Valve stem seals, possible with head in place?

[iansimpson]

Wondering if it is possible to change the valve stem seals with the head in place? If possible how do I go about this? Thanks!

[nitroeagle]

I know you can on cars, should work on bikes. The tool is the tricky part. Set the cylinder on compression at tdc, so both valves are closed. Screw in the adapter from a compression tester & supply constant air to the cylinder. In theory the air pressure should hold the valve up. You would still need the tool for removing the valve springs though. The head itself really isn't that hard to get off. I'd rather just remove it to do the seals. Plus you can check the valves & seats & clean them if needed.

[davesee]

volker has a little write up on here of his experience with it...i believe he doesn't feel it's much of a shortcut.

i have one that's gone, too, and it is a tempting mid-season fix.

[iansimpson]

Upon further review, the head doesnt seem that hard to get off and I think I will take it off to inspect and clean like you say nitroeagle.

the only valve spring compressor I can find around here is one like this
http://toolsandmore.us/oem25220-overheadvalvespringcompressor.aspx
will this kind fit our heads or is it too big? the guy at the store thought it would be too large for a motorcycle. was only $15 though so could be worth a shot

[hondamark]

this how i found how to do it. its not my video, i came across it looking how to do seals.

http://www.youtube.com/watch?v=n_9Y8Y2vEXw

[iansimpson]

have you tried that hondamark? I dont want to have to track down that tool, I would rather just get the valvespring compressor for $15 and go about it. Ive got an oilleak from the outside valve cover bolt and it seems that means that the o rings between the cylinder and the head have gone, so id like to change them too while im in there.. PO left me a head gasket but I dont think there are orings, anyone know where i would find some?

[nitroeagle]

I haven't seen that tool before. I like it. Doesn't seem bad. I've only used the c-clamp type. I've seen another style for cars, it has size adapters. I guess it depends on the state of the engine & how comfortable you are.

[iansimpson]

None of the shops have the c-clamp style ones, Im ordering one tomorrow. head is off, and its not looking too good. granted this is the first old motor ive taken apart, but there are large chunks of carbon all over everything and on the valves, and thick on the pistons. gonna spend a bunch of time cleaning i guess

PO left me a head gasket but it turns out its not the right one, cylinder spacing and head bolt spacing is the same but the cam chain gap isnt, its short by about an inch on each side. if anyone knows what model this is off and needs one i will happily give it away.

[nitroeagle]

You're probably better off going that route(taking the head off). Get everything nice & clean. Might as well lap the valves too. Good luck with it. I think I'm in the same boat this winter.

[nitroeagle]

As a side note. I did the seals on a '68 Falcon I had with a straight 6 in it. Heavy sucker, cast iron with intake cast into it. It had a lot of carbon built up in the combustion chambers & valves. Cleaned everything up & after I was done, it 2 miles per gallon more. 22mpg, not bad for a 40 year old car.

[iansimpson]

thats not bad at all im excited to get it all together, kind of a bummer to have to do it mid season but thats the way she goes. glad i did, one of the valve cover bolts was stripped and im going to need to rethread it, it was leaking oil pretty bad out the top end for the last week i had it on the road. PO had a bunch of rubber washers and they all deteriorated last weekend.

[hondamark]

i actually bought the tool in the video. it will be used when I have to do the valve seals on my 16v dodge spirit.

but with my loss of compression on cyl#3 i didnt really need the tool since i am pulling the head off now and could have made my own with a large c-clamp and a piece of pipe with a notch cut out. however investing in tools is never a bad thing in my mind.

[davesee]

probably late on the draw here, but a harbour freight or princess auto small c clamp style compressor worked for me with a brass nut with a slot cut out of it. 12$ and 20 minutes.

[iansimpson]

Davesee, Im heading to Princess in about an hour to pick one up

[Volker_P]

Done this.
Please have a look at the Valve stem seals: may the head stay in place? thread.

I repeat you'll really need good nerves if you try this for the first time.
The first one took me two hours or so. Went better with practice.

Might work much better with proper tools in case they exist. Guess not worth to make them yourself.

The head gasket with the different cam chain tunnel is probably CB500/CB550. Maybe overbore if the cylinder holes fit. These engines are quite similar but have no morse type but a normal cam chain.