The motor has never been apart other than removing te valve covers once last spring to adjust the valves. Sounds like a project for febuary when I get my taxes back. May go ahead and check valves again and get new gaskets for the covers and spark plug tubes. Cash is slim at the moment and dont want to have the bike down for a couple months if this is as bad as it gets. Hoping its just the oring at the top of the plug tube. Will try to check it out next week end and let ya know how it goes. Thanks!!
The motor has never been apart other than removing te valve covers once last spring to adjust the valves. Sounds like a project for febuary when I get my taxes back. May go ahead and check valves again and get new gaskets for the covers and spark plug tubes. Cash is slim at the moment and dont want to have the bike down for a couple months if this is as bad as it gets. Hoping its just the oring at the top of the plug tube. Will try to check it out next week end and let ya know how it goes. Thanks!!
No sweat, Rick. Hope it's just that too and I hear ya on all the rest. Get a complete top-end gasket/O-Ring kit when you do the work and keep us posted.
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It ain't about where you live; it's about how you live. So, ride to live, Bruh.
Pulled the covers today to check valves and put new o-rings on spark plug tubes. Exhaust on front cylinder cam showing wear, and 1 valve was tight, .005 smaller shim. Intake lobe on back wearing also, 1 intake valve needed shim .010 bigger. Looks like will better tearing into in couple months.
This was the front cylinder, maybe .015-.020. Rear wasnt this bad, just enough to catch my finger nail.
You put some miles on it for sure. Some of my higher mileage vehicals have used a little oil but usually stop for a while after changing it.
Acceleration smoke would lead my to think blow by as in ring wear that sfair mentioned. Doing a compression test that you planed might show this but it sounds pretty minimal at this point if your not blowing blue smoke or smelling oil all the time.
Pulled the covers today to check valves and put new o-rings on spark plug tubes. Exhaust on front cylinder cam showing wear, and 1 valve was tight, .005 smaller shim. Intake lobe on back wearing also, 1 intake valve needed shim .010 bigger. Looks like will better tearing into in couple months.Attachment 14424
This was the front cylinder, maybe .015-.020. Rear wasnt this bad, just enough to catch my finger nail.
Was 70 today, wanted to ride all day, but had give a little TLC 1st. Rode about 90 minute. At American Legion Christmas dinner now. Probably wont do much else with it till feb., waiting for tax return. Well, I'll ride her, but that goes without saying.
Cams, once they show wear, usually have a short life after that and they can wear in a hurry.
800's have been know to drop valves, and that is something you do not want to happen!
Sooo, if your engine is blowing smoke, valvetrain is showing its age, it might be time for a teardown. Continuing to ride might not be a good idea.
Cams, once they show wear, usually have a short life after that and they can wear in a hurry.
800's have been know to drop valves, and that is something you do not want to happen!
Sooo, if your engine is blowing smoke, valvetrain is showing its age, it might be time for a teardown. Continuing to ride might not be a good idea.
SFair's right and this is good advice Rick. The 800 doesn't need to have the entire engine torn down to change camshafts but if you are up against that much mileage then a complete teardown cleaning/inspection/rebuild is a good idea to replace anything that has reached or passed its service limits if you haven't already done that. I only say this because it seems you like your bike and intend on keeping it. I once read on here about a member's bike suddenly dropping a valve one morning when he started his bike. He had someone use an internal engine camera to diagnose the problem but all he had to do was take the heads off to see that. Anyway, I assume this is what you meant when you said you would work on it during the winter.
Because you will be hard down without riding and if this is your only bike it's a major drag for serious riders like yourself to spend all this time unable to ride and having to check valve seat angles/diameters, valves, camshaft runout and height, camshaft/cap clearances, camshaft journal diameters, camshaft chains, camshaft tensioners, camshaft sprockets, rocker shafts/rocker arms, cylinder walls, piston rings, pistons, crankshafts, trans etc. etc. etc. and so basically you can classify this as a rebuild but it's all worth it in the end.
You are up to the task though and you should come out just fine. The only thing I wanted to emphasize is that the camshaft cap is machined/mated for the head it comes with and if the cap is beyond service limits I would buy a new head and trade in the old one for a core if the old head is beyond service limits or get the new camshaft cap machined/mated for the old head if it is still within service limits. I've heard about people replacing camshaft caps and installing them on the old heads without having them machined/mated and having some serious problems after that. Keep us updated and hope you had a good Christmas Dinner.
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It ain't about where you live; it's about how you live. So, ride to live, Bruh.
Last edited by Comanche; 12-02-2012 at 02:24 AM.
Reason: Clarification
Have done minor rebuild a couple times on Chevy 350s, so have no fear of doing this myself. Spec I was looking in manual for, but didnt find was the valve to piston clearance. Have checked this on V8s by puttng a small amount of putty on the top of piston and mounting the head as you would to run it, then slowly rotating the engine in its normal rotation. Then disassemble and measure the thinnest portion of the putty. This is useful for determing how much the heads can be milled to correct minor worpage, and increase the compression a small amount. Understand how bad dropping a valve can be, just helped a friend replace his motor due to loosing both exhaust valves on the front cylinder. He found a motor for 1,200 with just over 8,000 miles. This bring up the question of, would it be better to just find a low milage motor or do a rebuild on mine.