What's on your bench today?

[spudulike]

An older ms200t being a pain in the arse..... i said on here a month or so ago it was playing up.... re adjusted carb and was ok... started playing up yet again today..... sat at idle then high reving like an air leak etc....

 

also has it ever been known to happen that the carb screws turn themselves?

 

anyhow cant be arsed with it now! its my hedge saw.... pita!

 

Not seen moving carb screws before, the issue may be an air leak so do the vac and then the pressure check, you could try moving the handle and imulse about with the saw on the deck and see if the revs change as if the problem is with these components, doing this will change the revs.

 

You could try swaping carbs with a good carb and see if the problem goes away.

 

I have had similar issues and it is possibly a leaking welch plug or the accelerator pump if the vac and pressure tests come up fine.

[spudulike]

The pot and piston for the makita that I have found is, about 50 quid. That's a bit more than the stihl ts pot and piston.

 

I guess you are talking aftermarket parts here Rich or have you left a zero off for Stihl parts:001_rolleyes:

 

You would be lucky to get a Stihl piston for 50 notes:lol:

[Rich2484]

I guess you are talking aftermarket parts here Rich or have you left a zero off for Stihl parts:001_rolleyes:

 

You would be lucky to get a Stihl piston for 50 notes:lol:

 

Yah forgot that bit about aftermarket, price was on a meteor piston and aftermarket pot. But not the cheap Chinese plonk.

[Daniël Bos]

Yah forgot that bit about aftermarket, price was on a meteor piston and aftermarket pot. But not the cheap Chinese plonk.

 

I'm interested now, what "not cheap chinese plonk" cylinder can you buy for £50 minus the cost of a meteor Piston?

[Rich2484]

I'm interested now, what "not cheap chinese plonk" cylinder can you buy for £50 minus the cost of a meteor Piston?

 

Whoops. Sorry. :lol:

 

Guess on how much you have to pay for the meteor piston doesn't it. wink wink.....

[swinny]

Not seen moving carb screws before, the issue may be an air leak so do the vac and then the pressure check, you could try moving the handle and imulse about with the saw on the deck and see if the revs change as if the problem is with these components, doing this will change the revs.

 

You could try swaping carbs with a good carb and see if the problem goes away.

 

I have had similar issues and it is possibly a leaking welch plug or the accelerator pump if the vac and pressure tests come up fine.

 

Took apart. Cleaned everything. All looks fine. Comp test 150psi

 

Ran for a while reved ok... left running.... then reved full on and it struggled at top end a little reved but stuttered once or twice. Then went down to a fast idle when i let go...

 

Checked warm temp comp and it was 140psi...

 

Time for a piston and carb?

 

Zama carb on

 

Trying to see if its worth me bothering with or spares or repairs.

 

Cheers

[swinny]

Dont have pressure vac stuff

 

This is a 3rd saw so dont want to spend much on it

[Rich2484]

Dont have pressure vac stuff

 

This is a 3rd saw so dont want to spend much on it

 

Pm sent bud.

[spudulike]

The ported 357XP is up and running, new clutch needle bearing, tank vent, clutch springs and rim drive. All sounds good, just needs a tach tune and a run through some wood.

 

The ported 254XP also lives, fitted two new crank seals and finally got it airtight after also sealling a very slightly leaking decomp valve thread.

 

The saw now has......a very interesting pickup, it was a little like an underground train before porting but now revs like a two stroke motorcross bike, need to get this tached and then a few cuts as well, early signs look good:thumbup:

[GardenKit]

The problems on most saws are normally simple, yet we get carried away into believing the worst.

 

I had a 200t today that was running poorly and changing its state of tune when put into work. Classic symptoms of a split inlet manifold. All you need to do to change the manifold is to undo the rear AV mount and remove the carb. The handle can be lifted sufficiently to remove the manifold. This one was split and so was replaced.

 

There is always a risk that the saw has had prolonged use with a split and has run weak resulting in the bore picking up and a subsequent loss of compression, so I always do a comp test, its quick and informative. This one was 150psi, so good to go.

 

It is also likely that the user has tried to tune out the problem before giving in and getting it repaired, so its best to check the carb screws. These were both 1 turn out, so good to go.

 

4 pulls got it going, it sounded quite good at revs, but died on releasing the throttle. The LA screw would not turn in any more. Strange, so fiddled the L screw, but to no avail.

 

I was now it bit baffled, there should not be more than one problem, so quickly popped on a known good carb. Perfect.

 

So stripped, cleaned and refurbished the original carb (an 020 type S16A carb), put it back on but still no tick over. Really baffled now, but turned my attention back to the idle speed LA screw.

 

This screw would go no further in, but rather than being in all the way, was in fact all the way out, but cross threaded. A clean up of the threads and it was moving freely again and I was able to adjust the tick over.

 

Sometimes it is easy to miss the obvious.