Question about RTO PasLode 900420 Impulse Framing Nailer

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Paslode Framing Nailer Repair

I disassembled the gun to clean and repair, I can't remember what position the pins (404827) go in respect to the spring (404411). Do they slide through the spring at the end near the bumper or midway through the spring. I also haven't been getting spark, I had to replace the wiring harness (900475) due to one of the contact ears breaking off. I bought the gun used and I haven't been able to get it to fire yet. Should I replace the spark plug or the entire spark unit assembly, how often do the assemblies go out and is there any way to test the assembly. Thank you. Jason.

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  • jpmach1 Jan 26, 2009

    Thanks for the help Rowdy, I did as you said with the spark situation and I still do not have any spark. The LED and fan work, but no spark. I need to check the continuity of the wire, it looks fine but I'll check it tomorrow. Do those pins go through the end of the spring near the bumpers or should I push the assembly together and put them about midway through the spring? I bought the gun for $60 at an auction I figured I can put some money into it and still be ahead, hopefully not too much cash though. Thanks again rowdy.


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Hi jason hows it going m8. right first of the rebuild u should have 3 main parts combustion chamber 404407, upper probe 901249 and nail chamber 404436. first place 901249 the 2 springs and the rubber stops onto 404436, put some paslode oil around the oring at the top of this part then slide the assembly inside 404407 hold the 901249 upper probe and push it up u should be able to put the pins through they don't touch the springs they go under the lugs at the top of the upper probe. now to get it fireing with the barrel assembaly of the gun you should be able to see the fan now be carefull as this can be dodgy. if u look at the moided circuit assem 900475 u will see a switch at the top this tells the gun its ok to fire its a saftey switch. if u put a battery in the gun and carfully hold down this switch mind when u hold the switch down the fan will start then pull the trigger u should see a spark at the spark plug assembaly if not unplug the pink wire and hold a screw driver next to the plug. if you get a spark great if not check the pink wire going to the spark plug is ok and pushed firmly into the spark unit 900474. this should solve your problems and hope i have helped. let me know how u get on with the gun.


Posted on Jun 24, 2009

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Hey rowdy45176

ive got a kink in my pink cable to the spark unit i can it clicking but cant always see a spark and never fires was wondering what u thought ???

Posted on Mar 04, 2010

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I have a paselode finnish nailer im250-f16 11, when applied to wood surface and trigger pulled the gun does nothing, fan will not go on or shoot a nail. I cleaned the gun and still nothing, need help thanks.

Posted on Nov 30, 2009

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Check to see if the red wire going to spark assembly is loose. You must hit the top head swirch and then the trigger switch in that order to get a spark. Do you need a parts breakdown?

Posted on Jun 30, 2009

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The pins you refer to go in after you push up on the yoke that connects to the work contact. What you need to do is put the bumpers on top of the sleeve you will see where they sit and the springs on either side holding them in place with one hand so they don't go flying and push the sleeve assembly into the combustion chamber, you might have to push up on the yoke some so it fits or squeeze it as it enters. Push this assembly and while holding together put the pins in either side. Them what I do is pull them apart so make sure the unit retracts properly. Now for the spark, you replaced the electronic unit and no spark, You want to make sure that all the wires and connectors are properly inserted including the spark plug wire. With the unit apart insert battery and watching out for fan pull the trigger, the fan should run and go off after a few seconds. Then you will see under the motor/top area a roller and lever push on the lever, again watching out for fan and it should do as above, Now to check the spark unit push and hold the roller lever and squeeze the trigger and you should see and hear spark. release all these and do again. If no spark it could be the spark unit (around 90.00) or the wire could be bad. These spark units are designed to last a long time. If you bought this used I hope that the person was not a friend ( just kidding). Let me know what happens

Posted on Jan 23, 2009

  • David Ford
    David Ford Jan 29, 2009

    When you push the sleeve into the combustion chamger they go on the outside of the rail that connects to lower probe.. Check for a break in the wire that would go to ground on the spark unit and also look at the plug for a crack allowing the spark to ground. Good luck


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