# 2 & 3 Cyl are not firing
I have 120 # compression straight through. no vaccum at carb # 2. removed carbs and manifold to check all gaskets. all ok. if ya cover inlet of carb #1 it kills the engine. checked to make sure there were no broken value springs on the intake values. I don't understand why I don't get some vac at Carb #2 as the chambers for both carbs are inter connected in the manifold. I think I've done everything short of pulling the head and checking for burnt intake values on 2 & 3. Am I missiing something? Thanks for your help. Peter was kind enough to give me some suggestions previously but still have the problem. could not figure out how to do a followup question-sorry
hi the only other thing i can think off. is your carbs are out of balance. dont take the head off. if you have 120 psi on all cylinders. thats not your problem. check fuel supply. the float valve is prone to sticking and slithers of rubber getting in there. take the float bowl tops off to check fuel level on bad carb.where are you based? pete
WHAT I CAN'T FIGURE OUT IS WHY THERE IS NO VACUUM WHATSOEVER ON CARB# 2.
check you dont have the gasket back to front blocking the air hole easy done.
on the 65 spitfire there is no separate hole for the vac. both carbs and the intake ports are the same. Carb 2 -the port goes directly into the head for the intake on # 4 & # 3 cyl, and carb 1 port takes care of ! & 2 cyl.s. Now 1 & 4 hit perfectly. This is the craziest thing I have ever run up against. it seems even if there was no gas in carb 2 when it is running there should be suction on the carb intake.
you need to check the float bowl is full. you can have a blockage there. all the manifolds have an air hole. i had this problem on my 73 spitfire. also check out the forums on the club im in here in the uk www.tssc.org.uk you need to be a mrmber to post. there is another club called club triumph that you can post on re the vac problem check the difference through the carb inlet you should see the air hole on the good carb.