Hey guys!

'Yamaha660R' said a lot of Yamaha riders were using dual Keinins, but I didn't find anything on searching Yamaha site.

I was planning to get Keinin 39mm's, and your atv's are pretty close to same as my bike.
Since I can't find any BMW F650 owners who use Keinin's, could I ask a couple of questions if there is anyone using them here please?

I am removing 'cat', boring out mufflers, and 'could' add air ducts in air filter box for street bike (but that will reduce air pressure, so...). The 'magic' to this change was the 39mm fsc carbs.
But now, I hear from 'dyno butts' that its too much of a carb volume change there will be NO LOW/MID throttle range: just red line power.
My only feedback to them is that is the only alternative carb supported for my engine and Keinin's were supposed to atomize very nicely (almost like fuel injection).

Riding on dune's may not be as urgent as getting out of the way of a mini-van driver talkin on a cell phone, but you are the expert Keinin world user population. Could I get some feedback on TORQUE, and possibly see any dyno charts if anyone has done this and has a convenient way to send a file (97 Word?)?

I have found out lengthening the Snorkel will increase pressure and may make a (5%) difference if I could only see a dyno torque curve.


Thanks!!

 

Not real sure what you just said there...

But I have 39mm FCRs and they work great. FCRs have accel pumps that helps with throttle response. Course my Raptor is heavily modified and 720cc's...

From what I tell from your post, If you are riding a stock bike you don't need FCRs. Do some engine mods first.

 

Kenz,

Thanks. That may be the best advice. I was trying to just increase fuel/exhaust flow for performance, but my only fuel alteration option was a jump to Godzilla. I don't need a throttle hesitation on the street. So the 'mild' carb/exhaust increases will just give you throttle hesitation: sounds realistic.

I appreciate your expertise.

 

No problem, we are all learning here in the quest for more power. There is lots of information to be gained on these forums. You can use the search feature and read up on past discussions about mods such as pipes, cams, carbs, porting your head (best investment) and set-up. But of course if you can't find it there always post your questions, somebody will have done it and either screwed it up or got it right.

By the way Kenz refers to the man who ported my motor and helped me...go here for more info: Kenz Cycle Tech