Hi all,
I decided to take the intakes off the carbs on the left side for cylinders 2 and 4 to look into the carbs. I looked down into the intake on the head and it is an ugly site. I mean really bad looking inside compared to my 78 parts bike. When I look down into the intake of the head I see a lot of build up of something not sure what anyway both intake valves were closed and I could see a puddle of gas at the end of the valve. I assume this is because all the build up in the chamber prevents the gas from flowing smooth down the shaft.
What has caused this build up I am not sure maybe the bike was laying on the left side when it was not being used and oil leaked into the intake. Anyway when you look down to the valve you can not even see where the valve seal is it is so bad. The valves do open and close correct but I think they are not sealing because of the build up.
I plane to pull the head off and see what the cylinders look like. according to the pressure of 155lbs they should be in good shape I hope. So I plan on taking off the heads and doing a really good cleaning job on them and reseat the valves into the head with just some valve grinding compound. I call this a South Western PA valve job some people may call it or know it as a West Virginia Valve job.
I will have to look tonight in my complete gasket rebuild kit and see if it has new valve seals. Most likely not so I will have to find out where I can get them. I would rather try to clean up the heads on the 76 instead of using the heads off a 78 since the Cams have already seated them selves into the 76 heads so this should be better to just try and redo the 76 heads.
So as bad as the intakes are and the intake valves are I would expect that the valves are not sealing and that is why I can not get any vacuum reading on the number 2 and 4 carbs.

Thanks
Bob Mc
GWRRA # 155293

By Stuart Oltman on Friday, April 20, 2001 - 11:02 am:

Bob,

If the valves weren't sealing, you'd have a hell of a lot less than 150 pounds of compression. You say you get no vacuum reading at all from #2 and #4? You do get vacuum on the other side of the motor, and those cylinders have the same compression as 2 and 4, right? I think you're about to make a lot of unnecessary work for yourself.

Take a close look at those intakes you just removed. Remove the vacuum port screws, and poke a sharp skinny object like a small screwdriver through the threaded holes. You may find that some of that "ugly stuff" has effectively welded the holes shut on the inside.

By Bob Mc Wee on Friday, April 20, 2001 - 12:13 pm:

Hi,
Well I did make sure the holes were open on that side. Yes the other side has the same compression. What worries me is that the intake shaft is not clean like on my 78 parts bike and the valve steam is also not very clean like the 78 I look down there and it is very smooth and clean and I can even see the nice clean area that the valves seal to in the head but can not see any of that in the 76 head.
The bike runs pretty ruff and when I gas it it seems like it is starving for fuel and the fact that when I looked down the intake I could see a puddle of gas tells me that all the gas that goes down the intake is not getting to the cylinder and may be causing me problems.
Keep the comments coming I am open for any and all.

Bob Mc
GWRRA # 155293

By Rich Davison on Friday, April 20, 2001 - 02:49 pm:

If the gas was puddling up behind the valve then I would guess they are sealing pretty well and that the carbs are in need of a rebuild. Check the oil for gas and change it if it smells at all like gas.

Rich