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Any guesses???

3672 Views 22 Replies 7 Participants Last post by  sfcmcgan
So.. My6 bike has a sever issue... I had to put it in the shop (Hinshaws motorcycle in Auburn).. it has the mech's baffled!!! Here are the symptoms:

1. rear cylinder has very little (i mean very little) exhaust. Kinda like when you breath fog on a window. the little it has gets very hot compared to the front cylinder. make a wierd "Psst, Psst Psst sound at idle.
2. engine light does NOT illuminate. But the fuel meter seems to be stuck at full bars even though I have less than a 1/4 tank fuel... this could be a different issue...not sure.
3. Rear cylinder has good compression... good spark.
4. using the Diagnostic mode... both injectors check out as good.
5. both cylinder run at approx 10 degrees diffrent from eachother... 201 -211.. these flux slightly... but nothing out of the ordinary. ( side note... if you measure either front or rear temps just below the plastic chrome covers... 1 side will be way warmer than the other... just FYI)
6. The bike still produces power and is totally ridable. there is power loss, but I could hit 60 fairly hassle free.
7. Gas is good (someone would ask)... drained all the fuel and replaced with fresh gas.
8. there is no strange internal sounds. Used a stethescope and listened.
9. there is no smoke coming out the oil filler hole... nor is there water in the oil.
10. no backfiring of any kind either thru the exhaust or intake.

Last thing... I completely disconnected the Cobra powerpro tuner and hooked up the stock config (much easier the 3rd time)... same issue...

My diagnoses is a bad fuel injector (I pray that is what it is!!!), but nobody at the shop had ever seen this particular issue.... I will let everyone know when I do... but your opinions are welcome!!!
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Straightjacket said:
It's really hard to troubleshoot without seeing the bike and being the one testing it. Knowing what the mech. has actually done? With that being said and how new the bike is, I would definately check the pipe for an ubstruction. A friends kid was trying to help him work on the bike by putting tools in his pipe, you never know? Someone else mentioned a broken baffle, I think it was the same pipes? You said you had spark, but is it at the right time? Or all the time? Maybe a bad pick up coil? Someone else also mentioned the coil wire on the rear cylinder being loose?
I don't think you would have a higher exhaust temp on that cylinder if it was a spark or fuel issue. Sounds like exhaust valve not opening (there are two per cylinder) or timing.
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