While flushing my ski yesterday ('02 gpr), I noticed that while standing at the rear, there was a powerful rich-smelling exhaust. On a car, I'd be concerned. Is this normal on an idling ski on land?

Spark plugs seem OK. A little dark, maybe, but not wet. I've added D-plate and free flow, which I understood would lean it out a little. Carbs are untouched.

That's what you get for riding without me yesterday. I had someone pull your plugs and shove baby mice in. Would of used gerbils but they were all at Richard Gere's house.

Anyone with a serious answer?

You are taking a chance by doing this.

Re-jetting or re-adjustng the carbs is critical.

Fercho-

I don't understand - taking a chance on doing what? Not adjusting the carbs? If the ski runs rich from the factory, and it seems to be running rich after the free flow and D-plate, what gives? I thought these parts would bring the mixture more in line with what it ought to be. Why is it still running rich?

I am not sure who told you that the ski runs rich from factory. The only way to determine this is by by properly tunning the carbs. You think that you may have lean out on top but you lean it out thru the entire power band. When flushing the ski if you run it at idle you are actually feeding from a 95 Pilot. Also when flushing it you are not putting load on the engine so it is obvious tht under those conditions you are feeding more fuel than needed, but once you put load on the engine it is automatically leaned out.

This is the frist time that I heard of carb tunning by smell!!!

Plug chop does not really mean much. The only way to really determine this is by tach readings and piston wash.

If you do a plug chop it needs to be done inmediately after a WOT run

The answer to your question is the thing is just fine! It's a 2 stroke and they stink. It's like all 2 stroke lawn mowers. They stink and smoke badly. Does your ski run well in the water? If so then everything is fine.

Fercho- thanks for the info. I hadn't thought of the load/no load situation. It still doesn't explain why the ski is suddenly doing this, though.

By the way, exhaust smell is a very valid way to determine if a car is running rich. Sounds like it doesn't apply to skis.

David FYI European GP1200R which have a d-plate from factory come jetted with 92.5 pilots and 135 mains. OUt have a 95 Piulot and 117.5 main. Only because the D-plate makes the ski run so much cooler leaning out the mixture. Every other part is identical except for the CDI and Gauge meter

I think that the curve is the same. It is different because it does not monitor the cat con. Othe than that it is probably the same

It is not about back pressure. It is about dropping engine compartment temperatures which lean out the ski!!!!!!

There is a reason why Yamaha runs a richer jetting in non-cat units.

What is a C-plate ? Never heard of it.

The C Plate is totally open, the D Plate is not. You are looking at different back pressure. The D simulates the cat con and has the same pressure, the C is more open an requires jetting and carb tuning.