Jetting Keihin FCRs

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Latest settings:

Needles in position #2 (were #5)
Slow fuel screws 1/2 turn out
Slow air screws 2 turns out
Replaced #152 main jets with #145s.

Getting there....
 
Finishing motorcycles at this time of year

Jeandr said:
.....not to mention the job jar (fun stuff like painting windows, pulling weeds...) which for some strange reason keeps filling up.
Jean

I would recommend a high strength two part epoxy applied to the threads of a solid jar cap.
:wink:

Its looking good Jean.
Are those Sun rims? Nice Suzuki front hub/brake - powdercoated? What is your 40 spoke rear hub from?
 
Re: Finishing motorcycles at this time of year

teeb said:
Jeandr said:
.....not to mention the job jar (fun stuff like painting windows, pulling weeds...) which for some strange reason keeps filling up.
Jean

I would recommend a high strength two part epoxy applied to the threads of a solid jar cap.
:wink:

Its looking good Jean.
Are those Sun rims? Nice Suzuki front hub/brake - powdercoated? What is your 40 spoke rear hub from?

Sorry for the late reply, I was out cycling, did Montreal to Boston to New York with some friends and my daughter. this was her first long trip, first century (100 miles). Over 6500 meters of climbing and close to 1000Km in 7 days, very proud of her.

Now for the answers, yes, these are indeed Sun rims, from Bucchanan's in California. The Suzuki hub was just painted with a HT black rattle can. I heated the parts to be painted in the oven to 200° F and sprayed it while it was warm, then I put it back in the oven for about an hour.

The rear hub is from an old Ducati 860, I think it's from the late seventies or early eighties.

Jean
 
You guys tell me when you want me to shut up already, but for anyone interested:

Latest settings:

Needles in position #2 (were #5 originally). I think they could go to #1 position profitably, but I haven't done it - yet.

Slow fuel screws 2/3 turn out. I was getting some popping on the overrun at 1/2 turn, which 2/3 has mostly eliminated. I think a little
popping on especially "violent" overrun is a good thing. Could be wrong...

Slow air screws 2 turns out

Replaced main jets (originally #152s) with #140s, down from the #145s I had done last time around. Still seems not too lean at WOT, so all the better. May try 135s, but I think I'm close.

More than you may want to know, I realize, but in case it helps - particularly folks who have gotten FCRs supposedly "pre-jetted," and wonder why they're fouling plugs and/or getting 35 MPG....!
 
At least one here following the updates with interest, keep up the good work.
 
Newest settings seem good so far NTST8. (140 mains; needle clip in #2 slot; stock pilot jets; slow air screw out two turns; slow fuel screw out 5/6 turn).

I will check the plugs in a bit. Would be interested in what mileage I'm now getting, but my speedo/odo is summering on Long Island (off at Nisonger's being rebuilt)....
For 35mm carbs I would think going smaller than 140 main probably not appropriate, but I may raise the needle clip to position #1 at some point and see what happens.

What settings are you running?
 
Brian

I have suffered from a severe bout of inactivity, on the Norton front at least, of late so still running the out of the box settings. Although between work and wet winter weather i have hardly ridden in the last 6 - 8 weeks so more like sitting than running.
I have a charging or charge light issue to sort out, and then some mufflers which seem to choke the engine above 4500 rpm to sort and then it is the carbs turn.
Being a bit of a lazy so and so i have contacted a local dyno shop to get an idea of costs to dial them in, and it did not sound too bad.
Will update when i make some progress.
 
Keep at it Brian!!!

Keep at it Brian!!!

When I do eventually get my set I will borrow your settings.

all the best Chris
 
Just to report back that the latest settings (see above) are IT. Bike runs like the proverbial scalded [choose your animal] and the last tankful yielded 56 MPG!!! (Those who've followed this winding saga will recall I was getting 35MPG with the "as-delivered" settings.)

LOVE these carbs! Took a bit of work (don't even ask me about installation - what a bear! - and they killed my fancy right side aftermarket petcock - bored a hole in it!) to dial in, but mighty sweet now.
 
Just to report back that the latest settings (see above) are IT. Bike runs like the proverbial scalded [choose your animal] and the last tankful yielded 56 MPG!!! (Those who've followed this winding saga will recall I was getting 35MPG with the "as-delivered" settings.)

LOVE these carbs! Took a bit of work (don't even ask me about installation - what a bear! - and they killed my fancy right side aftermarket petcock - bored a hole in it!) to dial in, but mighty sweet now.
 
Good to know, as I'll be running FCR 35s on the 880 project. I might need a tad more fuel for the additional cubes, and bigger valves though. It should be fun.
 
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