throttle is sticking some ???
10-10-2013, 08:23 PM
#3
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My pro systems carb was sticking from day one. I'd have to punch te gas hard and let it slam shut to get it to close all the way. They thought it was a mis tuned carb, turns out the return spring on the shaft of the primary's was digging into the base plate and slipping all over. I took a punch and put a hook into the end of the spring to keep it from rolling down any more. Not much trouble now. I think it's the wrong spring installed maybe... Something to look at. Took me a bit to find
10-10-2013, 08:31 PM
#4
My pro systems carb was sticking from day one. I'd have to punch te gas hard and let it slam shut to get it to close all the way. They thought it was a mis tuned carb, turns out the return spring on the shaft of the primary's was digging into the base plate and slipping all over. I took a punch and put a hook into the end of the spring to keep it from rolling down any more. Not much trouble now. I think it's the wrong spring installed maybe... Something to look at. Took me a bit to find
Another thing to watch out for from some builders is the secondary actuation link being bent too short. When that is a problem the primaries cant close because there is tension on the link.
10-10-2013, 08:55 PM
#6
I'm going to take it back down... I have another problem now cruisin alone I can smack it to the floor and it bogs all way out !!! WTH ???... STAGING IT UP IT STAGE GOOD BUT SOON AS YOU GET OFF THE BREAK IN FLOOR IT IT BOGS ???
it have 67 front jets & 73 rear jets..6.5 power valves F&B...800dp w/proform body
HELP ASAP !!!
it have 67 front jets & 73 rear jets..6.5 power valves F&B...800dp w/proform body
HELP ASAP !!!
Last edited by jaywill; 10-10-2013 at 09:00 PM.
10-10-2013, 09:06 PM
#7
My pro systems carb was sticking from day one. I'd have to punch te gas hard and let it slam shut to get it to close all the way. They thought it was a mis tuned carb, turns out the return spring on the shaft of the primary's was digging into the base plate and slipping all over. I took a punch and put a hook into the end of the spring to keep it from rolling down any more. Not much trouble now. I think it's the wrong spring installed maybe... Something to look at. Took me a bit to find
Thanks!
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10-10-2013, 09:08 PM
#8
I'm going to take it back down... I have another problem now cruisin alone I can smack it to the floor and it bogs all way out !!! WTH ???... STAGING IT UP IT STAGE GOOD BUT SOON AS YOU GET OFF THE BREAK IN FLOOR IT IT BOGS ???
it have 67 front jets & 73 rear jets..6.5 power valves F&B...800dp w/proform body
HELP ASAP !!!
it have 67 front jets & 73 rear jets..6.5 power valves F&B...800dp w/proform body
HELP ASAP !!!
Okay, lets get into it. You started out with an 800 Double Pumper yes? What model number? Should be a #4780- something. Yes?
You bought a Proform Main Body? What size and show me a link to the carb exact unit.
They gave you a recommended jetting in the kit yes?
10-10-2013, 09:13 PM
#10
There is a quick fix for this that often works. You can double rap the primary side coil spring. Just unhook it from the throttle lever and wrap it around one more time and hook it. It makes the throttle stiffer, but it is often enough to get you by.
10-10-2013, 09:14 PM
#11
We are here.
Okay, lets get into it. You started out with an 800 Double Pumper yes? What model number? Should be a #4780- something. Yes?
You bought a Proform Main Body? What size and show me a link to the carb exact unit.
They gave you a recommended jetting in the kit yes?
Okay, lets get into it. You started out with an 800 Double Pumper yes? What model number? Should be a #4780- something. Yes?
You bought a Proform Main Body? What size and show me a link to the carb exact unit.
They gave you a recommended jetting in the kit yes?
http://www.summitracing.com/parts/pro-67100c/overview/
jetting 72/84 i think
10-10-2013, 09:23 PM
#14
Okay. Here is the deal. Your primaries are too lean. I am assuming you have a power valve in the front AND rear?
If you have powervalve front and rear, then your jetting should be squared. start out with 72 front and rear or 73 front and rear if that is what you have.
I personally would plug the rear powervalve port and start out with the recommended 72/84 jetting. But, you do not have to do that.
Either way, your primaries are too lean. Way too lean.
If you have powervalve front and rear, then your jetting should be squared. start out with 72 front and rear or 73 front and rear if that is what you have.
I personally would plug the rear powervalve port and start out with the recommended 72/84 jetting. But, you do not have to do that.
Either way, your primaries are too lean. Way too lean.
10-10-2013, 09:27 PM
#15
Okay. Here is the deal. Your primaries are too lean. I am assuming you have a power valve in the front AND rear?
If you have powervalve front and rear, then your jetting should be squared. start out with 72 front and rear or 73 front and rear if that is what you have.
I personally would plug the rear powervalve port and start out with the recommended 72/84 jetting. But, you do not have to do that.
Either way, your primaries are too lean. Way too lean.
If you have powervalve front and rear, then your jetting should be squared. start out with 72 front and rear or 73 front and rear if that is what you have.
I personally would plug the rear powervalve port and start out with the recommended 72/84 jetting. But, you do not have to do that.
Either way, your primaries are too lean. Way too lean.
10-11-2013, 05:21 AM
#18
My Holley did the same thing, would stick part way open and idle at 1500 RPM unless I blipped the throttle and let it slam. I did all sorts of things. Holley had me recenter the butter fly plates. I tried multiple return springs. I disconnected the throttle cable in case it was binding. I even went so far as disassembling the base plate and cleaned up the throttle shaft bushings.
Then I bought a Quick Fuel base plate. That fixed it for a while, but it came back.
Then one day I was looking at the primary accel pump arm and noticed it was slightly bent. This made it hit the pump cam at an odd angle, maybe 30°, rather than riding right on the top. This caused it to kinda hang up on the crest of the pump cam. Straighten that out, readjusted the linkage and haven't had a problem since.
Then I bought a Quick Fuel base plate. That fixed it for a while, but it came back.
Then one day I was looking at the primary accel pump arm and noticed it was slightly bent. This made it hit the pump cam at an odd angle, maybe 30°, rather than riding right on the top. This caused it to kinda hang up on the crest of the pump cam. Straighten that out, readjusted the linkage and haven't had a problem since.