I have a Nelson .15 rear exhaust which is basically a three and half inch tube straight thru. The engine is designed to run full bore all the time as it has no throttle. I wish to sport fly it in a quarter midget and be able to have throttle control. Nelson says thats not possible but I know that there are people out there that can tell me how to do it. If you are one of those people I would greatly appreciate your input. Many thanks

That's one **** of a good engine you have there . One of the guys in our club had one in a CL combat plane and, as an understatement, it was most impressive. I see no real reason why it couldn't be made to run quite well with a carb although I wouldn't expect a very low idle but with the fine pitch prop usually used on them I doubt that'd matter too much.

Back in the early days of Quarter Midget, the engines had throttles. The K&B .15 used a Perry, and I think the Rossi's were also fitted with the same though that was done by the importers or distributers. Those engines had milder timing, because at that time the rules required the engine to idle. The later engines did not have that requirement, and the Cox (modified by Young???) and at the end, the Nelson dominated the event. Neither will idle very well with a throttle.

QM models flew pretty well, and were only slightly faster than a Rossi powered quickie. Put a 6x5 or 5 1/2x5 1/2 prop on it and let her rip.

I'll add... They had throttles because the rules, in the beginning, required them. If I remember correctly, the rules said the engine had to idle slow enough so the airplane didn't move on its own while idling.

Bill Vail
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