Author Topic: Benjamin fortitude. Can't get reg, gauge block ect back in tube. (Read 1817 times - 1 votes)
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kimmons · « **on:** April 13, 2020, 08:03:32 PM »

I'll start by saying I haven't done a lot of this. However, I have taken apart my Marauder apart several times and done the SSG mod. It wasn't hard to get back together.

I read a thread on here by FuzzyGrubb and posts by mobilehomer regarding generation two fortitudes, so I opened mine up. I opened up the valve port and adjusted my regulator 5/8ths of a turn ccw. I bought a small set of files and tried to deburr the tube. For the life of me I can't get a single o-ring back into the gun without messing it up. I'm using #40 and #11 O-rings from home depot. Any help is appreciated.

mobilehomer · « **Reply #1 on:** April 13, 2020, 08:17:44 PM »

Use ample silicone grease on the o-rings. Plumbers grease, divers grease, Superlube grease, dielectric grease, whichever is easiest for you to obtain. As you push it into the fill assembly threads, go slow and work it in, not in a hurry. When you get the o-ring near the gauge hole, SLOW DOWN and using a finger, small screwdriver or what you have to compress the o-ring as it goes past the gauge hole. This is the critical section. As I am not the best at this, I still take anywhere from one to five o-rings to get one reassembled. Take your time and know you are not alone in slicing o-rings.
Before reattaching the trigger, hammer, end cap,breech and anything else, I pressurize and submerge the bare tube to check for leaks.

csitas · « **Reply #2 on:** April 13, 2020, 09:01:47 PM »

I don't know how far you went working on the tube but, I 'd suggest you might not have the slots polished down enough.Maybe hit it with 400 grit wet or dry , then go to 600. Should not have much trouble with a greased Oring after that.

FuzzyGrub · « **Reply #3 on:** April 13, 2020, 09:38:59 PM »

I don't know those Home Depot part numbers. The O-rings on the air tube parts are -113 and -016. BunaN in 70D are good. I don't suspect it, but if you try 90D O-rings they will be extremely hard to get into the tube.

Along with the gauge hole, the trigger assy screw hole needs deburring. Ball hones is what I use.

I put black marker on each part to watch and make sure the part doesn't rotate too far as the parts are pushed in.

Before starting, I use silicone oil liberally on the inside of the tube, to help the parts slide easily. I liberally use grease on the fill threads for each part. It can take some effort to get the O-ring over the initial ledge. I use a 3/4" diameter wood dowel rod to push valve, reg, gauge block, etc. I wiggle, rotate, the pressure on the part to get the O-ring over the edge. Once past, push it slowly toward gauge hole. Before getting to it check the rotation. If need be, push it back out, and try again. You can also rotate parts when at the gauge hole with a pick, but be careful.

For the gauge hole, I use to use the flat part of screw driver to compress the O-ring as it goes under the edge. I now use the tool below, and it works great.

https://www.@#$%^.com/Gauge-Port-Filler-Tool-for-Benjamin-Marauder-p/mrodfillertool.htm

Note: the link will not work due to GTA rules and issue with this supplier, some years ago. They are the only one I know of that has it.

Zarcher Airguns, remove Z. Hopefully, I don't get in trouble for this.

kimmons · « **Reply #4 on:** April 13, 2020, 10:50:33 PM »

Guys, thans a lot for the tips. I'll try again tomorrow! Matt PS do I have to worry about polishing spots inside the tube...the lip at the fill end is sharp.

FuzzyGrub · « **Reply #5 on:** April 14, 2020, 02:28:30 PM »

Quote from: kimmons on April 13, 2020, 10:50:33 PM

do I have to worry about polishing spots inside the tube...the lip at the fill end is sharp.

If you can break just the leading edge of the lip, that would be good. Be careful, you don't want to scratch the tube where the O-ring in the fill assy seals against. If the threads are real sharp, I have used a little cleaning up with 400 grit. Clean tube very well after any deburring.

kimmons · « **Reply #6 on:** April 14, 2020, 03:33:45 PM »

I finally got it back together. It shoots slower now than it did before I started :-(. A 2800 PSI it's only shooting about 610 feet per second. But then when it gets down to about a thousand psi's it shooting about 730 ft per second. It's behaving like it's Unregulated?

I am sure I originally turned the regulator counter clockwise 5/8 of a turn. However once I pushed it down the tube it wasn't lined up and I had to find a way to rotate it by using an extension and 1/4 inch driver. I'm reasonably sure the regulator spun in the tube because I could see it moving. I don't think it changed the adjustment. It was lubed up really good. But that's a possibility.

Secondly on my Marauder I was sure there were two of those small rubber grommets, one on each end of the aluminum part that goes between the air cylinder on the breach. I was really careful opening my fortitude up. I only saw a grommet on the air cylinder side. I didn't see one on the breach side. I could have lost it but I don't think so. Also the aluminum cylinder has a longer neck on it on one side I'm assuming that longer neck is the one that goes up into the breach without the seal. Can anybody confirm this? I was hoping to get the 850 with some heavier pellets like the 18.1 jsb.

