I don’t get it, axys plug fouling

[MrIQR]

Axys 800, runs a like a rich pig, idles low. Always fouls one plug at a time, was the mag side yesterday, no way to predict what side will foul next, and will even foul on wide open pulls.

Tps set
Fresh top end
Full slp exhaust
Slp head

Ideas?

 

[509_Colton]

Fresh top end due to failure or preventative maintenance?

 

[A@ron]

Check plug wires?

 

[MrIQR]

Top end was preventative and it did it before then. It’s been doing it for years..

 

[MrIQR]

Fresh top end due to failure or preventative maintenance?

Top end was preventative and it did it before then. It’s been doing it for years..

 

[TDR]

I had an 18 that did this. Throttle Position Sensor. Took me almost 2 years to figure it out. Digital Wrench would say it was in spec but fouled like crazy. Changed TPS and set via good digital voltmeter and has worked perfect since then.

 

[MrIQR]

Check plug wires?

Can you explain to me how it would be the plug wires?

Imo You get spark or you don’t.

It runs rich, spark is not the issue, a extremely rich condition is.

 

[MrIQR]

I had an 18 that did this. Throttle Position Sensor. Took me almost 2 years to figure it out. Digital Wrench would say it was in spec but fouled like crazy. Changed TPS and set via good digital voltmeter and has worked perfect since then.

Are you saying replace the tps or reset it?

I’ve reset the tps numerous times, no improvement.

 

[Kylep]

Are you saying replace the tps or reset it?

I’ve reset the tps numerous times, no improvement.

My 17 did this basically every ride for awhile, changes plug wires and caps, swapped coils from a good sled, still happened frequently. Ended up trying br9eya plugs and they have been good for 2 years and 800ish miles. Lots of moving around the yard and not running it hard in the last year tho

 

[kanedog]

I feel your pain. It’s a very sad pain especially start of winter.

 

[MrIQR]

My 17 did this basically every ride for awhile, changes plug wires and caps, swapped coils from a good sled, still happened frequently. Ended up trying br9eya plugs and they have been good for 2 years and 800ish miles. Lots of moving around the yard and not running it hard in the last year tho

I forgot to mention I’m running hotter bpr8es plugs. It runs so rich there is a noticeable power loss throughout the whole rpm range and loss of peak rpm’s.

 

[RHODESIE]

do you have a fuel controller on it?

 

[MrIQR]

do you have a fuel controller on it?

no controller, the slp pipe/head doesn’t need one and it was just as rich before I installed them.

Runs so rich it stains my side panel and leaves turns snow brown.

But sometimes, like pictured one cylinder will run perfect then eventually go rich and foul.

Anyone put a set of tm-40’s carbs on?


Carbs > efi, you’ll never change my mind.

 

[mtncat1]

i would check the injectors

 

[RHODESIE]

would be interested to know what colour injectors are in it. different colours have different flow rates. is it possible its not mapped to the proper injector colour.

 

[TDR]

Are you saying replace the tps or reset it?

I’ve reset the tps numerous times, no improvement.

Replace it fixed both of my 18’s

 

[mtncat1]

if it's the same plug fouling every time i doubt a tps will help

 

[kanedog]

Party foul

 

[diamonddave]

Can you explain to me how it would be the plug wires?

Imo You get spark or you don’t.

It runs rich, spark is not the issue, a extremely rich condition is.

Your opinion of either getting spark or not is not real world true.

The coil pack, plug wires, spark plug caps are failing intermittently. It’s really difficult to tell when they blink out and come back. I’ve been replacing coil packs for about 3 years now for plug fouling issues. A few guys had it happen last year on 22’s.

There are many causes for this symptom. Injectors, worn or unseated rings, cylinders out, updated flashes, worn spark plug caps, coil packs, stators. It can be difficult to solve but don’t discount coil packs. They seem to be more common than some of the other causes.

 

[MrIQR]

Your opinion of either getting spark or not is not real world true.

The coil pack, plug wires, spark plug caps are failing intermittently. It’s really difficult to tell when they blink out and come back. I’ve been replacing coil packs for about 3 years now for plug fouling issues. A few guys had it happen last year on 22’s.

There are many causes for this symptom. Injectors, worn or unseated rings, cylinders out, updated flashes, worn spark plug caps, coil packs, stators. It can be difficult to solve but don’t discount coil packs. They seem to be more common than some of the other causes.

So coil packs can go bad intermittently? Or cause a overly rich condition? Pretty sure I’ve swapped coils twice. 3 different wiring harnesses. Tons of relys.

It always runs rich and idles low. It will foul plugs wfo sometimes other times it will do long pulls ok but doesn’t pull like it should. It’s not strong at all, has full slp stage 2 and fresh top end.