Blaster is puffing white and bogging

B

BlastrMastr240

New Member
Jul 12, 2011
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Hey, I got a 1989 Yamaha Blaster bored to 240- Vforce reeds- mikuni carb- K&N airbox- oil blockoff- and Kenda Klaw MTX tires..... Problem is the other day i was riding it and it stalled while idle after riding. I was in the driveway and kicked it about 10 times before it started again, and the only reason its started is because i cracked the throttle, when i floored it it felt like it was just idling and then it revved a bit and a huge cloud of black smoke poured out the exauhst real fast and it ran fine...... Next day I was riding and she stopped dead in the yard, would not run at all. Tried popstarting it... nothing, clean plug, nothing, air out the cylinder to ensure no flooding, nothing, finally it just..... started on a kick and and where the exauhst and the pipe meet (with the rubber gasket right next to your right leg) it spat BLACK oil onto the fender and out the pipe for just a seccond and ran fine...... :o Today, it runns fine exept white smoke out the pipe that smells like gasoilene and only gas, when idling cold if you just tap the throttle it stalls but if you crack it it revs. (the exauhst smells nothing like the gross tranny oil)

sidenote- The carb has a tube comeing out of the bottom of the bowl and looks like an overflow, and if the fuel line is open and the tube is pointing down, it dripps gas almost constantly. :-/
 
Ya, Im not exactly up for taking anything more apart on that bike. It runs after its been sitting for a bit, maybe I can get some guy to buy it :P But I realy thing its the crank case gaskets that could be busted letting oil into the cylinder :( this realy sucks
 
Mostly because black oil dripps from the silencer and that gasket around the expansion exaust chamber was spitting raw oil after it stalled. The white exaust smoke smells like gasoline, sure, but there is still wet oil running off the tip of the pipe. I guess i could clean the carb, no big deal, but I cant reason why it wont start, then when it does it make 1 big puff of black smoke, then just stays between pure white like steam and grey from the oil mix. (Using Valvoline 2stroke, Just bought Castrol super 2stroke oil).
 
that isn't really the greatest of two stroke oils but I the oil coming out of the exhaust is probably just black because of carbon in it. my oil comes out there too and it's black.
 
I would take the carb off and give it a really good cleaning and examination, chances are you just have something unwanted in there.

If you have a drain plug for the bottom end (some 2t's have this) drain it and see what has collected.

Do a leakdown test!

Check compression.

Do you mix your gas?

What mixture are you running?
 
1 problem with premixing that people don't often think about is that over time the oil and petrol seperate so u should give ur fuel a shake or stur it in some way
 
Ok, I got it running for the 1st time in about 12 hours of.... trying. I cranked it for about 10 minutes with the sparkplug OFF so it would air out. Then it ran like a charm, still a LOT of white smoke. And my unlcle (Mechanic) says its running lean, which explains the extreme bogging at low RPM. It does this: Idleing... rev it to go in 1st gear, but it feels like there is no gas, full throttle to compensate, and holding at full it feels like 1500 rpm, crack it a few times and it comes back to life, it does this almost EVERY time you lower the rpm just a little low, if it stalls, its EXTREMELY hard to start the motor again. Uncle says its lean with too much air.

The fuel was put in yesterday (premix at 32:1 (4oz Per 1 Gal(Shaken well))).

Carb is not dirty as far as I can see, but I also dont know how to tune this one..... :-/

It does run and still has great power at about 5000 rpm and can still pull the tires every time i crack the throttle in any gear as long as im at about 5000 rpm (estimate).
 
BlastrMastr240 said:
Ok, I got it running for the 1st time in about 12 hours of.... trying. I cranked it for about 10 minutes with the sparkplug OFF so it would air out. Then it ran like a charm, still a LOT of white smoke. And my unlcle (Mechanic) says its running lean, which explains the extreme bogging at low RPM. It does this: Idleing... rev it to go in 1st gear, but it feels like there is no gas, full throttle to compensate, and holding at full it feels like 1500 rpm, crack it a few times and it comes back to life, it does this almost EVERY time you lower the rpm just a little low, if it stalls, its EXTREMELY hard to start the motor again. Uncle says its lean with too much air.

The fuel was put in yesterday (premix at 32:1 (4oz Per 1 Gal(Shaken well))).

Carb is not dirty as far as I can see, but I also dont know how to tune this one..... :-/

It does run and still has great power at about 5000 rpm and can still pull the tires every time i crack the throttle in any gear as long as im at about 5000 rpm (estimate).
Click to expand...

If your uncle says it's Lean then do a compression check, if you are having this much trouble from running lean you have probably lost your compression and need a new top end.

It sounds like it's extremely Rich, do a little research and figure out if it's a "Lean Bog" or a "Rich Bog". Another reason I think it's rich is the oil from the exhaust that you described and the "white smoke". Normally White smoke means your head is leaking antifreeze into your engine but you don't have to worry about that with a blaster.

Whether it's Lean or Rich, it means your Carb is Dirty!

It wouldn't take you 30 minutes to do a compression check and thoroughly clean the carburetor, get on that and report back.
 
if the its not running and i put it in 2nd gear, it will not let the tires spin, does that mean good compression per chance?
 
I figured out it will take me a while to get that carb off....... and i have nothing to clean it with. Im out of state with it and dont have most of my stuff XP
 
BlastrMastr240 said:
if the its not running and i put it in 2nd gear, it will not let the tires spin, does that mean good compression per chance?
Click to expand...

Go to your nearest auto store, for instance in Kansas I would go to autozone or o'reileys and Rent a compression checker. Thread the compression tester into your spark plug hole and kick the blaster over until the needle will go no higher. Then return the compression tester and get all of your money back (except the tax you paid)
 
Ok, I have narrowed it down to tuning now (I hope), and I still need to buy some carb cleaner just to be sure, maybe something that i can pour into the fuel to clean it all out. Still blows white smoke almost as white as steam, and when I lightly tap the throttle (like barely touch it) it wants to stall but sounds like its sucking a lot of air in. I still dont know how to tune this carb, there are like no screws on it at all..... :-/ But it runs now, rides and im stummped on the white smoke that smells like regular gasoline. (I smelled the tranny fluid, gross XP )
 
While something like Seafoam may be good for getting residue out, it will not remove anything solid. All it takes is a screwdriver to pull carb and take float bowl off. Look for dirt or debrie in bowl. If you can take main and pilot jet out to be sure they are clear/clean. Even with that I still don't know if I'd ride it with the smoke issue. What kind of oil are you running? If trans smells bad it's probably time for a change. Is it low now?
 
I currently cant see oil in the tranny case, i take the little cap of with the 2 handles at the top and can see a gear or 2 but i see no oil, tho the gears are oily and lubricated. In the bike i use 2stroke oil from castrol, and before was valvoline 2stroke oil and both smoked as of 4 days ago. But..... what burns as white as steam but remains in the air for a long time, it will trail this white smoke for about 50 feet behind me when i ride it around the yard, but its WHITE! :-/
 
There is a little "window"/sight glass just below the kick start. You should be able to see the oil level in it, if not add to it.
I would highly suggest doing a leak-down test when you get back.
 
dscn5793.jpg

Does this carb look right to you? :-/
dscn5792.jpg


dscn5794.jpg
 
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