Blaster Carbs

[escore]

I am done with my stock carbs. I have replaced the needle and seats 3 times with used and new ones and no matter what I do they still drizzle. I want to just buy a new set of true bored ones and be done with the 17 year old stockers but I feel like another set of 38's might be foolish. My motor is nothing special. 35 CC head. little over 82mm, port matched for now probably light porting eventually, reeds, stuffers, reed spacers, and Factory Mod. Just wondering if I should stay with the 38's or go a little bigger since I am going to spend the money.

 

[High Speed Industries]

I know many people upgrade to dual 44's. It's an easy upgrade because the carb setup can be found stock on 760cc motors, and it's pretty much bolt on. I have a super jet with a head and a pipe, I have a set of carbs that I will be putting on in a week or two. I'm hoping for an improvement.

Oh and you might want to check your pop off spring if you needle isn't sealing. I've had past problems that was caused by the wrong pop off spring.

 

[Matt_E]

I am done with my stock carbs. I have replaced the needle and seats 3 times with used and new ones and no matter what I do they still drizzle. I want to just buy a new set of true bored ones and be done with the 17 year old stockers but I feel like another set of 38's might be foolish. My motor is nothing special. 35 CC head. little over 82mm, port matched for now probably light porting eventually, reeds, stuffers, reed spacers, and Factory Mod. Just wondering if I should stay with the 38's or go a little bigger since I am going to spend the money.

You're having trouble getting stock 38's - at 55 psi popoff - to seal?

 

[tshank123]

If you've replaced the N/S on those several times and you still have dribblers then its probably not your problem. I dont suppose you have a lot of vibration? I went through hell on my 1200 with vibration and dribblers.

To your question, yes, if it were me and I was going to spend the money on some aftermarkets I would go 44s. 38s are fine for your set up, and if you had them taper bored they would be better but if you're going to spend the money go a little bigger.

 

[escore]

I have tried different springs. Its always a lot of time in between messing with them so I never remember what I have tried. But nothing seems to seal them no matter what I do. I have some vibration for sure but it seems normal to me. I aligned the motor when I bolted it in. Anything else I should be doing to limit that issue?

 

[Byeai]

Wen u buy new carbs send those to me

Sent from my SAMSUNG-SGH-I727 using Tapatalk 2

 

[tshank123]

You can try running a heavier spring, then use a larger low speed jet to compensate. The heavier spring will help it seal better against the seat. So if you're running an 80g spring and a 2.0 N/S to get 21 psi of popoff, try using a 95g or 115g spring and go up on your low speed jets by one or 2 sizes. It will take a little experimentation to figure out, but will help your problem a lot.

 

[Matt_E]

You can try running a heavier spring, then use a larger low speed jet to compensate. The heavier spring will help it seal better against the seat. So if you're running an 80g spring and a 2.0 N/S to get 21 psi of popoff, try using a 95g or 115g spring and go up on your low speed jets by one or 2 sizes. It will take a little experimentation to figure out, but will help your problem a lot.

Stock dual 38 SBN's run 1.5 N&S with 115g springs. Stiffest combination possible unless you go to a custom 1.3 N&S

 

[tshank123]

There's no way he should have any dribble then unless that thing is ready to vibrate right off the trailer. I would check to make sure you have the right N/S and spring, check the o-ring on the N/S, make sure the needle arms are level with the body of the carbs.

 

[taylor2000]

I have printed off a 20 page owners manual read it 5 times im getting it. Suggest the same to you

 

[escore]

What owners manual? I read this about 5 times. Still nno idea how to make them seal. I just gave up and been dealing with it.

http://www.mikuni.com/pdf/sbn_manual.pdf

 

[Matt_E]

It's not hard. Inspect/replace needle and seat assemblies. Possibly check the popoff to make sure it is at about 52 psi.

Once you put it back together, check if the popoff assembly arm is level with main carb body (diaphragm side of course)

 

[JT_Freeride]

Just had this happen to a set of carbs the o-ring wasn't sealing do a pop off check and put some 656 in the seat make sure it seals.

 

[catpower]

2.0 seats are too large. use 1.5 I agree be sure carb is clean down under oring seat. curious as to what 656 is? Sounds like something that would come loose with gas and oil premix. and plug up carb. use new orings and clean with break cleaner not carb cleaner. That stuff is too hot.

 

[JT_Freeride]

656 is pretty much just a better wd-40.