Yamaha Blaster Bogging Down

[edgarchavez]

Hello,

So my 97 blaster has been running fine for the past 6+ months but today when I tried to go out it started to bog out on me. I put in fresh gas mixed 40:1 with amsoil dominator and I also just cleaned the air filter. I checked the air screw its its 1.5 turns out. It had just been rebuilt about 9 months ago and I put in new gaskets about 6 months ago. It revs pretty cleanly up to about half throttle but after that it begins to bog down. What else should I check?

Thanks

 

[Gibbo]

I had the exact same problem I couldn't figure it out . I had just installed new cylinder piston reeds and all it could really be was the carb. I orderd a new carb and sure enough that sorted it

 

[Blaaster]

Is the weather temperature warming up, you may need to do a plug chop to confirm the jetting is correct.

The air screw is not a set and forget, it may need small adjustments as conditions change.

1.5 turns out is where you start to set the idle speed.

Idle speed adjusting.
Set float level, make sure that all jets are clean and fuel flows freely from the float bowl drain
when the screw is cracked open.
Start with air screw 1.5 turns out.
Set idle screw so that it has some sort of idle. With TORS it is the big screw under seat on top of
unit. With no TORS is is the brass screw midway down carb body.
Warm up motor and then set idle screw for a faster idle, 2000rpm+
Adjust air screw either way to get the fastest idle.
Adjust air screw a little at a time leaving 10 secs or until the motor responds.
Re adjust idle screw for desired idle .
if the air screw ends up being more than 2 1/2 turns out the pi;]lot is too big.
if the air screw is less than 1/2 a turn out the pilot is too small

 

[edgarchavez]

Is the weather temperature warming up, you may need to do a plug chop to confirm the jetting is correct.

The air screw is not a set and forget, it may need small adjustments as conditions change.

1.5 turns out is where you start to set the idle speed.

Idle speed adjusting.
Set float level, make sure that all jets are clean and fuel flows freely from the float bowl drain
when the screw is cracked open.
Start with air screw 1.5 turns out.
Set idle screw so that it has some sort of idle. With TORS it is the big screw under seat on top of
unit. With no TORS is is the brass screw midway down carb body.
Warm up motor and then set idle screw for a faster idle, 2000rpm+
Adjust air screw either way to get the fastest idle.
Adjust air screw a little at a time leaving 10 secs or until the motor responds.
Re adjust idle screw for desired idle .
if the air screw ends up being more than 2 1/2 turns out the pi;]lot is too big.
if the air screw is less than 1/2 a turn out the pilot is too small

Thank you! Let me try that out.

 

[edgarchavez]

Is the weather temperature warming up, you may need to do a plug chop to confirm the jetting is correct.

The air screw is not a set and forget, it may need small adjustments as conditions change.

1.5 turns out is where you start to set the idle speed.

Idle speed adjusting.
Set float level, make sure that all jets are clean and fuel flows freely from the float bowl drain
when the screw is cracked open.
Start with air screw 1.5 turns out.
Set idle screw so that it has some sort of idle. With TORS it is the big screw under seat on top of
unit. With no TORS is is the brass screw midway down carb body.
Warm up motor and then set idle screw for a faster idle, 2000rpm+
Adjust air screw either way to get the fastest idle.
Adjust air screw a little at a time leaving 10 secs or until the motor responds.
Re adjust idle screw for desired idle .
if the air screw ends up being more than 2 1/2 turns out the pi;]lot is too big.
if the air screw is less than 1/2 a turn out the pilot is too small

Thank you! Let me try that out.

 

[Awk08]

did you just switch to that amsoil dominator from another oil ?
my bike ran like dog poo on that dominator stuff when I mixed it @ 32:1 , it's formulated to run @ 50:1
I drained that shat and went back to Maxima Super M and never looked back


have you cleaned the carb properly.... removing the jets, poke small wire thru, carb cleaner, compressed air ?

check the float height while you're in there, and the reeds while you have carb off