Blaster only run without airfilter

[jiggisblaster]

Hello, my Name is Igor and im from Germany.
I found this forum and must say i love it.
A lot of Helpful tipps are here.
Here in Germany dont exist a such large community about Blaster riders.
Please dont kill me if my English are not perfect but i hope you guys can help me out about my Blaster.

I have bought a 1999 Yamaha Blaster a few weeks ago.
The Blaster wasnt running so i have checkt the engine.
The Cylinder was completly damaged so i replaced it.
It was a no Name cylinder from ebay.
I have also cleand the Carb and deleted the tors System and made the electrical system new.
The Reeds was in good condition.

So i have mixed the fuel 1L:35ml and start the engine.
The engine runs and i can drive it but here is my Problem:


When i take the air Filter Lid off the bike runns Perfect.
I can clearly accelerate and everything is just perfect.

When the airbox lid is on it runs too,but realy bad.
When i pull the choke out the Motor dont run!
The Engine runs so like it becomes to much gasoline.
The Sparkplug is wet and the motor has no power.
When the bike stand in neutral, i can rev it up, but when i set the first gear and want to ride it
it has no power.

What can be here the issue?
I have cleand the carb, i have the float hight on 21mm. the carb needle is on the mid.
The Air/Fuel screw is set right. Spark plug is new. Air Filter is New.
The Blaster is completly stock.
The Main jet is 230mm.

I dont know what to do more and i hope you guy can help me out .

Thank you Guys

 

[Larry's Shee]

Is the filter clean? What mods do you have? What main jet is in the carb?

 

[jiggisblaster]

The Main Jet is a 230. The Filter is New. And the Blaster is completly stock.

Yesterday I tried some more gasset. I have taken the gascarated needle at the highest point in order to reduce the gasoline supply with semi-gas. At least I thought. With this setting I drove for a few minutes. The engine does not turn up. When I took out the ignition candle after the test drive it was damp and black. That means the cylinder still gets too much fuel. The only option I have now would be to downsize the main nozzle, right? Are there any other adjustment options on the carburetor to reduce the gasoline supply ?

 

[Slydog]

Are you running a foam filter? Or a kn style.
The Chinese version of the kn filter people have had the same problem you have described.
Put on a quality foam filter and try it

 

[Larry's Shee]

The Main Jet is a 230. The Filter is New. And the Blaster is completly stock.

Yesterday I tried some more gasset. I have taken the gascarated needle at the highest point in order to reduce the gasoline supply with semi-gas. At least I thought. With this setting I drove for a few minutes. The engine does not turn up. When I took out the ignition candle after the test drive it was damp and black. That means the cylinder still gets too much fuel. The only option I have now would be to downsize the main nozzle, right? Are there any other adjustment options on the carburetor to reduce the gasoline supply ?

You’re going about it the wrong way in your problem, and tuning

 

[Larry's Shee]

What air filter are you using? Did you oil it?

Is English your first language?

 

[jiggisblaster]

Hello guys, first of all thanks for your help. The problem has been eliminated. I found out that the float valve was defective. So there was always new fuel in the carburetor even though it was already full. I bought a carburetor repair kit and installed it. It's going reasonably well now, but I think it's a little underperforming. I still have the problem that at full throttle it does not have its full power. If I keep the gas tap at about 90-95%, it accelerates cleanly. I suspect she's still getting too much gas. What I also discovered is that the previous owner drilled 5-6 10mm holes in the air filter cover. I have already tested a 240, 250, 260 main jet, but it has even less power. By the way, the air filter is a new, original foam filter, I haven't oiled it yet, what kind of oil can you use there? Here are some pictures of the spark plug from the last trip. To me it looks like she's running too lean. What do you all mean?

 

[Slydog]

Glad you got it figured out.
Time to have some fun