G62 Problems
 

I have a G62 that I just mounted on my new Giant Stinger. I bought this engine used and it ran great on the bench but now that it's installed in the stinger it is giving me fits. Heres the specs:

Stock G62 w/pitts muffler w/ 22 x 8 zinger prop (balanced) w/ spring starter, w/velocity stack and mounted inverted. Not Cowled.

24 ounce fuel tank.
Gas: 93 octane w/ 40:1 pennz aircooled 2 stroke oil (does foaming in gas cause problems like glo fuel does?)

Problem: Starts fine, runs fine. When you go to idle it surges (leans out) then quits (starts to quit at around 1/4 throttle.) It idled fine when it had been bench run.

What I've done so far.
Remove trash from screen on the carb (opened top of carb to gain access to the screen.) I've played with the low end mixture but didn't really notice a difference in the fact that it still quits (leans out first).

What is the procedure for tuning this engine. Zenoah just says low end needs to be 1 1/8 turns out. high end needs to be 1 3/8 turns out. should I adjust high end first then low end?

What is a good target RPM at idle.
What RPM should I be seeing at full throttle?

Thanks for any help....

G62
 

A 22-8 prop is too small, you will get better results from a 22-10 Zinger or 22-12 Menz Ultra
Open both needles 2 turns from closed.
Start engine, run up to full throttle, adjust for best rpm, somewhere around 6800 to 7000(depends upon muffler),back off a few hundred rpm.close throttle to idle, around 1800 rpm..Open throttle--if it doesn't die close the low speed needle about 1/4 turn, try again..Do this until it dies when the throttle is opened, then open until you get a good transition..go back and re check the high needle..Fly......the factory needle settings are not always absolute..There are variables(high altitude, prop size, fuel, etc..Whatever works best is the correct setting.....
93 octane fuel won't run any better than 87..
Check all your fittings for air leaks, foaming should not be an issue...

G62 Problems
 

The most I can get out of it is around 6700 rpm. Thats at 1.25 turns on the H end. The lowest I could get was to erratic. 2000-3200 rpm. I couldn't keep it stable no matter How I turned the Low end without it surging and quiting.
the Bottom line is that the engine runs great. great Transission from Low to High. But something I noticed this time is that at ALL but full throttle the engine surges (leans out) when held for more than 5-10 seconds at idle thru midrange postitions. It just happens to quit at idle.

I don't have any fuel sepage the side of the carb that has only one screw holding it on. but on the bottom end of the carb I notice that there is fuel sepage. I think that this is normal, right? (screws are all tight) thank you very much for your help. I'm wondering If I need to rebuild the carb as I might be gettin air in somewhere.....

CARB
 

Fuel seepage is not normal..If the inlet needle is not leaking there is no lway fuel can leak..The needle will hole at least 10 lbs pressure before it opens..Check the lever that hooks into the needle ..It should be flush with the top of the casting..If not, gently bend it until it is..Hold the needle down while bending the lever...

G-62
 

I make sure I use large fuel tubing all the way through on mine. I also drill out the clunk.

G62 Problems
 

rcign:

I took the carb completely apart and blew out all passages. I adjusted the arm you told me too also.

So far I've got the engine to idle pretty decently. I can go as low as 1500 rpm. But a better idle is at 2000-2200 rpm.

Transission is very smooth and I can only get it to peak at around 6600 RPM.

I can't believe how much a 1/8 turn difference can make.

My only problem now is even at 1500 rpm I can't keep the Giant Stinger from moving. It just wants to keep rolling. Has anyone else had this kind of problem. And this is on rough grass. He he. Maybe I'll put a 22 x 10 prop on and see if that helps prevent the roll out....

Thanks for your help RCIGN.

and thanks for all the other suggestions. I might experiment and drill out the fuel tank clunk in another tank.

G62
 

1/16 fuel tubing any gasser up to and including a 150 3W twin is more than adequate.....