Cleaning GAMI injectors

Fearless Tower

Fearless Tower

Touchdown! Greaser!
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Fearless Tower
For those that believe you should never clean GAMIs, I figured I'd share this tidbit: When I bought my Baron, it came with GAMIs but I couldn't successfully run LOP (engines would run too rough with some cylinders still ROP). After doing nothing but pulling the injectors and cleaning them, I can now run LOP on all cylinders very smoothly.
 
My IA always pulls the GAMIs and cleans them at the annual.
 
I have no idea why supposed mechanics can't be bothered to read and follow the ICA information that the part manufacturer provides:

Maintenance: GAMI recommends removal and cleaning of the nozzles at normal
intervals of 100-200 hours. Nozzles may be soaked in an appropriate solvent such as
Gunk™ carburetor cleaner or Hoppe’s #9™ Gun Solvent, followed by blowing off with
an air nozzle. A small hole should be visually clear through the nozzle. Caution: Do
not attempt to insert any drill, wire or other article into the nozzle in an attempt to
clean the orifices. In the event that a nozzle becomes clogged and requires cleaning
and recalibration, it may be returned to GAMI for immediate service.​
 
I can't figure out why anyone would not clean GAMIs. The only word of caution is making sure they go back in the proper cylinder.
 
Ted DuPuis said:
I can't figure out why anyone would not clean GAMIs. The only word of caution is making sure they go back in the proper cylinder.
Click to expand...

Dunno, but it seems like the majority of folks at BeechTalk don't believe you should ever touch them.

At any rate, I'm glad I took your advice!
 
Fearless Tower said:
Dunno, but it seems like the majority of folks at BeechTalk don't believe you should ever touch them.

At any rate, I'm glad I took your advice!
Click to expand...

I believe that is the recommendation from GAMI. Unless your engine analyzer and/or your lean test show that your distribution is off, don't touch them. In your case, your distribution was off, so of course one of the first maintenance steps would be to clean the injectors.
 
Fearless Tower said:
Dunno, but it seems like the majority of folks at BeechTalk don't believe you should ever touch them.

At any rate, I'm glad I took your advice!
Click to expand...

Glad it worked!
 
I think folks don't want you to damage the things, so don't use a drill bit to clean it out (hoppes #9 works) and go for it.
 
I don't have GAMIs but my factory (Platinum series) is well balanced enough that the GAMIs probably will not help (they all peak within a 1/8 of a turn of my mixture knob) but don't let the mechanic scramble the order of them. I picked my plane up from annual and the thing just wouldn't lean right.

Me: Did you take my injectors out at annual?
Kevin: I cleaned them.
Me: Did you put them back in the right cylinders?
Kevin: You don't have GAMIs.
Me: Yeah, but the factory ones were balanced.
Kevin: OK, I'll fix it.

It was right the next time I went to fly the plane.
 
Well, I'm sitting here in Alva, OK, waiting for my #3 GAMI injector to soak/clean in solvent. I was seeing hotter temps (e.g., 410 vs. ~380 in the other cyls on climb out (1st several mins), and then it would cool off to normal if I reduced power; and running LOP, #3 would be the leanest/coolest. Clearly #3 is getting less fuel than normal. Difficult to confirm the cause, why this one is acting up vs. the others. After refueling here, knowing that #3 was running hotter than the others, about 100 ft above the runway, #3 went to no EGT at all; not running rough, just no EGT (JPI shows EGT went from 1400 F to 300 F in 6 seconds). Some trash or something blocked the flow. Stayed in the pattern. When back on the ground, the EGT returned at low power settings. I'm going to make sure to clean all of my injectors every annual (don't think that was done the prior two annuals), but there's been no indication of a problem until the last 2 flights.
 
I don't have GAMIs but do run LOP with stock injectors. Clean them at every annual. Approx 100-150 hrs annually. Use Hoppe’s 9 Gun Solvent then mineral spirits, then blow them dry. Works well.
 
I use hoppes in a little jewelry cleaner from HFT designed for the purpose. Smells pleasant, so doubles as a hangar "pine tree" air freshener :)

I limit the clean to a few minutes as I understand the hoppes can attack the injector brass? I rinse them in 100LL before reinstalling into position.
 
GAMI recommends AGAINST cleaning every annual. Their contention is the most common reasons, that they see, for clogged injectors is fibers from shop rags.
 
For years I have never allowed a shop rag near any engine or fuel system that I was building or serviced.
Seems like common sense to me.
 
I prefer the minty fresh scent of Balistol myself.
 
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