Valve adjuster problem

[ministock7x]

My problem is the intake valve lash adjuster moves after 30 to 45 minutes of running. It doesn't loosen, it gets tighter. The lash gets less and less untill it bottoms out on the valve and holds the valve open to the point that there is no compression and the motor quits running. I readjust the valve lash and it fires right up, runs great for another 30 to 45 minutes, the the lash closes up again. GRRRRRRRR This is very agrivating. Any sugestions? Thanks.

[EJ Mac]

Not sure if this will help or not but here is a link that is very helpful on doing this, maybe it will help, if not it could be beneficial to others http://49ccscoot.proboards.com/index.cgi?board=4ttech&action=display&thread=428

[BuggyMaster]

Is it a new head? The reason i ask is that it is common to have to adjust the valves after a few months on a new machine. What happens is the valve seats are moving upward into the head thus allowing the valve / stem to come up higher (towards the rocker arm) and that's where you lose your lash.

Springs that are too strong will cause the same thing.

Any mods?

[olderthan]

torque the headbolts before you adjust the valves

[SYCARMS]

What are you setting the valve lash at? TOM

[ministock7x]

Original head, ported and pollished, new Big bore kit (jug, piston, pin, clips), 6 and 6 on lash, usual clutch mods, Intake moves to tighter than zero,

[ministock7x]

I runs like a scalded dog right after I readjust the valvas.

[ministock7x]

Well, like I would imagine a scalded dog would run if scalded, I have never actually seen a scalded dog. lol

[SYCARMS]

This may seem like a lame question but are you adjusting the valves when cold or when hot. TOM

[BuggyMaster]

Who did the porting and polishing on it? My guess is that it is in fact your valve seats sinking in. One of two things will happen: 1.) they will finally get to a point where they no longer sink and be fine or 2.) Something went wrong with the port and polish where the surface that they are installed to us not holding up and they will continue to sink until they can go no more and something breaks. Hopefully the first option is the correct one.

[ministock7x]

This may seem like a lame question but are you adjusting the valves when cold or when hot. TOM
Operating temperature when adjusted.

I did the port and polish, I have done a bunch on my race cars so I felt confident doing this little head. I didnt remove that much material, mostly cleaned up the combustion chamber and runners and gasket matched them with a good polish. I did have this problem before mods were done also. The rings went away is what prompted the B/B kit.

[SYCARMS]

The valve lash on these engines are adjusted cold. Intake .003 exh. .005 Try this method and let us know the results. The head with all its components are made using several different metals all with different expansion rates. I cannot give you an answer as to why but any small engine of this type the instructions call for valve adjustment to be done on a cold engine. And my Honda manual says to never adjust valves on a hot engine. Try adjustment on a cold engine (ambient temp) than let us know the results. TOM

[olderthan]

when i raced vw buggies valves set on cold engine
samarai 4x4 offroad valves set on cold engine
howhit 150 based engines set on cold engine
let your motor set overnight then reset

[ministock7x]

10-4 will try that again.

[ministock7x]

OK I readjusted the valve lash this morning but haven't had time to test drive. The young-uns have been gone all weekend, they are my test pilots. They are a bit more easy on the toys than me, I seem to be kind of rough. lol WE will probably go riding next weekend and get some good trail testing in. I will let yall know how it goes.

[olderthan]

hopefully setting the valves cold will solve your problem

[ministock7x]

I think I might not have been getting the jam nut tight enough also. I cranked down a bit more than I have done in the past and made sure I had a good hold back on the adjuster when I tightened the jam nut.

[kliff]

Yup....if'n it ain't at least 1.5 grunts, up to maybe 2 low grunts tight, they will loosen up.

[ministock7x]

Well, I was gonna try it out yesterday, and the starter craped out again. This is the 2nd starter in less than a year. I dont know how many the previous owner went through if any. Is there a problem with the GY6 starters or am I just the "lucky" one? Is this going to be a continuous thing? Lord I hope not.

[olderthan]

i am on my original starter
never had any problems from it

[SYCARMS]

I have 2 model 2004 buggies and had yet to have a starter problem. Are you sure it is the starter and not the solenoid. TOM

[ministock7x]

I have 2 model 2004 buggies and had yet to have a starter problem. Are you sure it is the starter and not the solenoid. TOM
Yes, very sure, Took starter off after checking solenoid and put 12 v directly to it. If I spin the shaft when voltage is applied it will run. If I dont spin it, sometimes nothing, sometimes alot of heat and smoke. I may have been sold a 2nd hand starter when the first one went bad. It looked ok and worked fine at the time. But oh well, its only time and money right? More time and more money. I will buy one from a different supplyer now. 10-4:biglaugh:
By the way Tom, Did you get my last email? *****2005 Tomberlin Crossfire 150******