Metal gearbox problems

howdy guy i have the metal gearbox that chainsaw products is selling in my slr and i have fitted a wells nozzle and slr tip for it and after a few shots it come of the tappet any ideas on how i can fix this issue

Did you use a wells tappet ?

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No i havent just using the stock one

The stock one won’t fit the wells nozzle

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Will a gen 10 tappet work and can i put the gen10 nozzle in it

What t piece are you using ?

Stock slr and ik it will work with the nozzle was using before i got the netal gearbox

So i tryed it it feeds but has low fps i used get 280 also it isnt feeding consistently

For best results if your using a Wells nozzle, you need to match it to a wells cylinder head and then a wells cylinder which is slightly shorter than than the standard APS cylinder.
Also you need to use a 6 mm well’s tappet plate and mill about 0.5 mm of both sides of the tappet plate to make it run smoothly in the APS box. Also you need to dremel about 5 mm off the the APS box in the front of the tappet guide so that you get full tappet travel.
It sounds like a lot of trouble but it really isn’t that hard and well worth the effort.

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I’m pretty sure a Gen 10 tappet is to long for the APS box, but you could grind some off the back of the cam lobe but not recommended.
Basically you need to put in a longer cylinder head like the well’s to give you the needed tappet travel.


I’m guessing you got one of the older APS raw box’s from Chainsaw. The new ones look like they are fitted out with similar internals to the ones in the MPX and Titan blasters.
These have total custom made nozzle, tappet plate and cylinder head.
They are pretty awesome actually. They have a 6 mm tappet plate connected to a 8 mm nozzle connected to a cylinder head which is about 2 mm longer and a slightly shorter cylinder.
It’s a pitty Chainsaw don’t sell some of these parts individually.
Here is a pic showing the original APS gear and the other showing the custom parts which come inside a MPX.