Poly Tube Mod - Poor Results on 2289?

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rouf · #1 Post by **rouf** » Fri Nov 11, 2005 9:42 am

Hi,

I changed my transfer port last night on my 2289. I was really excited to see this vast improvment that everyone proclaims, but it actually made my gun weaker!! Here's what I did:

1) Use a 1/4" drill to make a seat for the poly tube on the barrel port
2) Use a drill that matched the inside diameter of the poly tube to enlarge the port in the barrel
3) Use the same drill to enlarge the exhaust port on the valve
4) Dremel the inside of the exhaust port on the valve to provide a tapered port
5) Fit a piece of poly tube between the exhaust port and the barrel
6) Reassemble and retest

Now instead of going through 80 pages of my phone book with 8 pumps, I am going through 57 pages. I can actually dump 13 pumps now, but even at 13 pumps, I only go through 77 pages. So, for the price of 5 extra pumps, I get the benefit of losing 3 pages of power...

What could I have done wrong?

Thanks,

Chris

jezX · #2 Post by **jezX** » Fri Nov 11, 2005 10:05 am

the only thing i could think is the tubing may have squished into the valve to far . or the barrel ,and is blocking the air . what was the id of the tube ? and how much did it squish putting the barrel on?

#3 Post by **sniper** » Fri Nov 11, 2005 10:10 am

Yes, agree with JezX, that's what usually happen, sometime when cutting the tube got to make sure it's a straight cut too, well depends how the drilled port hole is on the barrel, everything got to line up perfectly so no air gets block or leaks.

rouf · #4 Post by **rouf** » Fri Nov 11, 2005 10:11 am

I can't remember off hand the inner diameter. It's the 1/4" poly tube from Canadian Tire. I didn't really squish it when I put the barrel on. It fits snug, but I didn't have to squeeze it down. Could this be the problem?

Thanks,

Chris

airsmith282 · #5 Post by **airsmith282** » Fri Nov 11, 2005 10:21 am

if the gun before all this went through 80 pages at 8 pumps that is dam impressive i would have stoped there my self you cant expect to much more then that from a pumpup gun....perhaps you shoud have gone 10 pumps. after plugging the bleeder you can goto 10 pumps.. i think you might want to get the valve i had mentioned before slap it in and now that the barrel is modded get a new barrel and start over...but put in all the factory parts except the valve use the 1322B013 valve insted...
and take it to 10 pumps or even 15....and for penatration use pointed pellets either crosman pointed or rws super point pellets would work best....

rouf · #6 Post by **rouf** » Fri Nov 11, 2005 10:41 am

It dented to 80 pages. I'll have to look to see how many it tore. I was shooting pretty close too. I stood over the book, and shot down, so that I would always be shooting from the same distance.

Chris

TCooper · #7 Post by **TCooper** » Fri Nov 11, 2005 12:49 pm

As was said, the tubing must be the correct length. Several years ago I was experimenting with a Cr2240 pistol and poly tubing. I chopped a piece and it seemed to fit snugly but what was actually happening was the tubing was bending sideways a bit when I installed the breech. This resulted in poor flow and poor velocity. I kept chopping the length until things worked properly. Tubing is cheap so keep experimenting with different lengths until you get it right. It has been done successfully before by other shooters.

If the bleed hole in your valve is plugged then you should be getting approx 460ish with 14.3gr pellets. Someone here did this single mod and posted the results here.

Todd

TCooper · #8 Post by **TCooper** » Fri Nov 11, 2005 1:22 pm

A few more good threads to read:

Here is an old forum posting about a modded Canadian 2289 that could be pumped 20-50 times and hold air.
http://www.airgunforum.ca/forum/viewtop ... -2289.html

Sniper's Canadian 2289 would do 449fps at 8 pumps.
http://www.airgunforum.ca/forum/viewtop ... -2289.html

Here is a posting about a Canuck 2289 going from 400fps to 465fps with a bleed hole filled.
http://www.airgunforum.ca/forum/viewtop ... -2289.html

Another good thread
http://www.airgunforum.ca/forum/viewtop ... -2289.html

and
http://www.airgunforum.ca/forum/viewtop ... -2289.html

Todd

Steeb · #9 Post by **Steeb** » Fri Nov 11, 2005 1:56 pm

Definately the poly tubing works. Todd is right about getting the length correct. The same thing happened to me with having the poly tube cut just a bit too long and it would squish under the breech. But once you get the tube length right and sealed with no leaks. The power difference will be very noticeable. Big big, boom boom!

And you shouldnt feel any breeze or co2 leak on your shooting hand.

rouf · #10 Post by **rouf** » Fri Nov 11, 2005 11:39 pm

Thanks to you folks, I got it working great. It turns out that I had cut the tube a wee bit too short, so it wasn't squished at all. Now that I fixed it, the gun is working amazingly!

Results: Before the poly-tube mod, put a visible dent through 80 pages of the phone book. After the mod, it put a visible dent through 167 pages!!!! The second shot after the mod did 122 pages. No matter how you look at it, it was an amazing improvement.

As for my other test, I was shooting at a board from 4m and 8 pumps:
1) Before sealing the bleeder hole, 0.205" deep hole
2) After sealing the bleeder hole, 0.215" deep hole
3) After the port mod, the pellet is in there so far I can't get it out, but it looks like it went most of the way through a .75" board.

Thanks again for all your help!

Chris

p.s. with all due respect airsmith282, I am the type of person that likes to tinker with things. Buying new parts is a last option for me, if I think I can make what I have work better. If I ever need parts, I'll look you up

TCooper · #11 Post by **TCooper** » Sat Nov 12, 2005 11:28 am

Hi rouf,

Does the Canadian 2289 manual state 8 pumps or 10 pumps for maximum? I think the American version states 10 pumps.

I'm glad you got things working properly without buying unnecessary parts. The mods were successfully done before so they can be done again.

Thanks for keeping us updated.

Todd

#12 Post by **webstien** » Sat Nov 12, 2005 11:41 am

is it necessary to drill the barrel to 1/4" inch for the poly tubing? I have a steel breech coming soon and im probably going to do this mod.

IF anyone remembers the exact poly length used for a crosman steel breech I'd like to know what it is, just for reference.

#13 Post by **sniper** » Sat Nov 12, 2005 2:23 pm

webstien wrote:is it necessary to drill the barrel to 1/4" inch for the poly tubing? I have a steel breech coming soon and im probably going to do this mod.

I would do it so that poly tubing sits on flat surface and secure, less chance of leakage.

webstien wrote: IF anyone remembers the exact poly length used for a crosman steel breech I'd like to know what it is, just for reference.

Do your own measurement is better according to your gun.

jezX · #14 Post by **jezX** » Sat Nov 12, 2005 7:06 pm

if you don't drill the barrel you can heat a rod the size of the barrel and form the tubing or heat the tubing and form it .solder iron _. this works well.not as good as a 1/4'' endmill
the length of tube depends onhow far you drill into the valve and how far in to the barrel . prolly 1/4'' long

SubaruBen · #15 Post by **SubaruBen** » Mon Jul 31, 2006 10:14 am

how did you guys cut the tubing flush? i keep using a blade and everytime the ends are like uneven.

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Poly Tube Mod - Poor Results on 2289?

Poly Tube Mod - Poor Results on 2289?

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