Yamahasrx700
Member
When ever mywife or daughter ride either my 97 SX 700 redhead or my 01 SXR 700 (dual bulbsled) redhead they both foul the pto cylinder plug. I have put on brand newplug caps that Ohm out correctly and changed the coils around on BOTH sleds.The carbs are clean. When I put in a new plug they go like hell again. I wouldaccept the “floats are sticking” or “the choke plunger is leaking” ECT but whatare the chances both sleds….
I would replace the main nozzle if it is still available. They wear out where the metering needle slides through it at the top. The main jet screws into the bottom of this part.
Yamahasrx700
Member
Ok. But both machines,same cylinder. The SX has 14 thousand miles and the SXR has 6 thousand.
Well, they are both jetted the same stock.
145 PTO
143.8 Center
143.8 Mag
All the 700 redheads we run, we straight jet to 142.5
However, we use the main jet, lol
where, as you may not as much (Wide open throttle)
Don't know why you would be fouling the same plug in both sleds.
I have not lost a plug in years.. But, I don't run the stock pig rich jetting either.
145 PTO
143.8 Center
143.8 Mag
All the 700 redheads we run, we straight jet to 142.5
However, we use the main jet, lol
where, as you may not as much (Wide open throttle)
Don't know why you would be fouling the same plug in both sleds.
I have not lost a plug in years.. But, I don't run the stock pig rich jetting either.
Yamahasrx700
Member
Both are bone stock.
Bone stock = pig rich lol
tell us how they are ridden ? a lot of half throttle ?
a lot of 15 mph ?
Yamahasrx700
Member
I guess my point is when I ride either sled it throttle to the bars and I don't have an issue. But everyone does not ride like me. Does everyone that has a 700 redhead foul plugs when they are just to tooling around looking at the scenery.
No, they don't, but redheads are know to be fat in the midrange (needles).
May be why you are not having problems, and other riders are.
May be why you are not having problems, and other riders are.
A couple of bucks
VIP Member
Drop the needle on the problem cyl.
Get those new main nozzles like I mentioned. They have to be installed from the top which means slides removed. Before you put the new ones in take a look at them side by side(new vs old) at the top hole(non-threaded end).
You'll be very surprised how much the hole is worn and oblonged. Lowering needle does nothing when this part is worn out.