Afternoon all,
I'd be grateful for any advice Forum Members can offer with a strange carb problem that I have just picked up.
The bike is a C Rapide, 12 volt Pazon Ignition and recently snapped a front carb throttle cable at the throttle end.
The bike was running fine before, it has air filters push fit onto the carb bodies.
The bike has unusual 276's on it, bolt on flange from a bike other than a Vincent but they have been nicely done and nicely set up - I have done 2800 miles on it with just John Coates doing a carb tune for me and it running like a different bike after that.
When the cable snapped I ran it home about 10 miles at 30/40 miles per hour with the front cylinder running on tickover once the cable snapped.
So, what I've done:
1 - Tank off
2 - Carb top off, slide and needle out to disconnect old cable
3 - Make up new cable and fit, replace slide/needle unit
4 - Carb top back on as before
5 - Replaced rear carb throttle cable at same time
6 - Refitted tank
7 - Sync'd the throttle opening on the cable adjusters
8 - Changed the oiled front plug - running NGK 7's
9 - Went for a run and found the jet body nut loose and petrol around the base of the carb body (I hadn't touched it that I know of - maybe nudged the float chamber and that has done the deed?)- tightened.
10 - Went out today - 10 miles into a run the front plug fouled and bike went onto one cylinder - running very rich when I took plug out.
11 - Hadn't touched the settings on the slide or air on the carb that I know of.
12 -Tried opening the air screw - didn't seem to make much difference as it was the one and a half out at least. Started the bike - ran on one cylinder again.
13 - Whilst riding along, took off the air filter on the way home - seemed to make a huge difference (weakened mixture I guess by allowing more air to flow and bike ran smoother as a twin all the way home.
14 - Whilst riding and pulling plug lead off the rear cylinder, when I open the throttle the bike bogs down, I can look down and see petrol spitting out the front carb bellmouth.
15 - When I do it the other way around, the rear carb pulls cleanly.
16 - Plug still black and sooty when I got home (30 miles).
What is puzzling me is that everything was working fine before and now I have it running very rich to the point it fouls the plug and goes onto one cylinder.
The only other work I have been doing is replace the dynamo which unfortunately fried itself because I had not checked what bulb was in the headlight when I bought the bike and it transpires that it has a big 55/60watt halogen thing - mmmm - one nicely cooked dynamo which threw commutator segments.
On the carbs and rich running - has anyone come across something similar before and can point me in the direction of anything to look at?
Much appreciated all.
Regards
Stuart
I'd be grateful for any advice Forum Members can offer with a strange carb problem that I have just picked up.
The bike is a C Rapide, 12 volt Pazon Ignition and recently snapped a front carb throttle cable at the throttle end.
The bike was running fine before, it has air filters push fit onto the carb bodies.
The bike has unusual 276's on it, bolt on flange from a bike other than a Vincent but they have been nicely done and nicely set up - I have done 2800 miles on it with just John Coates doing a carb tune for me and it running like a different bike after that.
When the cable snapped I ran it home about 10 miles at 30/40 miles per hour with the front cylinder running on tickover once the cable snapped.
So, what I've done:
1 - Tank off
2 - Carb top off, slide and needle out to disconnect old cable
3 - Make up new cable and fit, replace slide/needle unit
4 - Carb top back on as before
5 - Replaced rear carb throttle cable at same time
6 - Refitted tank
7 - Sync'd the throttle opening on the cable adjusters
8 - Changed the oiled front plug - running NGK 7's
9 - Went for a run and found the jet body nut loose and petrol around the base of the carb body (I hadn't touched it that I know of - maybe nudged the float chamber and that has done the deed?)- tightened.
10 - Went out today - 10 miles into a run the front plug fouled and bike went onto one cylinder - running very rich when I took plug out.
11 - Hadn't touched the settings on the slide or air on the carb that I know of.
12 -Tried opening the air screw - didn't seem to make much difference as it was the one and a half out at least. Started the bike - ran on one cylinder again.
13 - Whilst riding along, took off the air filter on the way home - seemed to make a huge difference (weakened mixture I guess by allowing more air to flow and bike ran smoother as a twin all the way home.
14 - Whilst riding and pulling plug lead off the rear cylinder, when I open the throttle the bike bogs down, I can look down and see petrol spitting out the front carb bellmouth.
15 - When I do it the other way around, the rear carb pulls cleanly.
16 - Plug still black and sooty when I got home (30 miles).
What is puzzling me is that everything was working fine before and now I have it running very rich to the point it fouls the plug and goes onto one cylinder.
The only other work I have been doing is replace the dynamo which unfortunately fried itself because I had not checked what bulb was in the headlight when I bought the bike and it transpires that it has a big 55/60watt halogen thing - mmmm - one nicely cooked dynamo which threw commutator segments.
On the carbs and rich running - has anyone come across something similar before and can point me in the direction of anything to look at?
Much appreciated all.
Regards
Stuart
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