currently running
60 jet on the carb runs decent enough
About 55mph with me on it I'm a big guy around 6-0
235, but I recently had a serious issue where I was riding along
And the exhaust literally vibrated lose from the head
But I didn't know until the next morning that it was completely off
The studs ! I tried to start it the next morning and got nothing
It kicked over but didn't even try to start about three weeks prior to this I actually was having issues starting it and idling it would just
Die but it ran fine after the engine was warm, in getting back to
The original issue I took in to my local scooter shop and he told me that it over heated and that the rings had lost there tension and my current compression ration was only 105 he said this happened because the oil was only half full which I disagreed with only because I check my tire pressure and oil levels every time before I ride unless the new engine was using allot of oil but it Ali ready has 1,500 miles on it so I dismiss that, so my first question would be if I ran about 45 minutes with out the muffler on the head would that cause the rings to go bad ? Cause this is a new bike that is only four months old and that shouldn't happen to the exhaust to get loose that bad, he also said I had a ring that was hanging up and he was able to loosen that up but the thing that is so proplexing is the scooter seems to run exactly the same I find this hard to believe with only 105 PSI compression when 90 and below won't even start your engine at this point it's hard to trust the information that I have been given I was told 145 PSI is normal for this application then I see videos of compressions that are up around 175 PSI as being normal so I don't know what to think at this point ? Your advice would be appreciated

[rustyxm2]

I wanted to add this the scooter is running better then ever but I'm not sure that I can trust in fully, I use it mostly to get to and from work
And am using a max of 3/4 throttle as of now

[90GTVert]

It's possible that you ran it lean and something has gone wrong. The 60 jet sounds very small and if you had a bad exhaust leak it would exacerbate any lean condition.

You add that it's running better than ever. If you mean that you did end up starting it and right now it's great, then I wouldn't worry about the 105psi. It's an error or some sort. These things don't do 50MPH with low compression.

[Fox]

The exhausts job is not only to quiet the engine but it also draws off heat and dissapates it so if it becomes detached from the head and you continue to ride it like that then you can damage the exhaust valve. The hottest part of the head is around the exhaust port. Running with a loose or detached pipe will allow that heat to build to a point where the valve itself can get so hot that it burns/warps and the valve seat can also get burnt so you now have a valve that doesn't seal all the way closed which = low compression/low vacuum which causes hard starting, stalling, rough idle etc...

My advice would be to remove the head and shoot some WD40 into the intake and exhaust ports to visually test the valves. You can use any liquid like water or whatever. I use WD40 cause it is a petroleum product that inhibits rust so it's an ideal liquid for the test.

This guy uses water on a car head. You just point the exhaust port up and shoot liquid in it and watch. You then rotate the head so the intake valve points up and repeat. Any leakage is a compression leak. You don't have to fill the port all the way. Usually a good healthy 2 second shot of WD40 is enough.




A new set of acorn nuts is cheap. Get 2 so you have extras. Lock washers are your friend.
www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR0.TRC0.H0.XGY6+acorn+nuts.TRS0&_nkw=GY6+acorn+nuts&_sacat=0

[gsx600racer]

Mar 1, 2016 14:00:46 GMT -5 Fox said:

The exhausts job is not only to quiet the engine but it also draws off heat and dissapates it so if it becomes detached from the head and you continue to ride it like that then you can damage the exhaust valve. The hottest part of the head is around the exhaust port. Running with a loose or detached pipe will allow that heat to build to a point where the valve itself can get so hot that it burns/warps and the valve seat can also get burnt so you now have a valve that doesn't seal all the way closed which = low compression/low vacuum which causes hard stating, stalling, rough idle etc...

My advice would be to remove the head and shoot some WD40 into the intake and exhaust ports to visually test the valves. You can use any liquid like water or whatever. I use WD40 cause it is a pertoleum product that inhibits rust so it's an ideal liquid for the test.

This guy uses water on a car head. Yoiu just point the exhaust port up and shoot liquid in it and watch. You then rotate the head so the intake valve points up and repeat. Any leakage is a compression leak. You don't have to fill the port all the way. Usually a good healthy 2 second shot of WD40 is enough.




A new set of acorn nuts is cheap. Get 2 so you have extras. Lock washers are your friend.
www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR0.TRC0.H0.XGY6+acorn+nuts.TRS0&_nkw=GY6+acorn+nuts&_sacat=0

Comment about video.

I did not know that the artist formally known as Prince made a new video. "When exhaust valves cry"

[Senna1Rossi]

WELCOME!