Hello everyone,

Long time reader first time poster. I had planned to sell my 93 Sporty this past summer and for a send off I promised to finally take my 8 year old for a quick ride around the block. Of course on the 5 minute ride the bike developed a problem. Lost most power, had a horrible sound and rich gas smell. Also have 'gusts of air' on my front right leg. Nursed the bike home and started my research. My mechanical ability includes changing brake pads and oil so this was something all new for me.

I can to the conclusion that I had blown my head gasket on my front cylinder. Since I was planning on selling the bike as soon as I could and given that for a 93 I wasn't planning on getting a ton, I decided to save the money and tackle it myself. Figured it would be a fun winter project. So I did lots of reading online and a shop manual and decided to buy the complete gasket kit from Cometic as I wasn't sure if I would go any lower than the head gasket.

So to make a already long post as short as I can I took my time, like a week and a half and got it all tore down, cleaned up like new and put back together. Only had a few 'extra parts' at the end. While going through it I replaced every gasket I could find. I ended up just doing the front cylinder all the way down to the piston.

So, as I said I get it all back together and low and behold, the near exact same issue remains.... Air is clearly leaking/shooting (in time with the engine) right at the head gasket. I let the bike warm up a bit and gave it a few revs and puffs of white smoke escaped and I shut her down.

I waited until the next day and took off the top part of the cylinder and re-torqued everything to spec, no dice.

The only thing I can imagine I did wrong was I learned the hard way that my torque wrench was busted while tightening down the head screws, only did one and figured I had put way more torque on it than it called for before giving up and getting another wrench. So possibly I botched the new gasket?

Air is clearly coming out of the head gasket, between the top and bottom half of the front cylinder but could it be something else? I did not replace the valve seals. Could that be it? Would air/gusts of air/smoke (maybe even a little bit of oil) be coming out at the head gasket area if the valve seals are bad?

Sure would appreciate any thoughts on what to try next.

Thanks in advance,
Zack

 

Top of cyclider could be warped? Pulled stud that isn't holding are my first two thoughts

 

Maybe head idk, I've never had a warped head that leaked, but I've had cylinders bad enough they will blow a gasket then will not seal afterwards. Even with good quality comtetic metal gaskets

 

Sorry for all the post, the metal cosmetics would leak then seal up when hot. They didn't blow out, just sealed after the aluminum warmed up

 

Hi Madnss,

Thanks for the reply. Are you suggesting that I should perhaps let the bike run for a bit? That maybe the seals need to warm up before properly sealing?

 

No, mine would seal up with in 10 seconds. That's when I figured something was warped

 

Just a quick wrap up. The issue was all on me. I used Cometic parts but followed the HD shop manual and there are few things that you need to follow the Cometic documentation for. First the o-rings around the studs near the head gasket, you don't need those. Two, the torque on the head screws is way different. The shop manual for the bike tops out around 18-22 lbs or so but the Cometic guide tops at 42, pretty big difference.

Good news is that I was able to do the tear down and repair (I ended up using a new head gasket) in about 2 1/2 hours and the bike runs great.

Wonder if I should still consider running a compression test?