1950 VB trouble starting

[simon.holyfield]

ok thanks. Where might I be able to buy a suitable spacer ? Not sure there'd be anywhere here in N.Z.

Easiest way is to buy some phenolic sheet on eBay and make one. It's dead easy to cut - hacksaw and files.

[bevanclark]

Thanks Simon, will look into that. Would need to extract the rusted in studs and replace with longer ones I guess if I fit a spacer. Not a lot of clearance - about a fingers width from the carb mouth to the oil tank.

I have reassembled the cleaned carb after lapping the flange flat this evening. Did not touch the mag. Bike started first kick and idled ok once warmed up a bit. Will take it for a longish run next week and see if restarts OK.

[simon.holyfield]

Thanks Simon, will look into that. Would need to extract the rusted in studs and replace with longer ones I guess if I fit a spacer. Not a lot of clearance - about a fingers width from the carb mouth to the oil tank.

To start with you could use half-nuts - that would let you test the spacer as a solution to the starting problem; then if there is an improvement, fit longer studs.

A spacer made a huge to the float bowl temperature on my Mk1, but that doesn't use a 76. To be honest I'd be surprised if that's your problem but then again I have no experience with side valves - yet!

[nevhunter]

Make sure the EX valve clearance is still there when hot. Check the Maggy when hot. Everything gets hot behind that cylinder. Check the fuel cap breather hole. Disconnect fuel line and blow through it. Check mag points freedom and gap. Try a different Plug. Some oil additives can short out the insulator. Make sure you don't have suppression leads or Resistor plug. Nev

[charvey]

Hi all,
I had a problem with clearance on my 29 between the carb and the oil tank so I replaced one of the studs with a bolt and with that removed I can swivel the carb to give a bit more clearance to get it off if that helps, Clive.

[bevanclark]

Thanks Clive,
I can get the carb off ok; it is more that I would have liked to attach an air filter but it is simply impossible unless I swapped the oil tank for slimmer type.

[Gui.dorey]

Hi Bevan,

Also check if your exhaust lifter is not stuck or touching the ex valve when hot. Sometimes it’s a simple thing like that. And as said before, recheck valve clearances.

The spacer is always a good idea, but I would doubt that’s the problem and would suspect the ignition. Check points gap, spark plug gap or try a new plug, and check if the timing is still correct, make sure the slip ring on the mag pick up is clean and the pickup brush is fine and contacting the ring.

Best of luck,
Gui

[garycullen]

Hi Bevan,
Here is what I did ti fit an air cleaner to my VB, same s yours not much room between the oil tank and the short velocity stack on the carb inlet.

I visited the $2 shop and bought a small kitchen sieve with fine SS mesh.
Cut it out and formed it around the velocity stack and spot glued with JB Weld around the perimeter. ( The JB Weld that takes 24 hours to cure, not the quick set stuff )
Then found some fine black foam ( actually a pull out piece from a customised tool draw inlay.) and squashed it over the throat and pushed it in-between the oil tank. Works okay and it didn't blow off when I tried to start with the lever at full advance . Big Back fire ! no burns on the foam either.
Sorry if the pictures are not around the right way. Click on them and they are okay.

[garycullen]

You could also spray the foam with air cleaner filter oil...

[JohnnyBeckett]

hi, you can get a insulated spacer on Ebay in diffent thickness i have just fitted a 1/2" thick insulated spacer to a NH that i am rebuilding and i got it off Ebay