Compression Test Failure

[GTO MIKE]

Actually just read where fuels with some ethanol  added are great at at cleaning the valves and combustion chamber . Most fuels have up to 10% ethanol with Yamaha says if fine to run in their bikes.   Mike

[Ride365]

Should be less corn juice in high test, should there not?

[RaYzerman]

Generally speaking, one should run TopTier fuel as it has the best additive package for keeping things clean.  Premium fuel may or may not have 10% ethanol, check with your local station....  very soon (here) we will not be able to get ethanol-free any longer.  Controversial whether ethanol actually helps, some say ethanol causes problems, so check your facts.... 

What happens to some is sticky deposits build up on the intake valve stems, presumably on non-TopTier fuels or short trips where things don't get to extended times at full operating temperatures.  This will cause the valves to stick once the engine cools down.  If a valve gets stuck open, may be hard to start.  You'd have to remove your throttle bodies to see if that's the case. 

Otherwise, short trips and not using the engine's horsepower band may carbon up the intakes at the valve seats, whereas the exhausts run hotter.  Piston tops will build carbon eventually as well.

I'd sure like a better explanation from the dealer or Yamaha on the bad fuel determination..... did they test the fuel or just what specifically did they mean by that......

https://en.wikipedia.org/wiki/Top_Tier_Detergent_Gasoline

https://www.toptiergas.com/gasoline-brands/

[betoney]

32 minutes ago, Ride365 said:

Should be less corn juice in high test, should there not?

10% ethanol is still 10% regardless of octane rating. 

I usually use premium (91 octane here) Shell, Chevron or Exxon and the pump usually advertises detergents or cleaning agents. 

In the cold months when I ride less and the bike sits more often, I use Non-Ethanol or E0 but its always a no-name brand fuel and there is never any mention of additives or cleaning agents, though I have no clue whether those detergents actually do anything for carbon build-up.

[bwringer]

I'm glad the OP has his bike back and all is well, but the "bad gas" story still doesn't add up.

There's a multi-step game of telephone going on here, not least of which is that the OP was not able to talk to the tech directly. Seems very, very odd that there are no pictures of the parts; for one, I'd imagine Yamaha would need this evidence to approve that much warranty work.

Ah well, the bike is fine, so all's well that ends well.

But the internet rabble hereabouts sure would like to know what the hell actually happened so we can make sure it doesn't happen to our bikes. I don't suppose we'll ever find out.

Edited November 27, 2023 by bwringer

[RaYzerman]

100% agree, the story doesn't add up, and no good pictures..... I'd sure like to know the real answer....

[skipperT]

The ‘real’ answer given to the OP was carbon build-up resulting in compression loss and a no-start condition. 
This is legitimate potential failure.

What caused it has been speculated about quite a bit here. The shop who performed the work may have another idea than ‘bad gas’ and are trying to go easy on the OP or save face themselves. or they might not have a clue at all and can only explain the build-up they found in the engine with that phrase.
Service writers also don’t always understand what techs are getting at either when they are provided an explanation, it’s kinda like the telephone game you played when you were a kid. 

-Skip
 

Edited November 28, 2023 by skipperT

[bwringer]

Just to be safe, I'll continue to make sure I take my FJ-09 to lots of places far away so I can buy gas from a wide variety of outlets, plus I'll make sure and use the entire rev range on a regular basis.

You know, all for maintenance and reliability reasons...

[Mike A]

Finally got my tracer out for a good ride yesterday, 175 miles or so.  I noticed a significant improvement from when I last rode it (Labor Day).  Of course after that long abstinence, it had to feel good.  The bike ran flawlessly.  I called my dealer service advisor this am to thank him and again ask about the culprit.  From the onset, they thought it was all about the carbon buildup.  Once the head was rebuilt, carbon removed, assembled they found no issues.  So why the carbon build up?  Bad gas was the standby answer!  I have to go with that and be a little more diligent about where I buy gas, maybe add an additive, and definitely run the revs higher!!!  Thanks for all of the input.

[Lone Wolf]

5 hours ago, Mike A said:

So why the carbon build up?  Bad gas was the standby answer! 

If they 100% believe that - it is hard to fathom that they warrantied the repair.

If Yamaha had "0" fault, it wouldn't be a warranty claim. 

But, it may be one of those rare good faith decisions based on your long relationship with dealer.

[RaYzerman]

I'm having a tough time believing anything "bad gas".... we are allowed anything up to 10% ethanol and there is no requirement to use "Top Tier" gas.... however, might be advisable if you did.  I suspect it was warrantied because you had extended warranty..... what we don't know is how it got carbonned up, but if you can, help us understand how you ride this bike, commute, etc. and maybe we can make a little more sense of the "bad gas" thing.  What was bad about it?

[1moreroad]

FWIW I have 48k miles on a 2015. I do a LOT of commuting (this year 100% of my mileage ), rarely hit 7k rpms commuting, and rarely get to redline period with no issues. I didn't buy the run your engine hard requirement. It might be better to use the whole rev range but I don't think it's a requirement. 

I always run 91 unless they run out. 

[OZVFR]

I haven’t read the entire thread, but it could have been caused by incorrectly adjusted intake valves from the factory, or got too tight before adjustment time. 
I definitely don’t buy the bad fuel story. 

Edited December 3, 2023 by OZVFR

[Mike A]

I don't feel that I baby my Tracer at all, however, compared to my younger days I do.  I run it up in the revs because I like to, but never sustained. I'm a much slower rider than I used to be.  Age will do that to you.  I don't think the lack of running the bike harder or using more revs is really the factor on a modern motorcycle.  That said, my Dealer blames 'bad gas".  They decarboned it, put it back together and it runs perfectly.  He tells me to stay away from that gas station and to use an additive when I can.  So that is what I am going to do.  I can't explain how extended warranty covers that, but they did!  I am running the revs higher because my simple mind is telling me to. I'll be the first to say it all seems strange.  I don't have any other answers..

[KrustyKush]

I had a 1997 Royal Star.  At 25k miles I did the first valve adjustment check.  One intake valve was so tight even my .0015 feeler wouldn't enter the gap.  I learned from that bike to do a first valve clearance check a bit early.  On my 2021 Tracer, I checked my valves at 12k miles.  Both exhaust valves on #3 were a hair under minimum clearance.  I adjusted them.

Somebody suggested valves may have been tight from the factory.  Yeah, I believe that is possible!