A little spec help please with our mikuni super bn 38I carbs

[gravia]

Hi, I just purchased 4 Mikuni 38 I super bn rebuild kits for our 96 dual 717 engine speedster. I found a link but Im not sure of the correct spring to use for the needle and seat lever. Is the correct needle a 1.2? Should it be 115 gm spring, and should the correct pop off pressure be 36-60 lbs? Anyone know for sure or have a link to a legit chart?
And who sells pop off pressure testers 60 lb range for a good price? Or should I just build my own? Thanks for the help!

 

[gravia]

Appreciate your response!

I want to replace all 4 needle and seats because at least 1 of them is giving me some leakage, rich fuel mixture at idle. I will have them all apart so for a few more bucks its worth it for me.
I think Im going to make my own pop off tester. Its seems alot easier than finding one to buy one!
Thanks for your help!:cheers:

 

[timmyboy76]

stock...

gravia...since you purchased the rebuild kit, yeah, replace the gaskets/o-rings, along with the "needle", but for the "seats, just replace the o-ring around it, AND use the "stock" spring, thats in the carb now, dont use th ones from the kit. Theres nuth'n wrong with the stock ones...:cheers:

 

[gravia]

Thanks Timmy

Is it worth it to just replace the neddle? I have found a few places that sell the needle/seat combo's, but not just the needle. Thanks

 

[Chester]

Is it worth it to just replace the neddle? I have found a few places that sell the needle/seat combo's, but not just the needle. Thanks

You can't buy the needle separately.

Chester

 

[gravia]

Thank you to all that offered advise! I purchased 4 Mikuni kits, purchased 4 needle and seats, made my own pop off tester, set the carbs up to spec, and the speedster runs excellent!!:hurray::cheers: