| Author | Message | ||
     Kenb |
blown clear out, 1" piece out of gasket on pushrod side, compression loss enough to effectively kill front cylinder. I limped home the three miles on one cylinder, loud as all heck. I bought this bike used and someone had told me it had a bad front head gasket, so I just replaced all top end gaskets. I think this time I'll check it for warpage. I was curious if I maybe jumped on it too soon ? bike had been running 10 to 15 minutes before i romped on it. | ||
| Darthane |
That's more than enough time for it to warm up. It's most likely just a bad gasket or not quite installed correctly. | ||
| Fullpower |
lost a front head gasket on the sportster a few years ago. was on a road trip, full camping gear, and my son riding on back. was running 12.5 to one compression, burning methanol. had one saddle bag full of spare fuel. so we rode home 110 miles from hope to homer on one cylinder. with 729 cc, we had no trouble keeping up with the group. sounde d terribble though. tore the heads off, carved just under 7 cc's of aluminum out of each head, bought the cranking pressure down to 205 psi. now it runs on gasoline, and have about 20,000 miles since with no problems. | ||
| Fullpower |
much better fuel economy with the gasoline burning motor. alcohol is really fun, but not practical for daily transportation. | ||
| Smoke |
check your cylinder liner for flatness with cylinder. tim | ||
| 1320 |
I've run anywhere from 10-13.5/1 compression and as long as I was using the Cometic 3 piece gasket I have never had a head gasket failure...But, I learned this from having some failures with the coated fiber type gaskets...another trick I learned from a shovelhead rider before I switched to the Cometics was to spray some high temp aluminized paint on the fiber type gaskets just as you install them. This made the clean up of the mating surfaces a little more tedious on later rebuilds but again, no failures when using this technique... | ||
| Kevyn |
Remember to install the Pig Tails! | ||
| Kenb |
uh oh !! pig tails ? what be them ? | ||
| Kenb |
Should the liner extend from the cylinder deck or should it be perfectly flush ? I read the gasket surface checking section; Checking Gasket Surface If either cylinder gasket surface does not meet flatness specifications, replace cylinder and piston. Proper tolerances will extend component life and prevent leaks. 1. See Figure 3-29. Check that cylinder top (head) gasket surface is flat within 0.006 in. (0.15 mm). Lay a straight edge across the surface, then try to insert a feeler gauge between the straightedge and the gasket surface. 2. Check that the cylinder base gasket surface is flat within 0.008 in. (0.20 mm). Lay a straightedge across the surface, then try to insert a feeler gauge between the straightedge and the gasket surface. but it makes no mention of this. | ||
| Mikej |
Discussion on pigtails: http://www.badweatherbikers.com/cgibin/discus/show.cgi?tpc=3842&post=83385#POST8 3385 |
