My son and I built a couple of SS Animals to run. I tried a 24mm flat slide and he tried a 24mm round slide Mikuni and neither one will work. Apparently the fuel is sloshing away from the jets in the corners. They will sputter and cough in the turns, but once we're back on the straights it will straighten up and run fine.
I don't understand why the stock Animal carb works fine, but a Mikuni won't? Taking them both apart and comparing them, they aren't that much different. I noticed the pilot and main jets are about the same depth in the fuel bowl in the Animal, but the pilot jet in the Mikuni sits quite a bit higher than the main. Thinking that might be the problem, I drilled the hole the pilot jet goes in (I didn't disturb the jet threads, I stopped short of that) and press fit a short piece of tubing into the hole so the pilot jet would be picking up fuel from the bottom of the bowl like the main jet does. That didn't make any difference.
The only other difference I can see is the way they're vented. The Animal carb fuel bowl over flow and vent have very small holes - just a few thousandths of an inch. The Mikuni over flow and vent are more like 3/32" - they're clearly much bigger. I'm wondering if fuel is dumping out of these openings faster than the fuel pump can keep up, and that's what's causing the fuel starvation in the turns? I think I'm going to try restricting these vents somehow - maybe solder them shut - then drill a tiny hole through the solder the same size as the Animal carb has.
I know most people would just run the Animal carb or convert to a Tillotson, but things like this bug the heck out of me and I have to either fix it or figure out exactly what the problem is!
Any ideas?
I don't understand why the stock Animal carb works fine, but a Mikuni won't? Taking them both apart and comparing them, they aren't that much different. I noticed the pilot and main jets are about the same depth in the fuel bowl in the Animal, but the pilot jet in the Mikuni sits quite a bit higher than the main. Thinking that might be the problem, I drilled the hole the pilot jet goes in (I didn't disturb the jet threads, I stopped short of that) and press fit a short piece of tubing into the hole so the pilot jet would be picking up fuel from the bottom of the bowl like the main jet does. That didn't make any difference.
The only other difference I can see is the way they're vented. The Animal carb fuel bowl over flow and vent have very small holes - just a few thousandths of an inch. The Mikuni over flow and vent are more like 3/32" - they're clearly much bigger. I'm wondering if fuel is dumping out of these openings faster than the fuel pump can keep up, and that's what's causing the fuel starvation in the turns? I think I'm going to try restricting these vents somehow - maybe solder them shut - then drill a tiny hole through the solder the same size as the Animal carb has.
I know most people would just run the Animal carb or convert to a Tillotson, but things like this bug the heck out of me and I have to either fix it or figure out exactly what the problem is!
Any ideas?