It used to shoot about 720 ft per second or very close to that with JSB 15.89

FuzzyGrub · « **Reply #7 on:** April 14, 2020, 04:11:29 PM »

The transfer port only has a seal on one end. It goes against the valve side. It is just a mechanical fit on the barrel side.

I'll defer to Ken who has done this on a near stock Fortitude, but offhand 5/8 turns seems like too much to me. The adjustment does turn very easily, so that might have happen. Shoot a string so you can tell where its coming off the reg.

Did you open up the transfer port (ID)?

PS: The picture above is for a Gen 1. It may have changed in Gen 2. I haven't taken a Gen 2 apart yet.

mobilehomer · « **Reply #8 on:** April 14, 2020, 04:22:38 PM »

Seems to me it has a seal on both ends. Mine does now, anyway.

I THINK I went about 5/8 turn. Mine did spin in the tube so I don't really remember. Check for a leak at the TP while shooting. Use just a tad of talcum powder or flour on the junction between the breech and tube at the TP while firing. There does need to be a pellet. If no leak, then adjust about 1/8 turn CW.

kimmons · « **Reply #9 on:** April 14, 2020, 04:58:37 PM »

Mobilehomer, that's cw clockways, not ccw. Correct? You think I might have gone to far?

Fuzzygrub I only opened up the valve body to match the transfer port. I opened up the valve body to about. 135—+

PS. Is there a fast way to degas without the tool?

FuzzyGrub · « **Reply #10 on:** April 14, 2020, 05:16:35 PM »

You need to shoot it down to find out where the reg is. It can be too high, and you are partially valve locked or just way too low. If you have the tool, that is about the easiest.

kimmons · « **Reply #11 on:** April 14, 2020, 06:44:12 PM »

Changed ammo to chps. Because I had a couple tins and it's cheap.
I only put it to 2800 because that's all my tank had.
I backed off the regulator clockwise 1/8th of a turn. I can look down the tube and see it and the mark I made. It hadn't moved, it was right at 5/8 where I left it prior to this adjustment . Right now it's just a little bit over half. All shots with Factory hammer spring adjusted to the max just before where you can no longer cock it . That was a lot of shooting, could I have started lower?

684. 2800
697
701
704
716
703
707
707
702
692
717
716
717
715
716
721. 2500
721
721
721
719
715
719
714
717
725
721
725
718
721
725
718
720. 2250
714
724
724
727
722
720
734
733. 2100
742
749
748
753
759
759
767
761
768
779
776
780
788
784
793
799
784
794
793
802. 1750
794
805
804
806
806
806
804
801
807. 1500
798
798
802
799
791
790.1400
784
785
783
765.1350
769
762
752 1150
756
752
738
728
720.1000

FuzzyGrub · « **Reply #12 on:** April 14, 2020, 09:28:45 PM »

If I saw the request before you ran the string, I would have said just fill to around 2200psi. But, I wouldn't have seen the large creep (100fps) from 2800 to 1800psi. Were you seeing a rise like that prior to your mods? Do you have a before string with the hammer spring close to the way you have it now? I suspect some is due to hammer spring turned in so far. I'd like to see another full string with the hammer preload reduced. I think the stock setting is 4 turns from full CCW.

Draw a small star on your target and see if you can shoot all of it away like the old carnival days. Trying to help with those long, boring string.

PS; Were you able to perform the TP leak test?

kimmons · « **Reply #13 on:** April 14, 2020, 11:04:55 PM »

I should have taken a baseline before starting but I didn't. If I remember correctly it was so consistently boring the nearly all shots were around 720 ft per second. I didn't crony a lot though. Previously I was shooting it with a hammer spring set screwed in as far as possible, you know for more power :-).
How adjust the hammer spring for your direction and log another string. Do I need to start a 2800 PSI? PS I did perform the leak test and there is no leak.

kimmons · « **Reply #14 on:** April 15, 2020, 04:18:12 PM »

cphp 4 full turns from full CCW.

536 2750
559
556
556
560
561
557
561
559
534
570
552
568
568
552
569
565
563
560
571
557
569
585
579
569
568
579
574
575 2500
577
569
577
577
582
575
580
578
573
568
566
566
571
570
576
582
578
580
581
rest
557
567
574
567
583
585
577
585
595
602
597
603
613
616
622
631
635
633
634
640
644
652
652
654
665
671
671
672
676
680
679 2000
686
687
694
696
698
708
707
709
712
715
716
720
726
732
737
738
742
750
740
755
747
754
757
765
765
772
768
777
774
773
778 1350
774
770
771
767
768
764
756
753
754
756 1000
747
742
734
720
715
705
698
683
669 800psi.

FuzzyGrub · « **Reply #15 on:** April 15, 2020, 04:44:51 PM »

Well that was worse! Over 200fps rise

If you marked the starting position on the reg, I'd go back to it. And rebaseline.

If not, I'm guessing it is too high, and would turn it down CW a quarter turn. It might take a few iterations. I hate not having a gauge on the plenum.

kimmons · « **Reply #16 on:** April 15, 2020, 04:49:28 PM »

Thanks for your reply. I did mark it. I'll go back and rebaseline with 4 turns from CCW and original reg setting. My bolt hand is getting tired :-). I'll do another string and post back after I rest up. How can I tell where the reg drops off?

