Author Topic: Tuned My NP2 Today PICS! (Read 16428 times))

NP2_Marksman · « **on:** December 13, 2014, 08:43:31 PM »

Ok so I was bored and decided to break down my newish np2 today and do a simple tune job (clean re lube etc..) So what I did was completely tear it apart and wipe everything down real good and then basically reassembled it with some moly

Piston seal looks fine.

However I upgraded the pivot point on the barrel and got rid of the old plastic washers and re installed some brass washers instead. What you need to do is go to the hardware store and buy two 5/16th brass washers. Now the outside diameter needs to be slightly ground down to fit. That's made simple by using a small pedestal grinder. Once it was the right size I drilled out three holes around the outside for better lubrication. I'm not sure how much it's going to help but I'm sure it's going to work better opposed to just having no holes.

Stock plastic washer vs brass ones

New and improved washers installed with some grease!

And I also played around with the idea of changing out the trigger spring for a lighter one so I also got a new spring and cut it down to size but it was too light. If I were to pull the first stage and let off the first stage wouldn't snap back. So I will order a CBR trigger soon and use that.

Original trigger spring on the right lighter one on the left

So after spending some time tinkering with it and re lock titeing everything my gun shoots a lot nicer. Better smoother cocking cycle and I feel that the velocity has raised a little. I will have to check with a crony soon. Put the scope back on and resighted it in at 30 yards with 15.89gr JSB's. Hope this info will be helpful to others.

Don't mind the two to the high right I was still re dialing my scope with those shots

dizzle · « **Reply #1 on:** December 13, 2014, 09:23:58 PM »

Turn the trigger adjustable screw all the way out. Mine did the same at first. What diameter is the piston? Either way that some nice grouping!

Privateer · « **Reply #2 on:** December 13, 2014, 09:27:53 PM »

That Gas Piston looks suspiciously like the same one the Nitro Venoms use.

LAalex · « **Reply #3 on:** December 13, 2014, 09:40:35 PM »

Nice Job. Good looking groups there. Thanks for the pics.

Scotty

DOKF · « **Reply #4 on:** December 14, 2014, 02:30:03 AM »

Nice job! Thanks for the pics.

woodbutcher · « **Reply #5 on:** December 14, 2014, 03:01:31 AM »

The piston seal looks good ,for a factory one ..!..

DOKF · « **Reply #6 on:** December 14, 2014, 06:22:52 AM »

Brian,

You inspired me to take my NP2 apart, and to give it the once over.

I also compared the works to that of the NV system. A couple points:

1. The gas rams are different for NV, NP XL, and NP2. The NP2 ram is actually slightly smaller than that of the NV system.
2. The Crosman diag shows the piston as a single unit including the seal and red shock absorber band, however the seal is replaceable with a standard 29.00 mm (1.14") OD seal (available from ARH in their Crosman Solutions Pack)
3 The piston seal dia is slightly larger than that of the NV system (25.4 mm or 1.00")
4. The piston length / throw is about the same as the NV system (sorry, I did not take exact measurements)
5. The piston does have 2 strategically placed buttons recessed in place, and it looks like the red shock band may also provide some centering assistance
6. The rear ram stop is a block of Al encased in the plastic end cap. Fitting the gun in a spring compresser is a PITA as the rounded plastic cap makes it difficult to get the clamp centered on the ram.

Other than the above, I was impressed with general condition of the piston, seal, and cylinder compared to what I saw in the NV twins. The seal on my gun was in good condition, so I thoroughly cleaned the system, lubed it all up and re-assembled the gun.

OldFlyRod · « **Reply #7 on:** December 14, 2014, 01:42:57 PM »

Brian, thanks for the pictures. I just took my NP2 apart. Other than being gritty, it showed no sign of wear except on one of the nylon balls on the piston is flattened out. No sign of metal to metal wear. The piston seal shows no sign of wear. I took pictures on my iPhone and need to figure out how to get them here. All you used was Moly grease to coat the cylinder? Can synthetic motor oil be used if I don't have any Moly?
Going to call Crosman, again, to see if they will ship me a few of them. Now I have to figure out how to remove and replace them

DOKF · « **Reply #8 on:** December 14, 2014, 02:51:11 PM »

Quote from: OldFlyRod on December 14, 2014, 01:42:57 PM

Brian, thanks for the pictures. I just took my NP2 apart. Other than being gritty, it showed no sign of wear except on one of the nylon balls on the piston is flattened out. No sign of metal to metal wear. The piston seal shows no sign of wear. I took pictures on my iPhone and need to figure out how to get them here. All you used was Moly grease to coat the cylinder? Can synthetic motor oil be used if I don't have any Moly?
Going to call Crosman, again, to see if they will ship me a few of them. Now I have to figure out how to remove and replace them

Motor oil would not be a good idea; it is combustible, and will lead to dieseling. Use Mo grease, readily available from ARH.

