Hi to all ,

I have a set of R1 carbs onto boggs manifold lucas ign 2.1 pinto jets to 1.6 mm fr31 cam facet pump and fuel reg ,thats to outline wot set up i have save a bit of time for you guys .

I have the eng running starts first time ticks over with the odd missfire on reving the eng she picks up well but as i shut off the throtal she back fires through the carbs is this down to the ign timing
I also purchased a set of carb balancers any guys balanced these carbs .any help would be grateful

does it backfire through all 4 carbs or just one in particular, r u sure you are not getting backfiring confused with the carbs 'farting', they make a kind of pfffft noise?

my r1 carbs didn't have a vacuum take off so they couldn't be balanced from the vacuum created in the manifold, so you would have to use one of the balancers that you cover the inlet with and then get a reading, you then adjust the idle screws from undernieth so the all suck the same

[Edited on 7/5/09 by omega0684]

i think its backfire as i get get a good pop and excess fuel blown back out , and seems only out of one or two of the bodies . think you have answered the Q on the carb balancing ,

if you are getting fuel thrown back at you then the inlet valve must still be open during the compression stroke, so timing may need looking at. what about the condition of the valves? do they make a good seal with the cylinder head?

My R1 enne was a bit rough nd had a misfire in one cylinder - as said the vaccuum take off isn't on the carbs (it's on the engine). However, a friend who is both clever and experienced gave me a lesson in balancing them using a piece of tube and listening to the carbs and also gave th carbs a bloody good clean out.

Now my engin run sweet as it ever could, and I'm fairly sure it'll help me get through the emissions test now.