I am thinking about instaling a kehin carb on my montesa 315. could anyone out there who has done this before tell me what jetting should be?

maybe try to get the specs off another trials bike that comes with one stock , and then go to http://www.carbparts.com/keihin/needles_tu...g_your_carb.htm and fine tune it ?!

And a flatslide made a world of difference on my old 240 pro , so I'd bet you'd love it on the montesa !

good luck ,

Glenn

I am thinking about instaling a kehin carb on my montesa 315. could anyone out there who has done this before tell me what jetting should be?

Here's the jetting for a Keihin on a 300 Pro, and I'm guessing you should probably start with a 118/120 main on the 250:

MAIN: 122

PILOT: 45 (48 OK)

NEEDLE: JJH (CENTER OF FIVE POSITIONS)

SLIDE: 3.5

AIRSCREW: 2.5 TURNS OUT

FLOAT HEIGHT: ARMS IN LEVEL PLANE WITH FLOAT BOWL BASE (PARALLEL)

Jon

I had one fitted, this is what I have in my black book!

Pilot 42,

main 118,

needle GFH,

slide 3.5

Thanks for the info.

I am thinking about instaling a kehin carb on my montesa 315. could anyone out there who has done this before tell me what jetting should be?

...Give the OKO a go! They are a quarter the price of a Keihin PHK and all the jets interchange...plus the choke can be put on easily...search for OKO 28mm on e-bay...mine works a treat

I've just fitted a Keihin PWK to my 2000 315R. Here's the jetting specs in case it's useful to anyone:

#48 slow

#118 main

GFH needle clip 1

3.5 slide

mixture screw 1 1/2 turns out

I should add that this bike has some sort of carbon fibre type reeds that I assume are non standard (I wouldn't be surprised the head had been skimmed and / or some porting done, the motor had that 'look' about it - unusually clean and free of casting marks etc when I did the mains a while back)

It does feel as though it would be ok with a #116 main or different needle to lean out the mid to top range a little more, but is fine as it is for my novice abilities.

The throttle response is much better than the previous dellorto PHBH. I was struggling with double blips but could do it straight away with the new carb.

I purchased the carb as a kit with airbox side reducer, small angled carb top and throttle cable from Allens Peformance It was over £200, but a worthwhile modification in my opinion. The downsides are that it is impossible to get at the tickover screw (could be fixed with one of those bendy adjuster things) and the float bowl overflow barely clears the cases, crushing the pipe.