Compression

[dusty1]

Did a compression test on the 73 FLH today.Bike sitting since mid seventies (friends barn find). 20 psi front,45 psi rear. Thats with oil added through spark plug hole. Top end time. Will start tearing down soon.Cant get tappet screen plug out,so i might put a little heat around it with a small propane camping  torch and keep using JB blaster to try and work loose. Im tempted to have a look in gear case,but im afraid of what i might find. 

[76shuvlinoff]

That is definitely low but who knows? Maybe you'll get lucky.

[Ohio HD]

Well, if there are any issues in the gear case, you'll find out the easy way, or the hard way. Which do you prefer?

[dusty1]

Yeah i guess i'd better take a look in gear case, (if it were my bike i definitely would). I don't think owner realizes how costly parts are to get this bike on the road again. Over all bike in excellent shape.Pulled heads today,haven't disassembled yet.  .010" o.s. pistons,glazed cylinders. Never dealt with a bike that has sat this long. Should i replace gaskets in this, (tappet block & oil pump)? Gaskets 40 years old. Am i correct in assuming they will degrade and lose sealing ability over that amount of time?       

[JW113]

Sitting since the mid 70s? Sounds like the rings are not sealing due to rust. There are so many tales of barn finds and resurection with no intervention, you have an awesome project on your hands. If it were me, it would be: lots of WD-40, clean the carb, clean the tank, fresh oil, and try to fire it up. If the ring seal is bad due to age, it will likely come back after it runs for a while. You have nothing to lose, either it will find it's mark, or you will have to do a rebuild. Why not give it a chance?

-JW

[crock]

A little MMO in the gas and oil could help as well

[biker3r]

I agree with JW and Crock, give it a try

[dirtymike]

run it rich with a little mist of oil through an open carb. If you can do it riding all the better. rusty rings