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Discussion Starter #1
I have 1500 miles on my F7 SP. I like the machine & am getting to know it pretty well. I have noticed a knock that occurs when cruising in the 5800-6200 RPM range. It seems to occur when lightly squeezing the throttle from this range. Sounds like detonation or spark knock. I have called the dealer & scheduled some of their time to look at it. Before I drop it off I am going to try higher octane fuel. I have been running 87 with a splash of iso. I recall Spaulding saying 87 should be fine. Has anyone else heard such a noise? I'll keep everyone posted.
 

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AC is recalling the ECU's on certain sleds (with certain fuel tolerances) due to a lean condition at lower to mid RPM's and also a coolant temperature mapping changes on the ECU. They are having problems with seizures right in this RPM range, so this may be your problem?
 

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This may sound crazy, but a very knowledgeable friend of mine who has ridden and raced Cats for years has a theory on his F7 mag side seizure. The cylinders had lots of flashing (extra material from casting) in the intake ports and it is possible that when the engine gets hot, the flashing can get so hot that it acts like a spark plug and can pre-ignite the fuel before it enters the combustion chamber. That could certainly cause a piston to overheat and seize! He is machining the flashing out of the intake ports.
 

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Check the main exhaust pipe heat shield clamps. After about 1000 miles on my F7, I noticed an unusual fast, rattle/ticking sound coming from somewhere under the hood, that seems to be getting progressively worse. Didn't seem to be drivetrain related, but rather, like it could be engine or clutch related.

I'm 99% sure I've found the source of this noise. I'll know after tomorrow's ride for sure. Seems like the exhaust shield clamps are loosening up after getting some miles on these sleds, just enough to make the rattling/ticking sound I've been hearing. The first clamp, nearest the y-pipe, was loosest on mine. I could hear the noise at idle too, especially at around 2200-2500 RPM, and when I tightly grasped the heat shield near that clamp (with a COLD exhaust of course!!!) the noise went away! I cut off that clamp (tough stuff!) and put on a conventional type hose clamp. I'm sure it's just a matter of time before the other two heat shield clamps will have to be replaced as well. -- Roy
 

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Discussion Starter #6
Thanks Roy - I'll check that this evening.
 

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Put 100 miles on today, and as suspected in my above post, replacing the loose exhaust shield clamp with an adjustable hose clamp eliminated the noise I was hearing. Much better now!

On a related note, the recoil handle will sometimes rattle too against the plastic cowling. -- Roy
 

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Discussion Starter #8
I tried 94 octane this weekend. The noise is still present albeit a little quieter. I am dropping it off tonight. I also have the noise coming from the exhaust shield - probably will end up with teh rad clamps.
 

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Discussion Starter #9
My dealer called today! They feel the noise I am hearing is the exhaust shield not spark knock. They are replacing the entire pipe assembly :eek: . I said it would be fine if they replaced the stainless clamps with stainless radiator clamps. He said that was an unacceptable fix for an 8000 dollar machine. So the new pipe will be in tomorrow. Seems a little extreme, but I will be happy for another 1800 miles and then it will start making that noise again :D .
 

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Originally posted by bilbat@Feb 11 2003, 04:57 PM
They are replacing the entire pipe assembly :eek: . I said it would be fine if they replaced the stainless clamps with stainless radiator clamps. He said that was an unacceptable fix for an 8000 dollar machine. So the new pipe will be in tomorrow. Seems a little extreme, but I will be happy for another 1800 miles and then it will start making that noise again :D .
Gosh, sounds kinda' extreme to me too. Talk about goin' overboard to fix your problem! For anyone else out there with noisy exhaust shields -- which will likely be EVERYONE after a while -- the hose clamp is working just fine and can be tightened up later if needed! -- Roy
 

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Discussion Starter #12
Where did it break? It would be useful so we know where to look for the failure.
 
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