backfiring, bogging, trouble starting

[T.K.]

My new to me 2008 Phazer mountain (6000 km) just started giving me trouble. after a hard days ride yesterday, on the way home it started backfiring, bucking/missing, stalling and then trouble starting. However it was only at low speed. at high throttle it was running great.

I'm not really sure where to start, but i read about the donut issue on the exhaust... because this is a common problem I thought I'd look there first... could this be the issue?

 

[YukonMP]

Since you mention a hard days ride and I know how much snow you guys have, it might be as simple as drying it out. If that does the trick you might want to go through all the electrical connections with dielectric grease. I forget what it is called but there is a sensor on the airbox that seems to catch guys out so it is worth a check.

There is lots on here to help you deal with the known issues for the 07 and 08 models so dig in!

 

[T.K.]

Drying it out is a great idea, and it cost nothing. that should have occurred to me lol. I am going to go ahead and replace the plugs. they may be the original and that shouldn't cost much either.

 

[Mooseman]

While you're there replacing the plugs, check that the coils are both firing. I had a bad coil and similar issues to yours.

 

[T.K.]

While you're there replacing the plugs, check that the coils are both firing. I had a bad coil and similar issues to yours.

Thanks, I'll look up how to check the coils now.

I'm well into it and it looks like I'm not the first guy in there. The bands for the donut gasket on the exhaust were not attached and it looks like they have already been cut down.

https://ibb.co/jvtJJwP
https://ibb.co/DkHDChD

 

[Mooseman]

Now's the perfect time to put in come copper donuts. Those look done.

Easy enough to check the coils. With them out and plugs in and touching ground, crank the engine. Or go into diagnostic mode and activate them in there.

 

[T.K.]

Now's the perfect time to put in come copper donuts. Those look done.

Easy enough to check the coils. With them out and plugs in and touching ground, crank the engine. Or go into diagnostic mode and activate them in there.

got the new donuts installed and everything all cleaned Up https://ibb.co/KyjnSvH

next up test the coils

 

[T.K.]

got the new donuts installed and everything all cleaned Up https://ibb.co/KyjnSvH

next up test the coils

ok, so I put coils through diagnose test on 30 and 31, heard all five sparks. Hooked up my little spark tester and ran test again. Saw spark 5 times on each coil.

took coils off, and tested on my multi meter:

9.3 and 9.5 Kohms on secondary resistance : within spec

But primary resistance is hard to read and all over the place 4.5 or 5.6 not sure if I should replace

 

[Mooseman]

Pull the rubber plug end cap and check the condition of plastic underneath. Mine was broken with rust stains. The rust can cause shorting. Cleanup everything and use dielectric grease.

In diag mode, you should also check the TPS sensor to be sure it's operating within range.

 

[T.K.]

Pull the rubber plug end cap and check the condition of plastic underneath. Mine was broken with rust stains. The rust can cause shorting. Cleanup everything and use dielectric grease.

In diag mode, you should also check the TPS sensor to be sure it's operating within range.

Stopped in to my local Yamaha check to see if they had any coils in stock which they didn’t. So these will have to do for the season. I cleaned them up, and I’m positive they’re getting spark.

I checked the diagnostic code is 01 throttle angle. Is that the one your referring too? If so it perfectly in limits 17-99

 

[Mooseman]

I checked the diagnostic code is 01 throttle angle. Is that the one your referring too? If so it perfectly in limits 17-99

Yes. And it looks to be in range.

 

[T.K.]

Got it all put back together and took it out for a run. Ride it hard for 10k , stopping intermittently to see what was happening at low rpms .... seems like it’s working great. Can’t thank you guys enough especially you mooseman. It might come back but I needed to do those repairs regardless. So it may have been cured by thawing out, fixing exhaust donut leak, new spark plugs or dielectric grease and cleaning on the coils.