Died because of seal?

[rossness]

What a weird title....

I just finished pulling the engine in my 650 and replacing valve stem seals because I was burning oil on one cylinder. Put it all back together and buttoned up, rode it down the block all proud and BANG! Two loud backfires and DOA. I think it’s the clutch pushrod seal as there was a ton oil sprayed all over my chain and out from the left side cover, however it wasn’t POURING out. Also, the bike wouldn’t start (cranked the starter with choke, etc. This bike has always started on the first kick/turn). Am I right in thinking it’s the pushrod seal that’s causing the engine to not run as well, or should I replace that and look elsewhere?

Thanks in advance! I’d have no idea how to do anything on an engine without this forum (not that I know much).

 

[gggGary]

My armchair guess is that for some reason your crankcase got highly pressurized, that blew out the clutch seal. Pull plugs, look and check compression?

 

[motormike]

Wild guess.. but when ya toss'd the engine back in the frame.. pinch...crimp the crankcase breather tube...?

 

[rossness]

Sorry for the late reply. I'll check those things today. I'm 98% sure my breather tube is good as I was REALLY careful about that and had it pulled out of the way when I put it in. That one busted seal (at the pushrod) would be enough for me to lose compression and not start correct? I'm going to change it and check today, but just so I have a frame of mind to start at.

 

[5twins]

No, that blown seal wouldn't keep the bike from running, it'd just leak a lot of oil. That seal wouldn't cause the engine to lose compression because it's not sealing the cylinder and head, just the crankcase. It quit running for some other reason.

 

[rossness]

Gotcha. That was my main wonder. I'll go through the typical non-running symptoms then and update! Thanks!