[stevpaw]

I've been working the bugs out of a 94 Mach Z I bought this year. That last problem was leaking oil lines. I fixed this with new washers. It runs great now, however I keep fouling plugs in the one cylinder on the MAG side. It has the 400 jet in it and I was thinking of jetting down to 390 or 380.
Also I was wondering if maybe the oil pump applies more pressure to the first line so this cylinder may get more oil than it should.
Could also play with the air screw a bit to lean it out at idle.
Anyone else experience this problem? Any suggestions?
Thanks.

 

[Doo fixer]

In 94 all 3 cyl. were jetted diff. easily go 2 sizes down.

 

[dino]

stevpaw Don,t mess with the jetting as they are very close at -15c or less. When does it foul? Dino

 

[stevpaw]

Dino,
I had it out the other night after fixing the oil leak. It ran fine then the next morning when I fired it up after about three pulls the  Mag Cyclnder back fired and started missing. I check the plug and it was heavily carboned up. I was wondering if the oil pump might be stronger on this cylinder. Also, the other cylinders are running a little rich as well now. I thought I could go down to 370s on those cylinders and 380 on the MAG cylinder. But like you said, I have heard it best not to play with the jetting on the Mach Z. I could adjust the air screw on the MAg cyclinder and see if this clears things up. it may be fouling up when its idleing.

Any suggestions? I don't want to keep changing plugs..
Thanks in advance Dino, so far your advice has been a big help.

Steve

 

[dino]

stevpaw: Does your sled have a primer or enrichment valve? I had fouling at trail speeds, mostly after stopping on trail and on restarts it would foul the mag or centre plug. I installed Bosch W2CS @.018 gap and have had no problems for three years now, and still the same plugs. Dino

 

[stevpaw]

Dino, there's no primer, just the enrichment valve. I haven't had the opportunity to ride much so not sure what is causing the problem. I found an older message of yours o nthe board with the proper settings for these carbs - 380-370-380 plus pilot settnga nd air screw settings. So I will start from scratch and check that all is correct before I go any further. One shop recommended going to the NGK BR8ES plugs to get a better burn. Do you agree?

On another note, I think I heard a Crank Bearing rattle on the MAG side when I hit the kill switch today. Not too happy about that. Looks Like
I might be tearing her down after all.

Steve

 

[stevpaw]

Good News! It'snmot a bearing problem. It's the water pump. Waiting for parts, should have it bck up and running Friday night. Then I can test the carb adjustments I've made. Will provide an update next week.