38/38 trouble

[Guest Anonymous]

I put a used 38/38 dgas on my 76 and absolutely loved it for about 2wks. Then it started running like crap taking off from an idle up to about 3,000rpms. It runs just fine at idle and when you're on the gas above 3,000 rpm's. I did some ignition troubleshooting and pulled the carb apart and sprayed through all the jets and changed the accelerator pump diaphragm while I was at it, but alas no dice. Out of desperation I slapped the old 32/36 back on and it runs fine. I really liked the 38/38 when it was running right so I guess I'll start w/ a rebuild kit, but is there anything in particular I should pay attention to? The problem I was experiencing wasn't a flat spot but more of a sputtering/running like crap. I've checked the archives but any additional insight would be appreciated.

Thanks! Chris

[Mike Self]

Since it was running OK for a couple of weeks, it doesn't sound like anything that was basically wrong with the jetting, venturis etc, so look at these two items:

Clean both idle jets out thoroughly, and squirt the passages with carb cleaner. The changeover from the "idle" circuit to the main jet circuit occurs at around 2500 rpm, higher than most folks realize.

Next, make sure the accelerator pump is functioning. With the engine off, look down the carb throat and work the accelerator linkage quickly. You should see a squirt of gas emerging from a nozzle in the primary barrel. No squirt, no pump action. That means either a plugged nozzle or a bad accelerator pump diaphragm. Both are easy fixes, and the diaphragm is available as a separate part from the rebuild kit.

Happy troubleshooting

mike

[Mike87]

I would look at your accelerator pump circuit first.

[c.d.iesel]

.................... float level ?

[mossyboy6]

timing?