1990 DS Carburetor Backfire

[ckiguy]

Originally Posted by Dreamer

OK Upon further inspection of the valves it looks like the exhaust valve is not closing all the way. There is close to a quarter inch gap between the tappet and the valve stem when it is closed. Also I am going to remove the body so I can get my head in there better, but I cannot get a .004 gauge to go in at the intake valve? What would be the fix for the stuck valve? Thanks for the pics in the manual. I need to order one for sure. Thank you for the help!

pull thhe head and make sure you just dont have a carbon build up on the valve or valve seat. this way when you put head back on after inspection on the inside, you cand set the valve clearence. plus when you pull the head you get a closer look at the top of the valves . it should be a l head desighn like on a briggs or techumsech motor. or meaning the valves are on the side of the piston.

[stinger5]

Originally Posted by Dreamer

OK Upon further inspection of the valves it looks like the exhaust valve is not closing all the way. There is close to a quarter inch gap between the tappet and the valve stem when it is closed. Also I am going to remove the body so I can get my head in there better, but I cannot get a .004 gauge to go in at the intake valve? What would be the fix for the stuck valve? Thanks for the pics in the manual. I need to order one for sure. Thank you for the help!

I'm thinking broken valve spring here.

[Dreamer]

Will you guys forgive me for my lack of knowledge and experience with motors. I took the head off and found just a bunch of carbon build up on the piston and the head. So when the piston is in the bottom of the cylinder and the valves closed I stuck a feeler gauge in the intake valve and I came up with .014 and on the exhaust I came up with .005. I can tell the bottom end of this engine has been opened up because I can see orange gasket sealer around the case.

[stinger5]

Originally Posted by Dreamer

Will you guys forgive me for my lack of knowledge and experience with motors. I took the head off and found just a bunch of carbon build up on the piston and the head. So when the piston is in the bottom of the cylinder and the valves closed I stuck a feeler gauge in the intake valve and I came up with .014 and on the exhaust I came up with .005. I can tell the bottom end of this engine has been opened up because I can see orange gasket sealer around the case.

Lack of knowledge is how we all came here Dreamer, no worries. Take a look at this simple diagram and see if it explains things mate; Just hit the red logo to cycle through.
http://www.gill.co.uk/products/digit.../6_4stroke.asp

[Dreamer]

Stinger Thanks for that little diagram, very helpful. I was having a heck of a time figuring out when I was supposed to measure the valve clearance. I found that I am missing a tappet cap on the exhaust valve. I still cannot get a gauge in the the intake valve when at TDC of the compression stroke. I am going to try to locate some of these tappet caps and get the valves adjusted correctly. I will report back with the results. Thank you guys for the help. My son and I are gaining some knowledge together.

[jace1975]

Dreamer, here's the "engine" section from my manual to help you out. Will take a few posts to get it all with the maximum set at 5 attachments per post.

Jason

[jace1975]

and again...

[jace1975]

and....

[jace1975]

AND....

[jace1975]

Finally, the last page..... Hope these help! Oh, and no makin fun of my lack of scanning skills!!

Jason