MIKELMIS · « **Reply #9 on:** February 12, 2015, 05:38:13 PM »

NP2__Marksman ,

Great post - I just got me a brand new NP2 Trail and wonder if there's anything it needs right out of the box? I sure would like to tune it but my last teardown on my Chinese gun ended in disaster and I'm not sure I want to void the warentee on this one .
Do you know anyone that tunes these NP2's ?

DOKF · « **Reply #10 on:** February 12, 2015, 06:30:52 PM »

The NP2 tune is actually quite easy. The gas ram comes out as a unit, and doesn't expand much. You still should use a spring compressor ...

Seals and grease from maccari readily available.

mobilehomer · « **Reply #11 on:** February 12, 2015, 07:31:29 PM »

To answer one question from another thread - MIKELMIS, the trigger in the NP2 is the CBT, Gene's is the CBR.
I hae a GRTIII in my NVD, but I like the CBT stock trigger just fine.
Now to ask a question on this thread - DOKF, which seal from Maccari?

NP2_Marksman · « **Reply #12 on:** February 12, 2015, 10:46:11 PM »

Quote from: MIKELMIS on February 12, 2015, 05:38:13 PM

NP2__Marksman ,

Great post - I just got me a brand new NP2 Trail and wonder if there's anything it needs right out of the box? I sure would like to tune it but my last teardown on my Chinese gun ended in disaster and I'm not sure I want to void the warentee on this one .
Do you know anyone that tunes these NP2's ?

Just the usual clean the barrel and break in is all you really need to do out of the box. However I did completely tear my gun apart and when it was apart nothing seemed to be rough or have any imperfections. I was quiet pleased to see that. The biggest mod I would say you can do is do the brass pivot washers and maybe a barrel crown. I also replaced the nylon guide balls on the piston with harder Delrin balls so they won't wear as fast. But as far as that the np2 is a great gun out of the box

DOKF · « **Reply #13 on:** February 13, 2015, 12:05:27 AM »

Quote from: mobilehomer on February 12, 2015, 07:31:29 PM

To answer one question from another thread - MIKELMIS, the trigger in the NP2 is the CBT, Gene's is the CBR.
I hae a GRTIII in my NVD, but I like the CBT stock trigger just fine.
Now to ask a question on this thread - DOKF, which seal from Maccari?

Gene was gracious enough to provide me with a CBR trigger. I got the "Crosman-Benjamin-Turkish- Chinese ETC. Seal Pack" and Mo lube from Air Rifle Headquarters.

I agree with NP2 Marksman that the pivot washers made the most improvement.

NP2_Marksman · « **Reply #14 on:** February 13, 2015, 01:24:01 AM »

One thing to add about the pivot washers is crank that screw down until the barrel can just barely be held in any position after its cocked. That has seemed to be the perfect tightness (I know technical term lol) it minimizes almost all the side to side play the barrel can have at the pivot point

Gear_Junkie · « **Reply #15 on:** February 13, 2015, 12:15:51 PM »

Great info and pics, thanks! I have a couple questions:

1. How much pre-load/pressure was there on the NP2 ram when you took it out of the spring compressor?

2. How far did the NP2 ram extend past the end of the tube when you removed the rear plug?

Thanks.

MIKELMIS · « **Reply #16 on:** February 13, 2015, 12:45:26 PM »

Thanks for clearing that up Ken

And thanks to all for your tips !
My new NP2 is filthy on the outside and the barrel is dirty as well .
I got high hopes for this gun as I turned in my Trail NP XL 1100 for it .

MIKELMIS · « **Reply #17 on:** February 13, 2015, 12:47:08 PM »

Quote from: NP2_Marksman on February 13, 2015, 01:24:01 AM

One thing to add about the pivot washers is crank that screw down until the barrel can just barely be held in any position after its cocked. That has seemed to be the perfect tightness (I know technical term lol) it minimizes almost all the side to side play the barrel can have at the pivot point

you would think that for a few cents more ........Crosman would just use the brass washers in the first place !?

OldFlyRod · « **Reply #18 on:** February 13, 2015, 12:58:47 PM »

Dokf, when you changed the factory piston seal with the Marcari did you feel any improvement? My gun and my ability to shoot it has settled down to the piont that I'm getting Marksman's groups, after a self tune and factury seal change. Still don't have a crony, but the gun is getting one shot kills at 20 yards on armadillos with head shots.

MIKELMIS · « **Reply #19 on:** February 13, 2015, 05:36:17 PM »

Once I got all the grease out of the barrel , I needed more then a few patches to get the RUST out !!
Then I shot it and so far the thing is SWEET !!

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Tuned My NP2 Today PICS!

Author Topic: Tuned My NP2 Today PICS! (Read 16428 times))