boggong spree

[veithouse]

My spree bogs at 3/4 throttle. tried different carb(known good one) changed reeds, coil filter on filter off. could it be low compression?

[matzke3]

First I would check the fuel flow available to the carb (there has to be vacume applied to the other line of the petcock for fuel to flow). Second I would check the exhaust for plugging or decarbon it. A compression test takes a few minutes and will give a good idea of the condition of the internals so check that too.

[spree-rider]

pull sparkplug. it could possibly be lean.

[Trafficjamz]

My spree bogs at 3/4 throttle. tried different carb(known good one) changed reeds, coil filter on filter off. could it be low compression?

Make sure the air box is sealed up tight.

[veithouse]

it was the carbon build up in the exhaust port.

[mousewheels]

Hey good work
While it's close in your memory, could you help out by drawing the approx port shape and obstruction you cleared out? I think it would be good info to all.

[veithouse]

I can describe it, the port is oval around an inch wide, 3/8 inch high, the hole was reduced to the size of a pencil. had to take off the jug and clean it out. put it back together and it runs good around 30 mph.

[mousewheels]

Thanks - I've had some to take pics of, but never that obstructed.

Good info for all

[killerpancake]

is there any cleaner to run through the engine to get rid of carbon build up? will sea foam do that?

[spree-rider]

yes ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

[killerpancake]

thanks

[Bear45-70]

Cheap oil it the villain in this situation. Run good oil and this won't happen.

The marine 2 stroke industry for years has had a product that is called "Engine Tuner". Warm engine up, spray the stuff in running the engine above idle (major smoking will ensue) and then slowly back off on the throttle until engine dies. Let engine set for 20 minutes to and hour and then fire it up and run it at WOT. It removes carbon and other nasties from your engine.

I bought an antique engine for my collection once for $20 that would barely run due to the crap oil the owner used in it. After a cursory inspection thru the intake ports, it had stuck rings, compression was low and it was full of cardon. So as a test I used engine tuner on it once a week for 6 weeks. At the end, compression was back up to the minimum specified and the thing ran rather well. When I tore it down for the restore that winter there was only one ring partial stuck (I was able to free it up and reuse it) and almost all the other carbon and crap was gone. The stuff works.