jbflier

This is my 2nd G-62, 4th Zenoah, and first time I've encountered this problem. Here's my set up on an 18lb Edge 540. New G-62, J&A Peacekeeper muffler, APC 22-10 prop, fuel/oil mix at factory sug. 40:1. The cowl is currently off for first flight/engine adjustments. The engine starts, runs ok, idles, etc on the ground. When I start my take off run, all is fine until 1/2 throttle, when the engine bogs down like it has gone lean. But, no matter which way I go with the needle adjustments, (and I've tried lean/rich in all directions on both needles) it doesn't seem to change/correct my problem. Twice the plane hit a bump in the runway and was airborne. The plane flies great, the engine seems to perform better once it's up in the air,(even at full throttle straight & level) but if I start to horse around a bit, it starts to lose power again. When landing, the engine idles fine all the way back to the pits. I've checked the fuel tank on the ground and see no signs of air,etc. Any thoughts, help, suggestions are greatly appreciated in advance....................

jbflier

Nothing from anyone?............[sm=confused.gif]

geardaddy

My Feedback: (27)

Perhaps swap a carb from another engine.

transmission_dr

My Feedback: (1)

Hi,

Some people have had problems with the air vent on the carb pump cover. If it is in disturbed air it will affect the mixture in flight, the cure is to solder a brass tube over the breather hole and run a vent tube back inside the fuselage to breath undisturbed air.

Some engines are also sensitive to the air blast over the carburetor, adding a velocity stack may help.

HTH

Antique

My Feedback: (4)

If you have the new brown block under the carb you could try putting the old stock one back on and using the link and bell crank for the throttle...The blocks have been a source of problems....

jbflier

Thanks for the replies. The cowl is off of the plane, so I wouldn't suspect the airflow to be a problem, but.... The engine does have the brown block, so I'll keep that in mind. A good friend races the Giant Scale AT-6 circuit, and he suggested trying Lawn Boy Ashless oil for the first few gallons. (Actually he claims it's all he ever uses.) I'll try that tomorrow and see. For years I've used Bel-Ray MC-1 without problems, but maybe....I'll get it eventually, and again I do appreciate the advice..................

Antique

My Feedback: (4)

The oil is not the problem...And if he was successful in racing, I have looked inside his G62..We inspect the top 5 finishers after the finals....

jbflier

Scott Hanbury; Mentor. OH?...........

AJF--2

My Feedback: (119)

Our club has 2 of the newer G62s with the new direct linkages that has the carb turned different and both had the same problem and both were fixed with soldering the brass tube and running the tube behind the engine. Ralph is correct in that the newer block turns the carb to a position which airflow is blowing directly into the small hole. If you don't want to solder the tube you can use the old block and change the linkage and this will fix the problem. BTW-- having the cowl on or off will not have any effect either way if this is the problem.

AJF--2

My Feedback: (119)

Almost forgot-- another way to fix the problem (if you don't like to solder) is to take a piece of small thin KS Sheet metal and mount it to the carb and bend it over to protect the hole-- sorta like making a shield.

Antique

My Feedback: (4)

JB..Scott is the president of our race association, USRA..One of the best pilots around....I always have to look at his G62, he's a WINNER....

jbflier

RCIGN1; You'll laugh at me when I tell you that I discovered my problem. I even thought of this earlier, and said to myself, "no way". But..... I took the carb off at the field and don't ya know that when I locktited the insulator bolts in, I put the block in upside down and "voila" my problem is now solved, and my G-62 and myself are very happy campers. If you're in Kansas, you'll see Scott and his T-6. I'll let him tell you why it's the only plane he'll have there. Thanks again for the help/suggestions............