The International CBX Owners Association

My accelerator pump seems to have no effect when trying to cold start. 1982 Prolink with 34k miles, garaged, ridden at least 50 miles per month even in NJ winter months, 1oz. Seafoam and 1oz. MMO added to each fuel refill. It runs flawlessly with no choke after 100 yards and I am extremely sensitive to drivability (ridability) over the entire load and RPM range. Forgot to mention stock intake system, recent valve adjustment, only modification is a Pipemaster exhaust which seem to be as responsive as the OEM pipes with no jet changes. After pressurizing the back side of the vacuum fuel valve until the bowls are full I use full choke and five to 10 full throttle applications it might crank for 5 to 10 seconds before it starts. If I don't use the throttle to actuate the accelerator pump it takes just as long to light under the same conditions. I don't notice any lag or flat spot on acceleration but I don't tend to wick it on quickly or use full throttle below 2500 RPM. My normal shift points are near 5000 RPM. No other complaints except I have to crank it too long on first start when cold. It seems to me that the accelerator pump should supply enough extra fuel to start more quickly. Carbs have not been touched in 10+ years but I don't want to fool with them when they don't leak and seem to work really well. My question, is it possible to replace the accelerator pump diaphragm and clean the one way valves with the carb rack installed on a CBX with the stock intake system? Info on your experience will be greatly appreciated. My problem seems trivial in relation to others so no rush for an answer. Thanks.

Joe: It's likely the accelerator pump is inoperable or frozen. Most do after a few years. It's the most maintenance-intensive part of the carbs. Nothing can be done to it with the carbs on the bike, stock intake or pods. They have to come off. But as you said, it runs pretty well and starts OK, so I'd wait until more pressing carb problems forced the issue.

Dave

Joe, this might not apply to your situation. However, with my '82, STOCK, 5 to 10 full strokes of the throttle with full choke will flood my engine. One or two is all it takes. Could this be an issue?

Dave, I agree that I should probably just ride and enjoy it until the next time it is necessary to tilt the engine. Larry, your experience just authenticates my guess and Dave's diagnosis. Great to hear form both of you and thanks for your expertise.

Larry - you must have your accelerator pump really gulping since you rebuilt the carbs - it's almost impossible to flood these things.

Dave

Honestly, Dave, I don't know the setting. When I reassembled, I just put things back together as they were. I bench-checked before reinstalling. They all threw a stream like a sailor on shore leave after a good pub crawl. For first start in Spring, even 2 pumps will often require holding the throttle partial open to 'clear' things. For normal start, don't dare twist the throttle. I dunno!

See you at VMD. Give you a call Thursday afternoon.

Larry Zimmer wrote:
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They all threw a stream like a sailor on shore leave after a good pub crawl.

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SO GLAD I wasn't drinking anything just then or it might have shot out of my nose .