1949 Model 18

Jackson66 · Post by **Jackson66** » Tue May 29, 2012 10:50 pm

I'm regularly using my AJS 18 to commute to the West End these days, but its idle is erratic, and the original 89B carb is sh**ged.

I'm not a stickler for originality, just reliability, as long as I store all the bits I replace. You try restarting a hot stalled bike in riding gear whilst wedged between 3 red buses in 35 degrees of ozone.

Does anyone have good experience of monoblocks or even concentrics on these bikes? If so what?

Dave Jackson

itma · Post by **itma** » Tue May 29, 2012 10:55 pm

a monobloc will give better results than a concentric.

personally I think the monobloc is a better carb.

other conflicting opinions will be along shortly.

Samuel · Post by **Samuel** » Wed May 30, 2012 11:08 am

Or you can still get 89B refurbished- replace jets and re-sleeve and it will be as good as new - Monoblocks are cheaper though.

Jackson66 · Post by **Jackson66** » Wed May 30, 2012 9:36 pm

OK thanks. Will I need the same spec monobloc as fitted to later machines? Jet sizes anyone?
Dave

wilko · Post by **wilko** » Thu May 31, 2012 12:53 am

Can i have your old carb? There is a pin hole for your idle circuit in the jet block which is easily blocked, Close inspection needed.

Peter Lecompte · Post by **Peter Lecompte** » Thu May 31, 2012 2:22 am

Wilko, if you get it, can i get it off you? Perfect for my '49 18 downunder, which isn't going to see a lot of commuter miles, just rides out on the country roads. Peter

rex.webb · Post by **rex.webb** » Thu May 31, 2012 9:47 am

You try restarting a hot stalled bike in riding gear whilst wedged between 3 red buses in 35 degrees of ozone.
David are you sure your blaming the CARB ?
HOT stalled ENGINE = MAGNETO ??
Ride with CARE and LIVE LONG to ENJOY your Bikes and Scooters.
Insured with Peter James

Rob Harknett · Post by **Rob Harknett** » Thu May 31, 2012 11:17 am

Are you sure the carb is correct with all the correct bits.? 1946/1953 was 89B/1AK
except 1950 which was 89M/1AK.
1954 89N/1ED ( Not that correct bits will be correct without correct fuel of the era) A few tips above, to consider see Wilco's posting & Rex's, did the bike stall in cold and wet weather, is it getting hot as its retarded