2004 yamaha blaster bogs down and stalls when you mash the throttle

[blaster200mike]

Hey there this is my first post so bare with me lol. I got a 04 Yamaha blaster has tors delete and oil block off kit has a fresh top end and brand new cylinder,piston kit,also has a brand new carb and reeds. It starts and idles great and drives great if you feather the throttle but as soon as you try to get on it it bogs out and stalls but will fire right back up. Also it backfires through the exhaust when i try and keep it running by playing with the throttle. If I hit the throttle wide open really quick it bogs down but if I let off the throttle as soon as it bogs down it'll stay running if I play with the throttle any help would be great thanks also idk if it matters but the carb was bought off ebay and is a very cheap aftermarket carb but it says it's a mikuni stamped on the carb. Carb was put on by previous owner as well as the other stuff I mentioned also the top end kit he put on came complete with a new cylinder and top end kit it's from ebay and was only about $70.00 including the brand stock bore new cylinder

 

[Tooloose]

Hey there this is my first post so bare with me lol. I got a 04 Yamaha blaster has tors delete and oil block off kit has a fresh top end and brand new cylinder,piston kit,also has a brand new carb and reeds. It starts and idles great and drives great if you feather the throttle but as soon as you try to get on it it bogs out and stalls but will fire right back up. Also it backfires through the exhaust when i try and keep it running by playing with the throttle. If I hit the throttle wide open really quick it bogs down but if I let off the throttle as soon as it bogs down it'll stay running if I play with the throttle any help would be great thanks also idk if it matters but the carb was bought off ebay and is a very cheap aftermarket carb but it says it's a mikuni stamped on the carb. Carb was put on by previous owner as well as the other stuff I mentioned also the top end kit he put on came complete with a new cylinder and top end kit it's from ebay and was only about $70.00 including the brand stock bore new cylinder

Check for cracked reed pedals, if none found replace spark plug(b8es) ngk gap to factory specs. Retest if it still bogs, cut fuel off at petcock and drain carb bowl by drain screw and record amount. Could have improper float setting. Almost no fuel means float is set too low.

 

[blaster200mike]

Check for cracked reed pedals, if none found replace spark plug(b8es) ngk gap to factory specs. Retest if it still bogs, cut fuel off at petcock and drain carb bowl by drain screw and record amount. Could have improper float setting. Almost no fuel means float is set too low.

Reeds are good just replaced them and the carb is brand new on stock jets and air screw setting I heard that the crank seals could cause this

 

[Tooloose]

Reeds are good just replaced them and the carb is brand new on stock jets and air screw setting I heard that the crank seals could cause this

Do not rely on the factory to set the float right

 

[Tooloose]

Do not rely on the factory to set the float right

I chase this problem one time for almost a week and the spark plug was the actual culprit

 

[blaster200mike]

Changed the plug today no change. I forgot to mention that my blaster has dmc alien full exhaust and boyseen power reeds and the carb was bought off ebay it's a brand new mikuni which i assum has the stock jets and and stock needle postion and stock air/fuel screw setting

 

[04blasterdude]

Changed the plug today no change. I forgot to mention that my blaster has dmc alien full exhaust and boyseen power reeds and the carb was bought off ebay it's a brand new mikuni which i assum has the stock jets and and stock needle postion and stock air/fuel screw setting

Try to adjust the carb (air/fuel screw) and test it after that.

 

[04blasterdude]

Try to adjust the carb (air/fuel screw) and test it after that.

Also forgot to mention to get the right jets for your carb

 

[blaster200mike]

Also forgot to mention to get the right jets for your carb

What size jets and needle postion has brand new cylinder on stock bore with a stock size piston kit also has dmc alien exhaust and boyseen power reeds nothing crazy but with those minor mods what do yous recommend as far as jet sizes and the needle clip postion and how far out on the air screw

 

[Awk08]

Don't run that engine again with a stock jet and DMC exhaust, and hope you didn't damage anything already. It's very doubtful a carb off eBay has the correct jets for a blaster.
Even if it has a 230 main, it's way too lean for any aftermarket exhaust.

I think I'm seeing around a 280 main for that exhaust, and needle clip on 2nd position from bottom. Nobody can tell you exactly. Your results may vary at your elevation, temps and mods.

Should be a 32.5 pilot, airscrew @ 1.5 turns out to start
Try the needle clip move and buy a range of main jets.....270 thru 310.
Start large and plug chop down.

Find the threads in the carb section on..
float heights, pilot/airscrew tuning and how to plug chop, read, read again, and follow how to do it exactly.

Tune up....Float height, pilot/airscrew, needle, then main jet, in that order.

 

[04blasterdude]

What size jets and needle postion has brand new cylinder on stock bore with a stock size piston kit also has dmc alien exhaust and boyseen power reeds nothing crazy but with those minor mods what do yous recommend as far as jet sizes and the needle clip postion and how far out on the air screw

I have my blaster all stock besides full fmf exhaust and assuming you have the stock size carb (28pwk I think) you should try DMC and see if they say anything about it. If not go to fmf racing and go to the jetting center. If I remember correctly, fmf says main is 260 and pilot is 32.5 with stock needle and position 3 steps below top which is stock. After that, just play the the screw position or try 1.5 turns out to start and fine tune from there.

 

[04blasterdude]

What size jets and needle postion has brand new cylinder on stock bore with a stock size piston kit also has dmc alien exhaust and boyseen power reeds nothing crazy but with those minor mods what do yous recommend as far as jet sizes and the needle clip postion and how far out on the air screw

 

[Tooloose]

Hey if your running a hi performance exhaust system larger main jet size will be required to keep engine seize from occurring

 

[Tooloose]

Around 290-300 depending on humidity and ambient temps and riding habits

 

[04blasterdude]

Around 290-300 depending on humidity and ambient temps and riding habits

Actually if you look at the image I posted it says 260main, straight from DMC for the alien pipe, 32.5 pilot with stock needle, 5th position form top and 1.5 turns out on air/fuel screw.

 

[dirtysquared]

It says 260, but that is a probably at sea level and 75° and sunny. There are tons of thing that go into account for starting points, premixing fuel, air temps, elevation, air filter, airbox lid on or off..Etc.

Awk gave you the best general information above on starting points. Use that info, and plug chop untill you have it spot on.

I've ran DMC pipes for a long time. Dropping the needle one position is necessary. Depending on how much works done, and the more air you have moving through the motor it may like the richest clip position.

 

[Tooloose]

Take laser perometer and read the cylinder head temp approximately 850-900 degrees f.

 

[blaster200mike]

Ok thanks for the help guys I'll be messing with it tomorrow and trying those things. And would being to lean cause it to just bog out and stall. If I let off the the throttle when it bogs down it I'll stay running just finished building the quad everything motor wise is brand new except the bottom end and it's stock 66mm bore

 

[blaster200mike]

Hey guys update on my quad is no good still got nothing put a 280 main jet in checked reeds. The tors is unplugged and not on quad cause I got a aftermarket carb. I read somewhere about splicing wires together on the 2003-2006 yamaha blasters mines a 2004 so what wires and how do i bypass the tors system

 

[82cutty]

http://www.blasterforum.com/threads/03-06-tors-removal-diy.41973/