Blaster running lean - Help!!

[Kwaka]

So I finally got out to the lake to test the new mods to my Blaster yesterday (mod pipe, girdled head etc). It has huge top end but bogs from idle. Thought it was too rich so adjusted it and did a plug test (repeated this a few times) to the point where I had both high & low speed out to almost two turns and the thing is still too lean.

I'm running the factory mod pipe, Riva girdled head, stock carb with 145 main and 120 pilot at altitude.

One thing I noticed that worried me when taking the plugs out is that the domes turn inside the head, is that normal and could it affect the above?

Any ideas appreciated!

 

[Mike W]

So I finally got out to the lake to test the new mods to my Blaster yesterday (mod pipe, girdled head etc). It has huge top end but bogs from idle. Thought it was too rich so adjusted it and did a plug test (repeated this a few times) to the point where I had both high & low speed out to almost two turns and the thing is still too lean.

I'm running the factory mod pipe, Riva girdled head, stock carb with 145 main and 120 pilot at altitude.

One thing I noticed that worried me when taking the plugs out is that the domes turn inside the head, is that normal and could it affect the above?

Any ideas appreciated!

Not good. Replace the O rings and torque to specs.

 

[Kwaka]

Thanks. Do you reckon that could be the cause of it running lean?

 

[Mike W]

Thanks. Do you reckon that could be the cause of it running lean?

I'm by far no expert on jetting. I wish I could help you with that but 120/145 is what my jetting was for my old B1 with a mod pipe.

 

[Mark44]

Replace o rings torque head to proper specs get a tach to properly jet carbs.

Tiny tach will not work.

Mark44

 

[Mike W]

What spring and needle/seat are you running?

 

[Kwaka]

Running stock needle and seat and 95g spring.

Excuse my ignorance here but how will a tach help me jet the carb?

Thanks!

 

[Mike W]

I would get the new O rings installed before I tried any more carb adjustments. Jetting seems pretty close.

 

[Mark44]

http://www.x-h2o.com/threads/39846

 

[Dustin Mustangs]

Alot of people recomend a lower pop-off then factory pipe says to use. I'm using a 2.3 n/s with a 95 gram spring and it's close but I am planning on trying the next lighter spring to richen it up a bit. I'm running the same jets and have pretty much the same mods (add dual cooling and only one screen in my f/a).

 

[Kwaka]

Thanks all, I'm gonna start with the o-rings and then sort the jetting out from there.

One more question - What is the ideal pop-off for this set up?

 

[WB1994]

Popoff should be around 20ish , I run a 2.0 N/S with black spring and I run 120 pilot jet and 150 main jet on my blaster with head, factory pipe , taperbore carb and carbon fiber reeds.

Mikuni says to run the smallest N/S while acheiving popoff.

Bogging at idle means wrong popoff.

 

[Kwaka]

Thanks!