Page 1 of 2

W/ng carb

Posted: Tue Apr 10, 2018 12:48 pm
by RTichard Woolnough
hi there, I have a 276/014R carb fitted to the 1942 W/ng, needle no 6 [perhaps 9]slide no 3, she runs very rich and fouls plugs eventually, can anyone tell me what the needle, jetting and slide should be pse? kind regards

Re: W/ng carb

Posted: Tue Apr 10, 2018 1:11 pm
by dave.owen
It should have a 275, 7/8# carb, but should run OK with the bigger carb.
From memory, 106 meddle on middle notch, cutaway of 3 on slide and 150 or 160 main jet.

Dave

Re: W/ng carb

Posted: Tue Apr 10, 2018 1:11 pm
by dave.owen
I have a spare wng 275 carb available.
Dave

Re: W/ng carb

Posted: Fri Apr 13, 2018 10:02 pm
by RTichard Woolnough
Thanks for your reply's, I will keep it on the larger carb if I can, the slide is '3' I have lowered the needle to the top notch, that sounds contradictory, I have no idea what the jet is at the moment, she starts and ran quite well the 6 miles I did yesterday, I will keep an eye on the plug for a while and carry a couple of spares, just suck it an see.
The strange thing is I cleaned the old plug and stuck it in the 1949 Velo Mac I am trying to rec ommission and would you believe this old gal fired up and ran on this plug, kind regards

Re: W/ng carb

Posted: Sat Apr 14, 2018 1:14 am
by nevhunter
They run extremely well with the correct one. The military G3L matchless uses an even smaller carb. As I get older I try to keep things simple.(r) (If I really meant that I would give up old motorcycles wouldn't I?) The original with all the parts as per the book. (The info is all there and you can buy most of the parts new, the jet block being an exception as far as I know) . A larger bore carburetter is harder to tune. Oversize carbs are more critical with jet sizes, float level etc as they don't have a lot of "suck" so velocity is reduced... Put one on if you are going for top end output but at all other places it's not going to work as well. I've been running my 1941 model W/NG ( It's MY favourite bike of the options to use,)since 1999 and it's easy starting, smooth and very good economy. All bog standard. Nev

Re: W/ng carb

Posted: Sat Apr 14, 2018 8:50 am
by RTichard Woolnough
thanks Nev, I have to say though apart from plug fouling once a year! I have had no problems with the bike thus far, I took her to the Killarny mountains last year for the Irish rally and apart from crap in the main jet she ran faultlessly, and to Latvia where again there were no problems, as I say fouled plug only one nowadays. [ is that the kiss of death!] kind regards

Re: W/ng carb

Posted: Sun Apr 15, 2018 5:43 am
by nevhunter
If it's any help, the official maintenance manual says Type 275B/1J Main jet 120 slide 5/4. for the W/NG. Needle in centre notch. The needle and moreso the jet it moves in do wear to richer. Main jets are often monstered so a new one is safest. The float needle and seat wear to richer too. The float will sit higher and this affect the tickler action .Top and bottom feeds are fitted standard to the war bike. The top feed seems rarer. Nev

Re: W/ng carb

Posted: Thu Apr 26, 2018 8:46 am
by RTichard Woolnough
guess what? happened again last night, running back from VMCC pub meet following a chum on his R100 [to light the way] going O.K started to lose power and wouldn't rev then died altogether, long story short, changed to a new plug fired up first kick and away, the removed plug wouldn't spark when tried against the cylinder head, what's going on 'ere?. ? [ the mixture did seem a bit weak] as I say will try a Champion from the Green Spark co. see what this does. Bit perplexed. kind regards

Re: W/ng carb

Posted: Thu Apr 26, 2018 8:57 pm
by paul.jameson
I had a similar problem on my Red Hunter when it was a 350 with a lot of miles on the cylinder (and a whole trail of broken pistons and worn out valve guides). The bike would die and then work perfectly well on a new plug. I suspect that modern fuels may be the root cause of the problem but for me the cure was a rebuild of the magneto by Tony Cooper. The magneto in question had done about 20 years service following a previous rebuild by Ross Davis.

Re: W/ng carb

Posted: Fri Apr 27, 2018 2:39 am
by nevhunter
Magneto's have a habit of expiring after an hour or so of running when the coils get a bit old. it's due to corrosion of the fine copper wire and breakdown of the insulation in the windings generally caused by moisture, over time. It can also be the condenser which will cause the points in the magneto to burn, or build up on one of them and a much weaker spark.
IF your motor uses even a small amount of oil (as distinct from leaking it) the anti friction additives in the oil can cause the plug to fail due shorting of the insulator by a build up of zinc or phosphorus on the surface exposed to the combustion. It's apparently quite hard to remove as it gets into the ceramic surface , distinct from Carbon/dust that sometimes gets there and can be scraped off with an old hairpin easily.. It's also worth checking the high tension pick up, and brush and spring as well as the slip ring and the continuity of the HT lead.. The rotating points assembly is held there by a taper in the earlier magnetos. (Non face cam and all made of brass). The surface can get corroded on the taper. Clean it carefully with a scouring pad, check it seats properly and tighten reasonably and ensure the taper is gripping by applying a slight turning force to it in both directions. It should not move at all if it's seated on the taper. The weak keyway is to locate it only and is easily damaged so be gentle with it. Nev