750 smoking a lot

Waternut

Customizing addict
Location
Macon, GA
I'm running premix of 50:1 in my 750sx. I don't really understand why it smokes like a mosuito truck. I understand all 2 strokes smoke some but this is a little excessive and if I turn around while idling I can see a light cloud of smoke behind me. I've tried using different oils with no luck. When I use premium fuel it lessens the amount of smoke but it's still there. Any ideas of why it's doing this? Compression is good on both cylinders.
 

Waternut

Customizing addict
Location
Macon, GA
I've tried Quiksilver synthetic blend for outboards and Pennzoil marine synthetic. There are no boat shops around here really so I haven't found any kind of quality pwc oil anywhere.
 

WFO Speedracer

A lifetime ban is like a lifetime warranty !
Location
Alabama
Anything made for an outboard is goaing to smoke like crazy,try something like Torco smokeless oil,Maxima marine pro or Klotz
 

tor*p*do

Squarenose FTW
Site Supporter
Location
NW NC
I run quicksilver and it doesnt smoke much at all!
Checkm you plugs- they may fouled
 
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Waternut

Customizing addict
Location
Macon, GA
It does it even with brand new plugs. What's a good place to order some of that smokeless oil? I can't really buy any locally that I know of.
 

demolition_x

Not After Fame & Fortune
are you sure the carbs are tuned right?

im running pennzoil and it doesn't smoke bad at all.

what do the new plugs look like after you have romped on the ski for a little?

they should be a brown color and dry, if they are black and wet your running rich.
 

Waternut

Customizing addict
Location
Macon, GA
Well I'll be honest and I don't think the carb is tuned properly but after 2 hours of riding I can't really tell much from the plugs. When I remove the plugs there is black oil on the threads and on the seat of the plug and head. However, when I look at the plug it's still shiny silver on the base. Now here's where it goes from wierd to wierder... The side electrode is near black (with a wet look) up to the bend and from the bend to the tip it's brown and dry. To me that means it's lean and rich...Is that possible? I've tried taking many pictures and they all come out blurry.
 

njfl

X-H2
I'm running premix of 50:1 in my 750sx. I don't really understand why it smokes like a mosuito truck. I understand all 2 strokes smoke some but this is a little excessive and if I turn around while idling I can see a light cloud of smoke behind me. I've tried using different oils with no luck. When I use premium fuel it lessens the amount of smoke but it's still there. Any ideas of why it's doing this? Compression is good on both cylinders.

Double-check you rcalculations. How much oil do you add to a 5 gallon can? Most oils end up with 16 ounces per 5 gallons giving 40:1, so considering that, I would expect you to be adding roughly 12 ounces per 5 gallons of fuel.

Don't jump and buy smokeless oil. You have some other problem/situation that you will just be masking and you will never achieve optimal performance.
 

tor*p*do

Squarenose FTW
Site Supporter
Location
NW NC
try the patch . . . . .that helps most of them quit smoking!


Sounds really rich from your observations- take pix of you plugs and post them.
Is the ski stock? I am running 1 1/8 hi speed, 1 1/16 lo speed with stock motor and pipe - only R&D f/a to replace the broken up stock airbox
 

Waternut

Customizing addict
Location
Macon, GA
I usually put 5.5 gallons in the can per the pumps calculations and then add all but 2 ounces from my pint (16oz.) of oil. That's easiest even numbered 50:1 ratio for me.
 

tor*p*do

Squarenose FTW
Site Supporter
Location
NW NC
was the carb re-jetted with the add of the FP?
Or did you just back out the mix screws to try to compensate?
 

Waternut

Customizing addict
Location
Macon, GA
This is probably the most accurate blurry picture. This auto focus camera can't figure this out. This is after they've had the excess oil wiped off the threads. You might be able to see that the bottom threads are dark and the side electrode is dark but the base is clean as new.

im000018.jpg
 

Waternut

Customizing addict
Location
Macon, GA
The carb has been rejetted to factory pipe recommendations. I plan to order a brand new pop off spring soon but currently I'm using the best spring from the rebuild kit but unsure what weight it is.
 

tor*p*do

Squarenose FTW
Site Supporter
Location
NW NC
I am running the middle spring from my rebuild kit (~9 mm) and it runs fine
but, that is with the stock pipe
 
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