Problem- need help on my D48 sigh

[barcabarca]

  ok. I tried to install the zrt kit into my 48. all seemed well until I went to cock the rifle, now the sear won't engage.  the rifle will cock the spring but the trigger sear will not engage...

I did the following things:

1 took rifle apart
2 cleaned entire rifle out with alcohol
3 lubed up zrt kit with lubes provided
4 checked seal on piston with magnifier to make sure all was well: it was
5 took apart trigger and carefully polished the two key surfaces of the trigger sears identified in scott heath's tune of the 48.  I only used a dremel with a soft cone and polishing compound, not enough to take away any metal, just make em shiny
6 reinstalled all
7 tried to cock rifle, now the lever arm will pull back and the spring will compress, but it does not engage the sear



anyone else have this problem, anyone have any ideas why this might be happening   

thanks for any hints or insight...

[TOM aka critter99]

Was the trigger in cocked position when the group was installed???  release safety and try pulling trigger then recock

If not that the tophat or washer guide at back is slightly too thick

[TOM aka critter99]

http://www.network54.com/Forum/184474/thread/1326644000/I+have+a+question+for+M48+gurus+re-+Vortek+kit+-

[Kailua]

You might have to measure all the components.  Then measure space from inside the piston to where the rear spring guide sits when full cocked.  Makes sense the new components lined up are longer than the space given.

[barcabarca]

  Hey Kailua,

by measuring the components, do you mean take the tophat and spring guide kit and put them next to each other and measure the total length that the combined items make vs the total depth of the interior of the piston 

I just want to be sure im calculating correctly

thanks, 

[tjk]

Have you checked your cocking lever adjustment? When you change the power plant with new and different fitting components, it may be neccesary to make the proper adjustments to the cocking system as well. Hths

[Kailua]

I would line everything up and take a measurement.  Also figure the measurement needed with the rifle cocked.  I may also figure the length of the spring fully compressed into the equation.  Wire thickness times coils should give a compressed length.  Now this is where I would need help from an expert.  I think it was 5% added to the sum of the calculation. 
I hope tjk's advice works out would be a lot easier. lol

[barcabarca]

thanks all for the help so far...nothing has worked yet...

I have measured the guide and the tophat in the new kit and it is precisely the exact same length as the stock guide..

I have inserted the piston with the kit, minus the spring, into  the trigger assembly to make sure there was not an obvious reason that the trigger would not set, it works with both zrt kit and the stock guide so there is no real fit issue with the kit or seemingly, the trigger.I held the whole assembly up in the air and released the trigger, just to make sure that under some tension, it would release..it did.

I did notice that everytime I tried the zrt kit, the safety did pop out into the correct position, but the sear never seems to engage, the spring tension is only being checked by the beartrap mechanism each time. I have to carefully and firmly hold the cocking lever and then release the beartrap button, and carefully return the arm to the starting position.  You can feel the spring tension releasing as I return the arm to start.

I feel like I have eliminated the need to reduce the zrt kit dimensions, but I guess that it means that there is something wrong with my trigger reassembly

I will check my trigger reassembly, check the cocking arm and see if that makes a difference.  I am getting really good at taking this thing apart and putting it back together, I will definitely be much more knowledgable about putting this together as this will by my 8th time in the last 24 hours!!

 

[thekid]

Multiply coils times coil thickness on new kit, vs the Oem wire size times coils.
then add size of top hat and guide base to spring calculation.

Measure piston depth, from inside piston to the bulge at the end of the piston shaft. Your math from spring and guides must fit inside this area with still a few thousands of an inch room to prevent spring binding..... I think.