help guys l'm stumped

[jbetts15]

put new points and condencer in my JD 70 (VH 70) took the head off and clean inside and got a new head gasket for it, as l was turning the motor over by hand l noticed that on the compression stroke the intake valve does not close all the way (exsplains why it was always hard to start) at first l thought it was a week spring but even pushing it with my hand as the valve closes but stops at the same place about 1 too 2 mm's from closed theres nothing blocking the valve from closeing so l'm stumped ???????????
could it have some thing to do with the camshaft ????? l have tryed every thing that l know James

[Archdean]

I would consult a spec manual for that engine , I do know that what you describe is a method of detuning an engine by the Manufacture for whatever reason!!!

I really can't help you much , sorry!

[dirtybernie]

theres a few dif jd forums on the net. you may be able to find a little more info but ive heard about valves stretching thus having to be ground a bit to get them back to spec. whether this aplies to yours im not sure. HTH bernie. :fing32:

[jodyand]

Could it be a compression release? I know some are that way the intake valve don't close to allow the motor to spin.

[professor]

Is there a cover that you can remove to see the place where the valve contacts the valve lifter and see if there is a gap - indicating possible carbon build up on the valve causing it to stick. I know on Kohlers the exhaust valve is held open longer to relive cranking compression - the automatic compression release- but I've never heard of one on the intake. I had an old Brigs that did that over the winter and it had rust on the valve seat. I got rid of the rust but never let it sit on the intake stroke again. Another poster recently had a sticky valve freed with Marvel mystery oil.
I hate to say it, but there are some sharp mechanics over on the GW. If we don't know maybe they will.

Mike

[Ingersoll444]

I doupt its a compression release. Most I have seen are on the exoust side. You would not want it blowing through the carb. I would pull the breather cover off to see how it looks. See if the valve it going all the waw to the lifter/tappat/cam how ever it is set up. May be bent, may be stuck, may be something at the bottom of the valve holding it up. Pull that breather cover first, and eyeball it.

[DYT4000]

I doupt its a compression release. Most I have seen are on the exoust side. You would not want it blowing through the carb. I would pull the breather cover off to see how it looks. See if the valve it going all the waw to the lifter/tappat/cam how ever it is set up. May be bent, may be stuck, may be something at the bottom of the valve holding it up. Pull that breather cover first, and eyeball it.

I agree with Ingersoll444, Follow the path young Skywalker!!! You will find your answer!!

[aguysmiley]

I too agree with Ingersoll. The only compression releases I've ever seen were on the exhaust valve. Changing the direction of airflow through the carb would have a bad affect on the way it runs. Sounds like it's sticking or there is some kind of interference. Maybe the valve had been replaced and the valve lash was never set?

[bigl22]

check for bent valve--- carbon buildup in valve guide-- metal burrs in valve guide-- and check cam for worn lobes and check to see if wrong valve is in place - maybe simply too long - valve lash adjustment too - - either way -- intake valve needs to come out --