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This post concerns a 97 WaveVenture 1100. It was very difficult to start cold and choking was ineffective. Once started (with the aid of ether) It idled rough but ran quite well and smooth at full speed. It had a very pronounced dead spot "off idle" and would often die rather than accelerate. An attempt to adjust idle mixtures revealed that all mixture screws were siezed. The carbs were removed and cleaned / inspected / rebuilt and all low speed screws replaced. The fuel tank was cleaned, new fuel filter installed, fuel pump rebuilt, all hoses replaced, and new reed set installed. Compression check showed all three cylinders at 119.
It started and ran ok on the trailer with very robust acceleration off idle. The idle was still quite rough but I hoped would correct with low speed screw adjustment. Once in the water it ran very well with great low-end power and acceleration - for about 15 minutes. After that it would die if it even approached idle but still ran ok at top speed. I parked it on the beach for a night of head scratching. The next morning it started on the first attempt, idled ok, but would not run above about half speed. Within 15 minutes it would not come off idle at all - opening the throttle to full only changed the sound of the engine without changing the rpm. Adjusting high and low speed mixture screws made no difference. That is where it stands at this point. Unfortunately my formal mechanical training all involved aircraft and, with the exception of ultralights, there aren't many 2-stroke airplanes. Compression still checks at 119 across.
Does the combination of persistant rough idle and unpredictable running behavior point to a CDI problem?
I could sure use some ideas on how to troubleshoot this . .
It started and ran ok on the trailer with very robust acceleration off idle. The idle was still quite rough but I hoped would correct with low speed screw adjustment. Once in the water it ran very well with great low-end power and acceleration - for about 15 minutes. After that it would die if it even approached idle but still ran ok at top speed. I parked it on the beach for a night of head scratching. The next morning it started on the first attempt, idled ok, but would not run above about half speed. Within 15 minutes it would not come off idle at all - opening the throttle to full only changed the sound of the engine without changing the rpm. Adjusting high and low speed mixture screws made no difference. That is where it stands at this point. Unfortunately my formal mechanical training all involved aircraft and, with the exception of ultralights, there aren't many 2-stroke airplanes. Compression still checks at 119 across.
Does the combination of persistant rough idle and unpredictable running behavior point to a CDI problem?
I could sure use some ideas on how to troubleshoot this . .