Keihin FCR Fitment M900

Goofle · 01-06-2020, 08:09 AM

As some may remember about 18 months ago I bought some carbs from America. I've had a bit of a song and dance fitting them (not from the manner they weren't a good fit, they fitted well and reasonably easily but in the manner of I've had issues with leaks of fuel and air from the t pieces and spent a lot of time waiting for spare seals from one supplier or another). Fortunately I was in no rush and my housemate at my work digs didn't particularly mind carb bits in various states of disassembly on the table for months on end.
I've now got them fitted and managed a couple of hundred miles. I must say they do seem to make a difference. The throttle response seems crisper and there does seem to be more 'uuuumpfh' in the mid and top end (Using only the unpatented and uncalibrated 'Goofle bum dyno')! The intake noise sounds different too, more raw, which I personally don't dislike but it could get a bit tiring on a long trip I'd say (the airbox lid is drilled to match the carb set up). I'm not sure if the feeling of more umpf is just due to the noise change, I think it's quicker....
My one criticism would be the return spring for the slides is very keen - again, on a decent length trip I would say it's very heavy.
Obviously as it's rather warm at present anyhow I can't comment on starting when it's cold!
Other than the carb and airbox mods the engine is standard, a M900 from 1993, with standard gearing.
That's about it, just a quick update for anyone interested!

Goofle.

01-06-2020, 08:09 AM	#1
Goofle Registered User Join Date: Feb 2014 Location: Powys Bike: M900 Posts: 334	Keihin FCR Fitment M900 As some may remember about 18 months ago I bought some carbs from America. I've had a bit of a song and dance fitting them (not from the manner they weren't a good fit, they fitted well and reasonably easily but in the manner of I've had issues with leaks of fuel and air from the t pieces and spent a lot of time waiting for spare seals from one supplier or another). Fortunately I was in no rush and my housemate at my work digs didn't particularly mind carb bits in various states of disassembly on the table for months on end. I've now got them fitted and managed a couple of hundred miles. I must say they do seem to make a difference. The throttle response seems crisper and there does seem to be more 'uuuumpfh' in the mid and top end (Using only the unpatented and uncalibrated 'Goofle bum dyno')! The intake noise sounds different too, more raw, which I personally don't dislike but it could get a bit tiring on a long trip I'd say (the airbox lid is drilled to match the carb set up). I'm not sure if the feeling of more umpf is just due to the noise change, I think it's quicker.... My one criticism would be the return spring for the slides is very keen - again, on a decent length trip I would say it's very heavy. Obviously as it's rather warm at present anyhow I can't comment on starting when it's cold! Other than the carb and airbox mods the engine is standard, a M900 from 1993, with standard gearing. That's about it, just a quick update for anyone interested! Goofle.