Just wondering if anyone has fitted a Yost power tube on a HSR 42 or 45 Mikuni carb? Any noticeable diference or a waste of time? The local Harley mechanic told me it won't make any difference on this carby. Your thoughts please?

http://yostperformance.com/products/...les_mikuni.php

 

I can't comment on the Mikuni HSR, but I had great results with a Yost kit in an S&S Super E. It really smoothed the midrange and provided crisp throttle response.

 

I did a bunch of interweb research on those and the consensus was a waste of time in Mikuni's.

 

The Yost Power Tube adds an extra circuit to carbs like the S&S, even two of them in some cases, however the Mikuni has several circuits built in, hence jetmech's reply.

 

Ok cool. Thanks for the replies. Looks like my local Harley mechanic was correct. He said if it was a S&S carb i would notice the difference, but not on a Mikuni.

I always like to double check though, hence my question on this forum

Cheers!

 

now I'm interested - will I notice a difference with my S&S G carb?

 

My Harley mechanic said if i had a S&S carb he'd recommend fitting one. I had a 98 Evo Fatboy that was running the standard carby & when i fitted the Yost power tube it made alot of difference. A few more ponies i could feel & crisper throttle response. I'd go for it if i ran an S&S or standard carby. Cheap too.

 

Lyn, I have a G on my S&S 107 and to be frank I suspect you won't benefit! My indy, who installed my engine, also around the same time installed an S&S 124 in a Dyna. He has subsequently worked with the owner to develop that bike into a street/drag bike. In race tune it has a D carb with two Yost tubes, but was giving well in excess of 160HP (owner and indy won't admit to exactly how much!). The Yost tubes add extra circuits to fill flat spots in the fuelling, for flat out performance, not something I believe we fellow 585 cam owners suffer from or really need! A chap can only use so much OMG on the street......

 

i put one in my mikuni in 2000 (98Dyna) and it was smoother, seemed to start better. not a huge difference but, i ran it for a few years (sold bike). it went lean on WFO so i could've used a bigger main jet. try and see for yourself, they aren't hard to put in or expensive. It will be a much more noticeable difference in a less complicated carb like stock keihin or S&S. Around same time my friend put one in a super E (S&S)- different bike afterward.