Canadian Airgun Forum

But with a weak hammer spring, I doubt it will retain air and OP can shoot twice without re pump the gun?! But air was cleaned out each time....

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~Plinkers~
FX-M3-22 Compact#PP700-Carbine#Diana48-177#XS28M-25@26fpe#HW45 Beast#AW-Custom Z-Killer DE
~Competitors~
FWB300SU#Tau-7#IZH-46M#FWB-65#CP88-C
~Target~
HW 30s/35e/97k/40+Extender/P3+Scope/70#CZ200s Laminated@10fpe#AA ProSport-177@12fpe

If the problem related to the sear, is that means while pulling the trigger, the hammer was not released completely at once, but had some 'hiccup', so the valve was opened a little then fully opened so some amount of the air 'leak' into the barrel before the full power coming?!

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_________________
~Plinkers~
FX-M3-22 Compact#PP700-Carbine#Diana48-177#XS28M-25@26fpe#HW45 Beast#AW-Custom Z-Killer DE
~Competitors~
FWB300SU#Tau-7#IZH-46M#FWB-65#CP88-C
~Target~
HW 30s/35e/97k/40+Extender/P3+Scope/70#CZ200s Laminated@10fpe#AA ProSport-177@12fpe

Here a link to a flat top piston http://www.canadashootingsupply.ca/1377 ... -blue.html

The piston has to be adjusted to the valve! I've bought a few different flat top/valve assemblies from different suppliers and all
have sent instructions on how to do it.Please post some pictures of what you have so we can help you out.

OP, where are you located?

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Walter

Don't really care for that ftp design, but have heard that the newer plastic pistons are a lot stiffer now than they used to be. That was half the reason for replacing them before...they would flex under pressure and reduce the maximum pressure a fellow could reach...the metal ones don't. If you're pump handle stays up after you shoot, the piston IS making contact with the valve, there's no clip to hold the handle up on the 13xx/2289.

Ran across a curious 2289 a couple weeks ago that was shooting low with a ftp as well.

It's sort of like coming across a hammer that won't put a nail in...a curious thing.

Pumping it a few times showed that his gun simply would not build pressure the way it should. Tore it down and looked at the pieces. Everything looked okay, the tube was nicely de-burred, the o-rings were in good shape and the ftp was brass and adjustable...and making contact with the valve.

Tore my own 2289 down and tried his valve in my tube...would not build pressure.

Tried my valve in his tube...sealed up and built pressure...(although not like it does in my tube..found this out later)

Pressurized his valve with my air hose and sprayed it with soapy water..no bubbles @150psi.

Then changed out his valve stem for a delrin one, filled the valve with transmission fluid (red) and tried pumping it. Any leaks in his valve would have pushed the transmission fluid out (although not as easily as air), where a wipe with paper towel would show the color...and source of leak. The valve is not cracked or leaking. Cleaned it out and put his valve stem back in.

Put some 30wt oil in ahead of the piston and tried pumping it...major increase in pumping effort from previous, and started pushing oil out the hole where the front grip screw goes...BINGO. (Did push a bunch of oil into the valve...had to clean it out again)

Took a hard look at the o-ring groove on the valve and could not find anything wrong with it. It has the same id and groove width as my valve...within roughly .0005"

As far as I can figure, the only thing left is that there is a build up of tolerances between his valve and his tube that are allowing the leak...may have to change both parts.

Good luck with it,

Al

windsor, Ontario, it is in essex.

i posted a link here already, but there it is. https://www.ebay.ca/itm/Flat-top-ported ... 2749.l2649

Like the oil was coming out of the hole in the tube? or like the threaded hole in the valve?

i put my 1377 trigger assembly on the 1322. same issue.

I just need the piston.

Hole in the tube, yes. Its right behind the valve body o-ring when the valve is installed.

Al

I haven't seen it yet with a 13-XX tube, but a ftp in a 2100-2200 tube will distort the tube if it's over pumped. First signs of this are elongated pivot pin holes at the end of the tube. If the pumping bit is over done enough, the pump arm will start to distort and bend. In extreme cases, the pivot hole in the pump arm will elongate to the point where the gun will not build up adequate shooting pressure.
I did run into that one on a 13-89, which was a slightly different pump arm configuration...

Just a heads up not to push these platforms too far. They were designed for 8-10 pumps. I feel I can get away with 15 pumps max before I start placing undue stress on the under designed components. In fact, for most of my pumper situations, 8-10 pumps actually fills the bill quite nicely- especially with a well adjusted FTP....

-D.S.

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"Ain't no half-way"
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how about a bent pivot pin?

There have been a few soft ones. I've only seen one, and they are easily replaced.

-D.S.

_________________
"Ain't no half-way"
-S.R.V.