advice for a noobie chainsaw user

[Eddy_t]

Maybe. But it does mean he's forgotten more about how to use and repair a chainsaw than any of us ever knew. Unlike my first response, this one isn't a joke. The guy knows his stuff, and he's not messing around.

 

Never said he didn't, the bloke definitely knows his stuff, but you can still develop bad habits

 

 

Sent using Arbtalk Mobile App

[chrismechanic]

For all we know, that may be what he's trying to prevent with the pull cord.

 

yes, your right there, some old 2 strokes with points used to kick back and run backwards breaking the pull starter chord... a mate had a honda trial bike years ago.. it would run backwards too, real funny the first time it happened as my mate was trying to pull a wheelie, he ended up with a fuel tank in the balls

chris

[wyk]

... you can still develop bad habits

 

 

Sent using Arbtalk Mobile App

 

I think he smokes.

[Eddy_t]

I think he smokes.

 

So do I, and we both collect and repair chainsaws...

 

 

Sent using Arbtalk Mobile App

[Chris Sheppard]

yes, i would say it's a bit of ring or spark plug has made those marks.

the damage could be removed on the mill using the rotary table to spin the head around, just on that flat face inside the combustion chamber.

 

that would lower the compression ratio too by a small amount, but tbh you dont want to lower it by much or you'll end up with a poorly running bike .

 

so when you say angle are we talking the dished part that leads up to the spark plug hole, apart from that part of the head the rest looks flat from the pic.

 

you could have a shim made to fit inbetween the cylinder and the head, that would also work and if it lowered the compression too much could easily be removed.

 

here is a very small 2 stroke head i did some external work on... the guy just wanted the outside cleaning up after crash damage

 

before..

[ATTACH]139923[/ATTACH]

 

and after

[ATTACH]139924[/ATTACH]

 

chris

 

Cheers,

 

Problem with spacers is that it uses O rings instead of gaskets so would need to be quite thick to accomodate a second set of O rings.

 

I'm ideally looking to lower the compression the equivalent to adding a second base gasket, lose the worst of the damage and keep the squish the same. It's the squish bit I get lost on

 

It's bad to see from the photo but the damaged bit is angled a bit. Between the flat surface that meets the top of the cylinder, and the domed bit.

Edited November 9, 2013 by Chris Sheppard

[chrismechanic]

so that is the angled part you are concerned about.. that will be ok flat, but if you are worried i can repeat the angle on the lathe, it is not a problem at all.

what is the diameter of the head?

chris

[pycoed]

Eddy,

Just seen this thread & your problems with D2 steel bar. I've read that many American gunsmiths, when making sporters out of military rifles, often have to work on seriously hardened Mauser actions. A trick they use is to mark carefully the position the hole is needed & then run a plain piece of what they call "drill rod" ("silver steel" in UK) in the milling machine chuck at high speed. This is used to "drill" the hardened steel until it runs to full red heat, but before welding occurs! The result is a localised softer spot in the hardening which can then be drilled in the normal fashion. May be worth a try, since it's very easy to do?

[Eddy_t]

Tbf it's not what I've gotta do, as I said, I've given it to an engineer to sort out, I had a go, I gave it him, it's his job to sort it, I had always thought chainsaw guide bars were hardened mild steel or a bit better (certainly Oregon/husqvarna bars are made of mild steel, if not pure iron!).

 

 

Sent using Arbtalk Mobile App

[chrismechanic]

hi guys, more advice please.

 

i am now using my saw every 2-3 days to chop up fire wood to keep the workshop warm.

 

remember my post about the fuel tank pickup? the saw was stalling so i figured it was running out of fuel at low tank level due to the pick up sticking up above the fuel, the pickup is now staying in the corner of the tank laying down and the saw is still stalling.

 

the other day i used nearly a whole tank cutting timber, i noticed that everytime i left the saw on the floor on idle (even when the tank was full) as soon as i picked up the saw it would cut out.

i also noticed that after some cuts it would run on for a few seconds then go back to idle speed.

 

as i said before im a 4 stroke engine mechanic but i have lots of experience with 2 stroke nitro engines (rc model car glow engines).

now if a glow engine is running too lean it will run on for a few seconds before returning to idle, so im guessing my saw is running lean.

 

the saw has about 3 lt of fuel through it now and i have cleaned the air filter out twice.

 

what do you think guys... does it sound like it is lean by the run on?

also i have turned up the tickover screw by half a turn, the chain didnt run so i thought it was about ideal, what about the stalling?

thanks,

chris.

[Eddy_t]

Breather possibly, that would cause it to lean out too, is it a bugger to get the fuel cap open when it's run empty?

Otherwise it could be an air leak

 

 

Sent using Arbtalk Mobile App