GP 61 -Discussion thread

[Lorne@pro-rc.ca]

Jetpainter;4251 wrote: Nebwake, I just checked the needles on my GP61. The low is at 2 1/4 and the high is 1 1/4. That's a long way off from stock, but it runs good there.

That sounds a little lean on the top.

I have tuned a bunch of customer engines and most are lean on the top. (When warm the rpm will drop further and motor will run hotter)

Make sure it is a little fat on the top by getting it 200 rpm rich and then lean back 150 rpm. Remember to compare a warm engine to a warm engine.

The only problem with the GP61 and 123 is they get hotter when lean but don't fall off rpm too much

 

[Lorne@pro-rc.ca]

Bdegan;4819 wrote: amen !!!!!!!!!

Yeah, I agree, no two engines tune the same way. They are always plus or minus at least a 1/4 turn

 

[Jetpainter]

Lorne @pro-rc.ca;5278 wrote: That sounds a little lean on the top.

I have tuned a bunch of customer engines and most are lean on the top. (When warm the rpm will drop further and motor will run hotter)

Make sure it is a little fat on the top by getting it 200 rpm rich and then lean back 150 rpm. Remember to compare a warm engine to a warm engine.

The only problem with the GP61 and 123 is they get hotter when lean but don't fall off rpm too much

It 1 1/4 may sound lean, but I can assure you in reality on my engine it certainly is not. It still sounds rich in the air and the plug verifies that. When I stated that "it runs good there" I meant reliable idle, good transition and good performance. After it gets some more fuel through it I will lean it out some until it sounds clean and the plug looks good.

 

[Lorne@pro-rc.ca]

Jetpainter;5421 wrote: It 1 1/4 may sound lean, but I can assure you in reality on my engine it certainly is not. It still sounds rich in the air and the plug verifies that. When I stated that "it runs good there" I meant reliable idle, good transition and good performance. After it gets some more fuel through it I will lean it out some until it sounds clean and the plug looks good.

cool. Unless you fly around at 1/2 to full throttle the plug is an indication of the low needle, if black rich on a the low needle.

Like brad said, every engine runs different. When engines get to my shop with about these needle settings I find the bottom is often rich and top end is lean so I thought I would say something.

Enjoy your flying.

 

[Jetpainter]

Lorne @pro-rc.ca;5424 wrote: cool. Unless you fly around at 1/2 to full throttle the plug is an indication of the low needle, if black rich on a the low needle.

Like brad said, every engine runs different. When engines get to my shop with about these needle settings I find the bottom is often rich and top end is lean so I thought I would say something.

Enjoy your flying.

Lorne, thanks for the interest, and normally I would agree with you on high needle being that far in, but that is what it seemed to need.



When it was new it wouldn't even start at the factory 1.5 out needle settings. It would pop on the choke, but that was all. I slowly richend the low side it until it would idle then more until it would take some throttle then more so it would advance all the way to wide open, where the high side was blubbering rich. I then leaned the high some until it didn't blubber too badly. When I check the transition it still had that hollow sound right off idle that they get when the low side is lean so I richend it until the transition was good. Since then I've leaned the high side slightly twice because it was too rich in the air wide open and that's how I came up with the setting it has.



Since I'm pulling around a near 22 pound airplane I do use a fair amount of throttle, so I think the plug reading is fairly accurate.

 

[Lorne@pro-rc.ca]

Cool! either way that gp will pull that 22 lb plane around with authority :smile-new:

 

[nebwake]

Replaced the carb and all is well. Still not the easiest motor to start (compared to my DA 150 and 100L) but not a problem at all. Kinda funky to tune though. After talking to Kole, he told me that these carbs are built to be idiot proof... Meaning I cant tune it to save my life. The low doesnt change the low end like it normally does and the high takes a ton of adjustment to make a difference. Ill fly and tune it in the air but so far it sounds pretty good in the ground and best of all... the damn thing RUNS!!!!

 

[Bunky.F.Knuckle]

Glad you are on track! Just give it a little time to settle in. Don't tune the engine rich, as carbon fouling will happen. Slightly rich is ok.

 

[bbrown2828]

I'm loving mine it's going on its third plane a Redwing rc 89 extra

 

[gyro]

Is there any way to permanently attach a muffler? Not welding or anything, but any type of permanent sealant or something?