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Bad petcock?

Posted: Thu Jun 19, 2008 8:01 pm
by starsnbars
I recently did a top-end rebuild on my 85 spree. The rings were replaced as well as all the appropriate gaskets to do so. I grinded out the intake with a dremel bit and drilled through I think 2 or 3 of the muffler baffles. I did a compression test and obtained around 122 psi. My carb has been completely cleaned out by hand, I'm running all the normal jets and carb settings. I haven't done a plug chop with a new plug, but the color of my fairly new one after driving with rebuilt top-end is a light brown/red. My tires are at the proper psi, the drive-belt is not worn down. and I weigh 160 lbs. SO... why am I still only getting about 28 mph on a good straight-away. The bike never bogs and accelerates amazing off the line. The muffler has been decarbonized many times. The only thing I know that's wrong is the petcock. When i took off the carb to replace the rings, the fuel line drained until the gas tank was empty, when I thought the petcock should only allow fuel to drain when vacuum is applied. With this bike I thought for sure I'd be getting something over 30, but no. I'll be getting a new petcock after the weekend, but could this be the problem? I don't understand how it could be if the bike runs great except for the low top end. If there's anything I should check please help me out, my speedometer is begging me to pass the 30 notch!!!!!

Posted: Thu Jun 19, 2008 8:20 pm
by CharlotteSpreeRider
How many miles since the top end rebuild? My bike seemed a bit slow after new rings, but after a while it got better.

-aseigler

Posted: Thu Jun 19, 2008 8:21 pm
by starsnbars
about 12 lol

Posted: Thu Jun 19, 2008 9:26 pm
by Kenny_McCormic
You gotta break the rings/re honed jug in (wear the hone marks of by running it) before the compression will come up and give you better power.

Posted: Thu Jun 19, 2008 10:13 pm
by starsnbars
Well my cylinder looked really good, no scoring or anything, so I didn't hone it. Will my compression go higher than 120? I thought that was the max.

Posted: Fri Jun 20, 2008 11:26 am
by Kenny_McCormic
120 sounds good, my spree only goes 28 and its the 86 with the higher performance top end.

Posted: Sun Aug 03, 2008 3:42 am
by brad_659
now im *...im mid full top end re-build and this sucks now that i know im going to be running slow for a while....ill just have to drive it more i guess!