11 replies to this topic

[mini.matt.]

hello,
Just wondering r1 carbs are too much for my 998
it will have a 12g295 head on and 275 kent cam and a rc 40 exhaust system but with a bike can on the end. ( i know it ruins the performance and what not but it looks pretty nice imo)
i just wanted to know how other people have got on with them?
the fabrication side is not a problem, making a manifold for them to fit shouldnt be a problem.
just wondering as i have them sitting about in the garage !
thanks
matt

[bmcecosse]

What's the advantage ? The main power problem with the engine will be the midget valved 295 head - not the carbs! A single HIF 38 will be plenty with that head.

[Bungle]

a R1 bike engine is also 998cc

[rasputin22]

But they are designed to output over 100 bhp (i think). So the R1 carbs match to the R1 engine. They would be complete overkill on a humble 39bhp from an A series.

[Surfbluegarage]

r1 bike carbs are an awesome add on to the a series engine and do add some power... if your on a budget then stick a 38 on but if they havent cost you anything and you think you cld do it yourself then why not.. there jetted for the 998 r1 engine and run fantastically well and efficient.

[Fluffy]

I have been wondering about this myself as a regularly see some bike carbs on sites similar to Ebay.
These carbs are jetted for 998 R1 engine, but there are 4 aren't there ?
So without a 7 or 8 port head, you would be stuck with using 2. Are they still jetted correctly then ?

[jaydee]

A 998 engine with a 295 head and a kent 276 wont produce 39 bhp unless you've timed the cam totally wrong...
Let alone R1 carbs and try on the webber side.

[mini.matt.]

Okay i understand that maybe they wouldnt be as benefitial compared to ones on a highly tuned 1275/1295 ect...
but just wondering if they would be of benefit at all
like mini_mad_daps said, they havnt cost me anything
thank you for all your inputs
ill put them on and a later date prob spend a odd evening on it now and again.
when completed i will get it rolling roaded and post up the figures !
thanks,
matt

[bmcecosse]

What's so 'magic' about 'bike carbs ' ? When an SU is at full throttle - there is really only the throttle plate in the air flow - and Vizard tells how to thin it down etc. Do the 'bike carbs' have a throttle plate - or are they like the original Amal - where at full chat there is just the needle in the air stream ?

[Gr4h4m]

What's so 'magic' about 'bike carbs ' ? When an SU is at full throttle - there is really only the throttle plate in the air flow - and Vizard tells how to thin it down etc. Do the 'bike carbs' have a throttle plate - or are they like the original Amal - where at full chat there is just the needle in the air stream ?

there like a bit of a cross between and SU and Webber. they have a throttle disc, piston needle and jets to control idle, 1/4 throttle.

The piston is plastic, the throttle disc spindles are shaped for air flow... The dont use oil, only a spring and diaphragm. They have a much better choke design.

They are a modern version of an SU and loads newer...IMO a more modern design and better. They certainly work much better on my engine and that was against a fully rebuilt SU, which also had a NOS dashpot and piston.

[benmoffat]

Hi, just wondering what does it sound like with the bike can on it?

[HARBER07]

nothing.

Edited by HARBER07, 28 February 2010 - 01:58 PM.