Don - Poor Hole Shot / Miss

[03TritonBill]

Don, I have a poor hole shot / miss on my 03 Optimax Serial #ot788871. Started trip before last and progressively has gotten worse to a point where I think it should be easier to locate. Plugs have only 46hrs. Use 'the coctail' EVERY tank. DFI Merc oil. Pulled the plugs and found #4 oily. The rest looked fine. No tracking on the porcelain. Compression check ok 95-105 on all. What's next? Swap coil and wire with another cylinder to see if it moves? My buddy has a boroscope and I thought I should also check the reeds. Your help is always appreciated!

[EuropeanAM]

Spark test would be the next logical step. If you don't have a multi-cylinder spark testing board.... you can utilize a timing light. Clip it to each individual spark plug lead with the engine running at idle, and watch for a clean, steady flash on the light.

Fuel/Air pressure tests, and Fuel/Air pressure LEAKDOWN tests would be next. Dual pressure (liquid or glycerin filled gauges) and service manual recommended.

Reed inspection is also in order (bore scope is a good idea for a "general inspection"... but proper inspection requires removing the intake).

[03TritonBill]

Thanks Don. Switched coil/wire, fuel injector and plug with 3 separate cylinders to see if the problem moved. It didn't. Stayed in #4 cylinder. Pulled intake for inspection and found broken reed. Pretty big piece missing. Might have seen this one with the scope. Ordered new Boyesen's. I must drive hard. This is the 2nd reed failure since I have owned the boat. First one at approx 220hrs and this one at 420hrs. Luckily no internal damage. Had fuel line leaking inside rigging tube earlier in the year and I think this contributed to this failure. Is there any way to make the reeds last longer? I use the Merc DFI oil and 'the cocktail' in every tank and perform the yearly plugs/filters/fluids regularly. Thanks for the info as always. I found this forum just after purchasing my boat knowing zero about how these motors worked and through my own need of repairs along with reading the numerous other members needs I have a much greater knowledge and assurance in doing a lot of my own repairs and maintenance. You're a very valuable resource for us!!!

[EuropeanAM]

You've covered 75% of the causes of reed failure.... clean injectors, clean direct injectors, and AVOIDING EXCESSIVE RPM'S are the remaining potential causes (lean condition or excessive RPM's).

I've dropped you an IM also....