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twalter · Veteran Member

Ive recently began to have a dieseling issue. Backstory is...

I have the gamo hunter 220 and back in the fall I cleaned the barrel by pulling patches with a snake and used simple green as the cleaning agent. This sent my accuracy all over the place and took care of dieseling for short period of time. I cleaned it a few more times in the same manner till I though I got all the gunk out of the barrel. Thing is it started to get cold and stay that way and on top of that I was keeping it in the van under some blankets always at the ready to go if I was out and about with some time to kill. Once in a while when it would warm up I would get a serious cook off then I would go back to no dieseling. I have recently moved from NY out to NV(elevation change of 5050 or so) and now this thing diesels on every shot again and the pellets are behaving erratically. It goes without mentioning that it is much warmer out here also.

Now to the point of my rambling... Im guessing this grease/oil is coming from the spring/seals area of the rifle and to get rid of it Im going to have to tear it down and clean it out. Im not sure which paste/tar to use and looking for suggestions and while I have it apart what spring and seal kit would be good to have on hand?

radar · Silver Status Member

Yeah, sounds like the grease/oil is running in the heat and getting into the compression area, I agree.
I usually just go to Jim Maccari's air rifle headquarters website and snoop around for seals and springs and stuff that fits. That's where you'll find spring tar and moly paste lube, too.

cheers,
Rob

twalter · Veteran Member

Basically wanted to speak it out and get confirmation, thanks. I was also fishing for the Jim Maccari's website that I had forgotten to bookmark a while back.

radar · Silver Status Member

Ya. Search under Air Rifle Headquarters.

shawnhu · Member

Hey Walt! Nice to see that you are settling in after the move, and getting some shooting in. Sorry to hear about your problem, but what exactly is dieseling, and how can I go about in checking if I have this problem?

twalter · Veteran Member

Thanks Shawn. Its was nice to finally get out and do some shooting. I have a good Army friend that lives over the the Ca side of the Serria's and he was all stoked to take his AR and .22 out and blast away. We happened upon a NPSS that was on sale for 250 in .177 and needless to say he picked it up. We have it sighted in and the magic pellet seems to the be the 8.44 JSB's. He now leaves the AR and .22 at home when he comes and we have shoot arounds with the air rifles. Last time we were shooting off rocks for rests and hitting rimfire .22 rounds we found in the dirt @ 25 yards. He is now a air gun convert, ground squirrels beware!

I almost forgot, dieseling is when grease gets in the barrel or in front of the seal area and you "cook" one off. You see the smoke hanging in the barrel usually after a nasty diesel.

domer_pyle · Senior Member

Diesel engines don't use spark plugs, they get combustion from quick compression. Hence the term "dieseling". I get the same thing with some of my springers when it gets hot outside. Usually not enough for a report but the smoke lingers in the barrel

shawnhu · Member

Hmm, I get that almost every shot.... smoking gun effect. Usually more noticable once I open the barrel to load another pellet. What's the fix?