Adding A Decompression Valve To A 288 Husqvarna

[rickyrooster]

I've got a 288 Husqvarna parts saw that I'm going to rebuild. The cylinder that came with it is in good condition and has the boss cast into the side for a compression release button but has not been machined for it. Has anyone done this. I would assume breaking thru plating on the id of the cylinder would be the trickiest part. Does anyone know what size tap is needed to thread the hole. Any tips would be a big help. Thanks Rick!

 

[brncreeper]

Not sure what size drill and tap you're going to need, but with aluminum I like to go one size smaller on the drill size.

Today I missed the decompression on the 084, talk about unforgiving...OUCH!:censored:

 

[SawTroll]

It sure is possible, but I don't know the details - someone here sure will......


Cuttinscott do it routinely on the 5100, I believe......

 

[carvinmark]

Today I missed the decompression on the 084, talk about unforgiving...OUCH!:censored:

Done that, double ouch!

 

[sugarbush]

I've got a 288 Husqvarna parts saw that I'm going to rebuild. The cylinder that came with it is in good condition and has the boss cast into the side for a compression release button but has not been machined for it. Has anyone done this. I would assume breaking thru plating on the id of the cylinder would be the trickiest part. Does anyone know what size tap is needed to thread the hole. Any tips would be a big help. Thanks Rick!

make a jig, I made mine out of plywood, 2 sides w/ ends capped. drill holes in box to bolt cyl.-- if you try and free hand it you may snap the small bit.

1/8 bit
11/32 bit, use a bit stop or tape to make sure you don't go to deep. allow for decomp to open up.
10mm- 1.o tap

 

[dugide]

It sure is possible, but I don't know the details - someone here sure will......


Cuttinscott do it routinely on the 5100, I believe......

I think he was sending his out to a machine shop.

 

[stihl 440]

288xp

Why would you need a decomp on a 288? I have a 288 up at work that I use...I start it no problem.....of course I don't use the decomp on any of my saws any more....lol:greenchainsaw:

 

[Trigger-Time]

I just bought an NOS 288XP PC kit W/O the decomp.

 

[rickyrooster]

I'm going to do this myself. I have bridgeport mill to do it on. I was wandering if anyone had done it in the past and if there were any problems to watch out for. I know that a lot of those who race do not want the compression releases on there saws but I would like to build a good work saw (mild woods ported) to use for my larger firewood needs. To tell the truth I dont really have a need for a 288 my 72cc jonsered does 99.9% of anything I want it to in the fire wood pile. I just want a bigger saw for the sake of saying ive got one. So there I said it, I'm addicted to this crap and bigger is always better right? I like the ease of starting by having the release vavle on it and am going to figure out how to get it. thanks Rick!

 

[Nailgunner]

I'd think you'll need a very nice smooth finish on the inside, and very likely you'll want to support the inside of the cylinder to make sure the lining isn't pushed in by the cutter. High speed carbide cutter, slow feed and avoid snatching on breakthrough. De-burr carefuly and enjoy your easy-to-start monster-size chainsaw.

I'd quite like an 80cc+ saw. hmm.

 

[rickyrooster]

Well I took the cylinder into work today and have got it done. I used a 3/4 in end mill and spot faced the boss so it would have a machined surface for the seal on the relief valve to seat against. drilled a 3/32 hole thru the center of the boss into the cylinder then followed with the letter S drill .500 deep. hand tapped the 10-1.0 mm hole and then used a 1/8 in ball diamond burr in the electric die grinder to bevel the 3/32 hole in the id of the cylinder. every thing came out great and you cant tell it did'nt come from the factory this way. thanks for everyone help and input. sorry I didnt take any pictures but I didnt want to draw attention to what I was doing in front of the boss LOL. Rick!