Non-adjustable valves?

[ThePiglet]

I found an abandoned 12/24v Honda ED400 generator by the bins a few weeks ago and decided to pinch it to tinker with.

It didn't fire and there was barely any compression so I've stripped it down and found the exhaust valve isn't completely closing i.e. it's not being dropped far enough.

The problem is, on opening the valve spring cover there is no obvious way of adjusting the clearance. The valve stem sits in a small seperate 'cup' which may possibly be used as a way of adjusting (thicker/thinner base of 'cup' between stem & push rod), has anyone come accross someting like this before?

 

I'm tempted to just file a bit off the end of the stem or base of the cup & grind the valve in again.

[Bobbybass]

Not familiar with this at all..but its not 'shimmed' is it..?

You dont just measure the clearance..and then adjust it by adding or taking away measured shims..?

 

Just an idea.

 

Bob

[steelaway]

I found an abandoned 12/24v Honda ED400 generator by the bins a few weeks ago and decided to pinch it to tinker with.

It didn't fire and there was barely any compression so I've stripped it down and found the exhaust valve isn't completely closing i.e. it's not being dropped far enough.

The problem is, on opening the valve spring cover there is no obvious way of adjusting the clearance. The valve stem sits in a small seperate 'cup' which may possibly be used as a way of adjusting (thicker/thinner base of 'cup' between stem & push rod), has anyone come accross someting like this before?

 

I'm tempted to just file a bit off the end of the stem or base of the cup & grind the valve in again.

 

 

Hi

 

I would be checking what has caused the valve to stay open. Has the valve seat been hammered intop the head. Is there any build up of carbon built up on the valve.

A common Honda design is to have a shim inside the valve follower cup. Grinding the valve stem may not be advisable as the valve stem tend to be case hardened and you could grind it of, leaving just a soft valve stem.

 

Alex

[soldthehouse]

Valve could be bent after over revving

[RLWP]

Is there anything helpful in the owners manual?

 

Richard

[ThePiglet]

Thanks for the replies.

 

I have a copy of the owners manual, but it's very basic. You have to disassemble A LOT to get at this cover, so it's probably not something they consider user-serviceable.

 

I think you're right, it is shimmed, what I described as 'cups'. Point taken about grinding the stem, I'll see if a local motor factors or lawnmower spares shop carries any, if not then there seem to be plenty around online (once you know what you're looking for!).

 

The valve is not bent, has not struck the head, there is a uniform buildup of carbon around the rim of the seat and a great deal in the head itself. It's a very old generator so I think maybe the gap has simply worn down through use.

 

Cheers.

[sentinel]

Thanks for the replies.

 

I have a copy of the owners manual, but it's very basic. You have to disassemble A LOT to get at this cover, so it's probably not something they consider user-serviceable.

 

I think you're right, it is shimmed, what I described as 'cups'. Point taken about grinding the stem, I'll see if a local motor factors or lawnmower spares shop carries any, if not then there seem to be plenty around online (once you know what you're looking for!).

 

The valve is not bent, has not struck the head, there is a uniform buildup of carbon around the rim of the seat and a great deal in the head itself. It's a very old generator so I think maybe the gap has simply worn down through use.

 

Cheers.

 

Valve seat regression?

[soldthehouse]

You say the valve isnt bent but not closing and as far as I understand there is no clearance between pushrod/rocker, If this is the case and you havnt removed said pushrod rocker, you wont have been in a position to close the valve artificially. If it is bent it will most likely be at a point nearest to the valve head and this last bit will if kinked prevent the final closure of the valve. I cant see why the valve operating gear should have closed up gapwise with use normally it would be if the valve had settled deper into the seat with wear but if it is partially open as you suggest the tappet gap would be greater!

Edited January 24, 2011 by soldthehouse

[ThePiglet]

There is no rocker (as I understand them). The pushrod acts directly on the base of the valve stem (but there is this shim between the two for adjustment).

I have removed the valve and shim and without teh shim, the valve drops all the way down. This and having checked with a straight edge leads me to believe it is not bent.

[soldthehouse]

There is no rocker (as I understand them). The pushrod acts directly on the base of the valve stem (but there is this shim between the two for adjustment).

I have removed the valve and shim and without teh shim, the valve drops all the way down. This and having checked with a straight edge leads me to believe it is not bent.

Is it a side valve set up

[soldthehouse]

Aye up how about this

http://engines.honda.com/models/model-detail/gx160

And click on automatic decrompression bit for starting. This leaves the exaust valve open

Edited January 25, 2011 by soldthehouse