FuzzyGrub · « **Reply #17 on:** April 15, 2020, 05:16:45 PM »

Quote from: kimmons on April 15, 2020, 04:49:28 PM

How can I tell where the reg drops off?

That's part of the problem right now. It's hard to tell. You have something similar to the light gray line in bottom graph.

https://hardairmagazine.com/reviews/fortitude-gen-2-hammer-spring-adjustment/

kimmons · « **Reply #18 on:** April 18, 2020, 05:26:39 PM »

I finally got my crony in a phone to get along. This is a quarter turn counter-clockwise from factory (reg) , and 4 turns hammer spring from full ccw. with valve/transfer port .135

Should I turn it all the way back to factory and shoot once more for a Baseline. I figured I'd have to do this twice anyway so I thought I'd at least send this string for now and see if it was helpful.

Created: 04-18-2020 03:49:56 PM
Description: 3 fortitude .130 1/4 ccw reg
Notes 1:
Notes 2:
Distance to Chrono (FT): 0.00
Ballistic Coefficient: 1.000
Bullet Weight (gr): 0.000
Altitude (FT): 0.0
Temp: 63 °F
BP: 1019.00 inHG
Shots
# FPS FT-LBS PF
97 701 0.00 0.00 850 psl
96 706 0.00 0.00
95 716 0.00 0.00
94 728 0.00 0.00
93 729 0.00 0.00
92 736 0.00 0.00
91 739 0.00 0.00
90 740 0.00 0.00
89 749 0.00 0.00
88 753 0.00 0.00
87 755 0.00 0.00
86 754 0.00 0.00
85 757 0.00 0.00
84 758 0.00 0.00
83 764 0.00 0.00 1250
82 770 0.00 0.00
81 769 0.00 0.00
80 768 0.00 0.00
79 768 0.00 0.00
78 763 0.00 0.00
77 764 0.00 0.00
76 768 0.00 0.00
75 762 0.00 0.00
74 761 0.00 0.00
73 769 0.00 0.00
72 759 0.00 0.00
71 758 0.00 0.00 1500
70 ERROR 3
69 751 0.00 0.00
68 748 0.00 0.00
67 750 0.00 0.00
66 742 0.00 0.00
65 748 0.00 0.00
64 744 0.00 0.00
63 742 0.00 0.00
62 732 0.00 0.00
61 726 0.00 0.00
60 730 0.00 0.00
59 727 0.00 0.00
58 727 0.00 0.00
57 729 0.00 0.00
56 720 0.00 0.00
55 723 0.00 0.00 1800
54 688 0.00 0.00
53 705 0.00 0.00
52 694 0.00 0.00
51 690 0.00 0.00
50 702 0.00 0.00
49 707 0.00 0.00
48 712 0.00 0.00
47 697 0.00 0.00
46 702 0.00 0.00
45 705 0.00 0.00
44 702 0.00 0.00
43 700 0.00 0.00
42 705 0.00 0.00
41 699 0.00 0.00
40 699 0.00 0.00
39 696 0.00 0.00
38 700 0.00 0.00
37 707 0.00 0.00 2000
36 695 0.00 0.00
35 691 0.00 0.00
34 702 0.00 0.00
33 697 0.00 0.00
32 694 0.00 0.00
31 686 0.00 0.00
30 696 0.00 0.00
29 692 0.00 0.00
28 696 0.00 0.00
27 701 0.00 0.00
26 705 0.00 0.00
25 703 0.00 0.00
24 696 0.00 0.00
23 694 0.00 0.00
22 689 0.00 0.00
21 700 0.00 0.00
20 708 0.00 0.00
19 695 0.00 0.00
18 702 0.00 0.00
17 700 0.00 0.00
16 705 0.00 0.00
15 700 0.00 0.00
14 693 0.00 0.00
13 691 0.00 0.00
12 673 0.00 0.00
11 698 0.00 0.00
10 699 0.00 0.00
9 695 0.00 0.00
8 696 0.00 0.00
7 ERROR 3
6 693 0.00 0.00
5 693 0.00 0.00
4 688 0.00 0.00
3 680 0.00 0.00
2 683 0.00 0.00
1 692 0.00 0.00 2700
Average: 718.25
StdDev: 27.60
Min: 673
Max: 770
Spread: 97
True MV: 718.25
Shots/sec: 0.09
Group Size (IN): 0.00

FuzzyGrub · « **Reply #19 on:** April 18, 2020, 05:55:01 PM »

That is allot more consistent from fill down to 1800psi. I think it is coming off reg there. Rises and drops back down.

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Benjamin fortitude. Can't get reg, gauge block ect back in tube.

Author Topic: Benjamin fortitude. Can't get reg, gauge block ect back in tube. (Read 1817 times - 1 votes) )

Author Topic: Benjamin fortitude. Can't get reg, gauge block ect back in tube. (Read 1817 times - 1 votes)
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