Post by rcq92130 on Aug 14, 2014 18:30:04 GMT -5
OK, have all the pollution crap off the poor little thing and the Uni filter installed. Much cleaner look. Also replaced all the vacuum and gas hoses and the fuel filter.
HOWEVER ................
(1) I'm guessing the fuel pump is not operating properly (might be related to #2 since it's vacuum driven). At full throttle all will be OK for a while, then suddenly total loss of power. Engine continues to turn, of course, as I coast, and a few seconds later suddenly power is back. Just feels like the fuel bowl is run dry; then fills again and the engine is OK. I also notice the gas filter (clear) - which is LOWER than the level of fuel in the under-floor tank when the tank is full - isn't full but only has maybe 1/4 inch gas in the bottom.
It's a stock ("Jin Do" ?? maybe) pump, maybe crap, but it was OK until the above changes.
Anyone have any experience with an electric pump? If so - what's the correct pressure? 2 to 5 psi like with larger carb. engines?
(2) Manifold vacuum seems really low (might be causing #1 above). At the manifold it's about 12 inches, which in a 'real' engine indicates a manifold leak (doubtful here) or late valve timing or something. Normal is around 20 .... my gauge is a multi-gauge setup I use to synchronize the carbs on my Goldwing, so I know it's reasonably accurate or at least ballpark. Thought maybe it was ignition timing (late) ... but both the stock CDI and the ScootDwgs performance CDI give the same result. There is very little vacuum hose left - only to the carb. and the fuel pump - and those connections look secure.
Is 12 inches 'normal' for this engine? Might the "low" (if it is low) vacuum be causing the fuel starvation problem?
Grrrrrrrrrrrrrrrrrrrrrrrrrrr ...................
HOWEVER ................
(1) I'm guessing the fuel pump is not operating properly (might be related to #2 since it's vacuum driven). At full throttle all will be OK for a while, then suddenly total loss of power. Engine continues to turn, of course, as I coast, and a few seconds later suddenly power is back. Just feels like the fuel bowl is run dry; then fills again and the engine is OK. I also notice the gas filter (clear) - which is LOWER than the level of fuel in the under-floor tank when the tank is full - isn't full but only has maybe 1/4 inch gas in the bottom.
It's a stock ("Jin Do" ?? maybe) pump, maybe crap, but it was OK until the above changes.
Anyone have any experience with an electric pump? If so - what's the correct pressure? 2 to 5 psi like with larger carb. engines?
(2) Manifold vacuum seems really low (might be causing #1 above). At the manifold it's about 12 inches, which in a 'real' engine indicates a manifold leak (doubtful here) or late valve timing or something. Normal is around 20 .... my gauge is a multi-gauge setup I use to synchronize the carbs on my Goldwing, so I know it's reasonably accurate or at least ballpark. Thought maybe it was ignition timing (late) ... but both the stock CDI and the ScootDwgs performance CDI give the same result. There is very little vacuum hose left - only to the carb. and the fuel pump - and those connections look secure.
Is 12 inches 'normal' for this engine? Might the "low" (if it is low) vacuum be causing the fuel starvation problem?
Grrrrrrrrrrrrrrrrrrrrrrrrrrr ...................
