Fuel screw setting


So after riding last weekend i still have the low end bog. I know i said it was gone but its not. This is driving me nuts! I tried to find an airbox that was not modified on ebay but could not find one. So I bought the baffles cone for the top but can't get the dividers because the don't make them anymore. Would I be good to go with just the baffles cone or do I need the dividers too? Could this still be part of the low end bog? I read of people just doing main jet adjustments with a gutted airbox and that tells me if anything I would have a problem at WOT. What do you guys think?
 
if you put the top plate in with the holes that should help make it more consistant with the jetting, the early divider plates were eliminated by Yamaha in a couple years anyways, by 2000 the srx didn't use them in the box anymore just a baffle plate.
 
What rpm does it engage at? Maybe it's too low. I changed my v4 from 3600 to 5,000. No more bog. Two strokes don't really make much low end anyway
 
I wouldn't think it is the pilots. Not saying they wont help. It shouldn't bog even with the stock stuff. What happens if you choke it just a little while in the bog? Also how are the reeds?
 
I'm guessing since you said it had a crank issue when you got it the crank seals have been replaced. I haven't experienced bad reeds so I cant say what happens when they are bad but could be worth looking into.
 
mrviper700 said:
sorry but your mistaken, the screws are "fuel screws" as they are before the slide in the carb(engine side of carb), they meter fuel not air. If the screws are located behind the sled(airbox side of carb) then they are air screws. This is like this on all brands of snowmobiles. so on a yamaha snowmobile you turn the screws out from lightly seated to make the idle and low speed operation richer!
Click to expand...
I keep the two straight in my head by:
AIR screw is on AIRbox side.
 
Ok I still have the bog. Things I did this time around, checked the Reeds and found out one of the Reeds were turned with the concave side up witch should be the opposite so I ended up just buying a new set and installed them the right way. I thought I was on to something there but after getting it back together it still was the same. That did help with starting tho.so thend I put the baffles in the airbox that where never there and that never worked either. I went back to the 47.5 pilot jets because it sounded like I had a lean sneeze going and turned the fuel screws to 1 3/4. No more lean sneeze but still a bog. I checked to see if I was sucking air with starting fluid at the crank seals and the base of the block and the Reed boots. Oh and for the he'll of it I cleaned the carbs again. I was thinking float hight next maybe. I guess I should have checked it when I had the carbs out for the 10th time... what do you guys think?
 
Where is your belt riding in your secondary? The reason I ask is that I had a bog on my SX7 even after I spent many quality hours with her carbs. Couldn't get it to go away for nothing so I lived w/ it. I picked up a new belt to put on and moved the old belt to the "relief pitcher" position. Just by putting a new belt on got rid of what I though was a fuel bog. In all actually, whenever I mashed that throttle at a full stop was like taking off in 2nd or 3rd gear. It wasn't a fuel bog. It was a clutch problem masking itself as what I perceived as a fuel problem.
 
Last edited:
You must log in or register to reply here.


Back
Top