HS 40 New Issues Valve guides?

[Polaraco]

It's me again.

OK after many hours and mountains of frustration, I have good consistent spark now. Turns out the after market coils are not working very well in this engine. So i reused the original coil. I heat shrunk the coil wire.

I have fuel and spark but no start. I started to investigate the intake valve so see if it's stuck open. I poked through the plug hole with a small screw driver. It is not open. But it wiggles around all over the place when it's open. I'll have to pull the head and side cover off now.

Before I tear into this new problem, I wanted to know a few things. I doubt the valve rocking around is normal. I'm thinking the spring is off and it may need a new valve guide. I thought I read someplace they were replaceable. Anybody have any experience with this?

Rivits, did you say the intake valve is open twice? This one opens twice in the same cycle. The second stroke opens slightly, shorter duration than the intake stroke

Any input on this would be appreciated

Thanks in advance (Again)

Merry Christmas

 

[ILENGINE]

Tecumseh traditionally uses valves with oversize stems, instead of having replaceable valve guides, or installable valve guides.

 

[Polaraco]

Tecumseh traditionally uses valves with oversize stems, instead of having replaceable valve guides, or installable valve guides.

Thanks IL

I stand corrected on which valve it is, it's the exhaust valve. The reason I thought it was the intake is because it had vacuum, but low compression. To my surprise, it turned out to be the exhaust. Turns out the lash is really minimal, so I will let it go.

Knowing I had to go into this anyway, I opened it up and found the valve was not going all the way down. It was against the lifter and still had like .001-2 eyeballed, opening. Wish I had some plastiguage in that range. Tapped on it a few times thinking the lifter was hanging up, but still stayed there. I checked the top of the cylinder head for flatness. Looks like the seat did not sink. But the head gasket looked like it was leaking along the valve train.

I think I'll order a new exhaust valve and the few gaskets I need and go from there.

 

[Polaraco]

Here's another question

According to the distructions, there is supposed to be between .004 to 008 valve clearence. I have .013 on the intake. Where would all that extra wear be? Lifters and Cam? I realize it's only .005, but it would be nice if I could close the gap some easily.

You guys know these little kickers better than I do.

 

[motoman]

Polaraco, Happy holidays. Sometimes I wonder if you are kidding. With due respect please explain how you "eyeball" .001." Love your usage "distructions." Winging it cause I do not know your model... Excess clearance can come from carboned seats which pull the valve towards the chamber, cam lobe wear which is apparently pretty common according to the forum input and most likely, rocker looseness. When my Intek ground off the cam lobe to a circle there was no wear on the lifters at all. May your investigation be successful and Happy New Year.

 

[Polaraco]

Hey Moto Merry Christmas to you too.

I'm always fooling around, even when the heat is on. In my young and stupid days they called me HawkEye around the ambulances. I try to make lite of everything. Being a first responder for 25 years, it's helped me stay sane. (people around me wonder about that, even my Doctor) I'm the same way at igottacummins.com. But I am there like you guys with answers. With things the way they are these day, us oldsters need something to prevent losing it.

I figured there was wear in the cam causing that gap. I am assuming when I lap these new valves in I'll be grinding a tad off the valve stem too to make it fit. I remember I had to do that on a briggs many moons ago. BTW, the valve ports were whistle clean inside.

I thought about the seats being carboned. Not the case. The valves are remarkably clean and carbon free after all these years. There is no ridge in the cylinder either. This is set for 1800 RPM. I'd still like to know what was holding the valve open though.

Oh yeah. The 001/002? I been doing this schtuff for decades. After a while you learn.

I used one of these. LOL

 

[Polaraco]

Anybody know where I can get an intake valve for this? Jacks has 18 of them on backorder. That's doesn't sound good.