FYI- Sled won't pull over 6200rpm --something to look for

[Murph]

2016 AXYS ProRMK 163 3". Approx 820 miles (bought used with 619- thanks modit!)

Run on ethanol setting, one oz of oil per gallon added to fuel.

Warmed sled up at house. Filled fuel and oil.

Drove ten miles to staging area. Re-fired sled, unloaded off sled deck.

Sled was idling and coming up to operating temp as I was gearing up. Exhaust note changed and rpm dropped to 1400-1450.... Uh oh....

Jumped on sled and went to rip down road, full throttle, 6250 rpm.... Oh sh!t.....

Was thinking exhaust valves weren't opening. Figured I'd pull plugs and swap out.

Underneath plug caps had a ton of carbon soot on both. One plug golden brown, one significantly darker. Don't know if they were original plugs that went through break in mode or not.

Swapped plugs, rpm back to 8200, rode 50 miles no hiccups all day.

Got home and properly cleaned plug boot caps, spark plugs tops, and added dialectic grease.

My thought is the carbon build up under cap was allowing coil voltage to go to ground and not fire plug or not fire plug consistently. 6200 rpm is probably the max rpm for a 400cc single cylinder to pull with 800cc clutching.

Tested at house. New AXYS motor will start, idle, and power up mfd on one cylinder (pulled off one plug cap). New lighter crank is easier for one cylinder to turn over, unlike previous 800 motor that would drop to about 1200rpm and want to die.

 

[Murph]

Another of carbon soot on plug tops. I definitely wiped some off before I took photo. They were heavily covered.

 

[winter brew]

Reminds me a little of the '98 Summit-X issue.
Loose fitting plug caps would cause static that interfered with an inadequately shielded computer and caused a variety of running issues. New caps with dielectric silicone grease was the cure.

 

[Murph]

Hmmm....
Could also explain why some AXYS are noisier (RF interference) than others.

 

[winter4ever]

Looks like dirty caps from dielectric grease to me. and a fouled plug, probably more related to adding oil to the tank.

I did notice on mine when I checked the plugs that there is almost like two clicks when you put your caps back on. Thought I had it on and it clicked on one more time.

 

[Murph]

Looks like dirty caps from dielectric grease to me. and a fouled plug, probably more related to adding oil to the tank.

I did notice on mine when I checked the plugs that there is almost like two clicks when you put your caps back on. Thought I had it on and it clicked on one more time.

I would agree that the caps did not appear to be fully seated. Dirt ring on porcelain below cap indicates they weren't fully seated. No dialectric was present before, carbon buildup was totally dry.

As for 1oz, per gallon fouling a plug-- I'll disagree, been doing this for years with no fouling problems, even when I would 32:1 in the tank AND run oil injector when breaking in new motors.

 

[Red Mtn]

As for 1oz, per gallon fouling a plug-- I'll disagree, been doing this for years with no fouling problems, even when I would 32:1 in the tank AND run oil injector when breaking in new motors.

If you followed the instructions and added a qt of oil to the first tank in conjunction with the increased injected oil during initial break in I assure you, it can and did foul my plugs a few times, and I am not alone.

 

[Murph]

If you followed the instructions and added a qt of oil to the first tank in conjunction with the increased injected oil during initial break in I assure you, it can and did foul my plugs a few times, and I am not alone.

Absolutely agree with this. During the initial break in mode, the electronic oil injection is very rich. At 800 miles, I am well passed the increased oil injector output. As I stated in my first post, I am unaware if these are the original plugs or not since I bought the sled with 600 miles on it.

Now that I am out of break in mode, with new plugs, I am not particularly concerned about 1 oz per gallon fouling plugs going forward.

 

[diamonddave]

I would agree that the caps did not appear to be fully seated. Dirt ring on porcelain below cap indicates they weren't fully seated. No dialectric was present before, carbon buildup was totally dry.

As for 1oz, per gallon fouling a plug-- I'll disagree, been doing this for years with no fouling problems, even when I would 32:1 in the tank AND run oil injector when breaking in new motors.

Some of us, at least with the Pro motor, couldn't run as much as 1oz of oil per gallon with a 32:1 ratio without fouling plugs. More of an issue when in very cold temps.

I'm not doubting you have been able to do it without issue though. I could do it with CFI-4's.