Decided to stripp the MS 650 chainsaw.

[alsayyed]

Hello friends, today I have decide to dismantle the Stihl MS 650 chainsaw parts by parts like I did to MS 660 before. Buy my mistake is when it comes to assemble it again I get confused in placing the screws in the proper hole. I cannot believe how dirty from inside, too much saw dust.
The only problem maybe I will face with difficulty in removing the crankshaft. Dose anybody have tried to strip the a chainsaw before and what is the thing you have to put in mind during the operation.

[Rocky_J]

Not bad. It only took you a year and a half to kill that poor saw.  8)

[Al_Smith]

 I don't think a year and a half is a record but a darned good average  ;D.All chainsaws reassemble exactly opposite of the way they diassemble .The last bolt taken out is the first one put back on .

Once you get to the last bolt of reassembley which is also the first bolt of disassembley ,it's as good as new .--Trust me .

[SawTroll]

..... 

The only problem maybe I will face with difficulty in removing the crankshaft. Dose anybody have tried to strip the a chainsaw before and what is the thing you have to put in mind during the operation.

Why do you want do that - can't be much sawdust down in the crankcase.... ???

[joe_indi]

Hello friends, today I have decide to dismantle the Stihl MS 650 chainsaw parts by parts like I did to MS 660 before.

So, what happened to your MS660?
Have you been able to put it back together or is it still in pieces?
If you did put it back together again I dont see you having any problem with your MS650. They are both the same except for the piston & cylinder.
But if your 660 is still in pieces, do you really need to be attempting  the same again?

Not bad. It only took you a year and a half to kill that poor saw.)

I second that

[alsayyed]

Thank you guys for following this. I have did stripped it very well removed almost everything. I cleaned it very well and very clean, unbelievable how much dust stuck under and inside the machine. I cleaned the oil pump and libricated few other parts. Checked the hoses all are good opened the carb and cleaned it very well.  Regarding MS 660 I have assembled this machine long time and used it very well..
Know I have faced with another  small problem. I tried to started but is not going very well. I took few drops of fuel and pour into the spark plug hole and I have pulled the rope and started and stopped , I have checked impulse hose is good and checked few other things are good. The piston is super nice. I think no gas is going the carb, or the carb is not sucking  gas, I have looked at the carb and it was very well, know since I am almost done and ready  tomorrow to go for wood milling.

[joe_indi]

If no gas is going into the carb, you need not strip the whole saw.

The most common reasons are: blocked pickup body, leaking fuel hose, leaking impulse hose, leaks in the carb gaskets, blocked strainer in the carb, stuck metering needle.

Not so common reasons:Blown cylinder gasket, loose or missing cylinder screws, blown oil seals.

But, in your case, going by the description of the quantity of saw dust in the crankcase, I strongly feel the cause is elsewhere.
I see this happening here too especially when the air filter mesh is damaged or a blunt saw chain is used.Saw dust gets sucked into the engine and a certain quantity of it along with  gum are pushed through the impulse hose to the bottom carb cover.
This causes two things.The packed saw dust restricts the movement of the pump diaphragm.The gum buildup eventually blocks out the air impulses that work the pump.
Another carb component that gets damaged by the flow of saw dust through the carb is the jet valve.This is a sort of non-return valve.Saw dust intrusion into this valve causes it to lose its function.The result? Air enters the metering chamber and prevents the metering diaphragm from activating the metering needle.End result? No fuel in the carb.

Joe

[alsayyed]

Hello Joe and hello to the rest of the friends I thank you very much for taking your time explaining to me in details about the carb. The reason I have stripped the machine after 5 years in milling wood decided to do full maintenance like changing the crankshaft bearings, and lubricating some parts, tighting some screws, do not be surprise if I tell that I have found out that the  piston cylinder 4 screws are little loose.  Other reason is to get familiar with the saw  in case something happened to it.

I will go through the carb again to check the needle.

I appreciate your answer thank you again.

[joe_indi]

If your location is Qatar.maybe some time you could take a 3-4 hour air trip to my place and I could show you all I can about chainsaws.
Think about it
Joe

[Al_Smith]

 Well perhaps I should not bring this up being the Internet as it is .How some ever it totally amazes me at some of the questions that get brought up on this forum .


You know at times I almost think some people are kind of like testing the rest of our intelligence in working with saws kind of thing .

Perhaps I'm wrong in my thinking but it surely makes a person wonder . ???