Running 1600 TP on a late bay, 009 Dizzy, Empi 34 Carb with pancake filter Engine rebuilt October 2012 using new parts. Engine starts, idles and runs perfectly until 20 mile into journey. Slight stuttering leading to occasional backfire then lose of power on acceleration. Back firing becomes more common until van limps back home feathering accelerate to drive accordingly. This happens on a daily basis. 20 miles in and..... Work done to date, replaced fuel tank and fuel filter, Carb cleaned 3 times air and fuel mixture tuned, Dizzy 009 regulated. Engine to date from build 600 miles, oil changed 400 miles in. All manifold are hot, carb does'nt ice but is cold. Last week we had water in the carb, cleaned out and re-installed but still the same problems. Cannot work out why this problem exists, possibly a bad carb could replace with an original and apply original oil cooler? Change dizzy to vacuum? Any thoughts? Regards
Thoughts: crappy EMPI carb (I'd stick with an old Solex meself), can't think where water would come from. Manifold icing will give you a horrible flat spot (I'd get rid of the bling air filter). Could be coil misbehaving when it's hot (hard to diagnose without swapping for a good un). Condenser breaking down. Won't be the cause of your prob, but I'd get rid of the 009. It brings no advantages.
Thinking the carb I have this setup on another bus and its a dream to drive, never a problem. Dizzy 009 I've read a lot about this over the last few weeks, could change to vacuum but I don't see this as the issue, a dream to drive for 20 miles and then...
as said sounds like something getting hot and breaking down, could be condenser or coil. also air leak on carb or manifold making mixture weak. this wont show until the choke is right off. how have you timed the 009 ? from static or max advance.
Change seals on Carb no leak there, 009 timed from advance. Looking at changing 009 elec to manual. Timed from static maybe look to invest in the strobe light!
Coil or condensor breaking down when hot or exhaust leak when parts are hot Also check the o rings on the adjustment screws on the carb
with the 009 the advance at 3,000 revs is more important than what tickover it should be 30 to 32 cant remember the measurement from tdc but someone on there will know. they seem to have varying rates of advance but as long as you get the top setting right the lower end should take care of itself.
Okay I've changed the 12V coil today, moved away from Pertronix Flame thrower II to a Bosch unit. Drove 50km and an absolute delight, powering uphills never missed a beat. I'll up tomorrow to 100km and fingers crossed Thanks for the help
