ms200t Idle issues

[sloch24]

Well, I got the ms200t put back together with new rings. Fuel line and impulse line looked okay, so I didn't change them. The crank bearings felt tight.

I took the saw outside and started it up, it immediately wanted to die when I hit the throttle, so, I took the carb off of my sacrificial saw and tried it (it was the older type carb). The saw took off and ran great, plenty of throttle response.

It seemed to idle okay, so I adjusted the H screw until it was just barely burbling at WOT. I haven't tached it yet, but I figure if it's burbling, it's fine.

Here's the problem. The saw has idling issues. I didn't take the carb apart to clean or rebuild yet, and I'm wondering if I have a carb issue, or an air leak. One thing I didn't do was replace the cylinder gasket. Is that a no-no on this saw? The gasket looked fine, so I just put the cylinder on the saw. Now that I think about it, the cylinder might be from the other saw as well... I did take the piston out of that saw, it looked very good. No mill marks, but no scoring what so ever.

I can mess with the L screw and idle screw and it seems like it's okay, but then I set the saw down, pick it up and start turning it in different positions, it seems like it speeds up a little, then dies shortly thereafter. After it stalls, it seems to be starved for gas. I pull the rope and hit the trigger, and it will start right up.

I've put kits in carbs in the past, but I didn't want to waste the money if it sounds like an air leak.

If it IS an air leak, I'm tempted to buy a pressure/vac kit off of ebay.. (it would be nice to have anyway).

Waddaya all think?

 

[sILlogger]

Well, I got the ms200t put back together with new rings. Fuel line and impulse line looked okay, so I didn't change them. The crank bearings felt tight.

I took the saw outside and started it up, it immediately wanted to die when I hit the throttle, so, I took the carb off of my sacrificial saw and tried it (it was the older type carb). The saw took off and ran great, plenty of throttle response.

It seemed to idle okay, so I adjusted the H screw until it was just barely burbling at WOT. I haven't tached it yet, but I figure if it's burbling, it's fine.

Here's the problem. The saw has idling issues. I didn't take the carb apart to clean or rebuild yet, and I'm wondering if I have a carb issue, or an air leak. One thing I didn't do was replace the cylinder gasket. Is that a no-no on this saw? The gasket looked fine, so I just put the cylinder on the saw. Now that I think about it, the cylinder might be from the other saw as well... I did take the piston out of that saw, it looked very good. No mill marks, but no scoring what so ever.

I can mess with the L screw and idle screw and it seems like it's okay, but then I set the saw down, pick it up and start turning it in different positions, it seems like it speeds up a little, then dies shortly thereafter. After it stalls, it seems to be starved for gas. I pull the rope and hit the trigger, and it will start right up.

I've put kits in carbs in the past, but I didn't want to waste the money if it sounds like an air leak.

If it IS an air leak, I'm tempted to buy a pressure/vac kit off of ebay.. (it would be nice to have anyway).

Waddaya all think?

my guess is that it needs crank seals.. but somebody more knowledgeable will be along t let you know for sure

 

[sloch24]

my guess is that it needs crank seals.. but somebody more knowledgeable will be along t let you know for sure

I wondered about that, but with the bearings so tight, I *assumed* that they were probably okay.

 

[Paul001]

I wondered about that, but with the bearings so tight, I *assumed* that they were probably okay.

The only way you can tell is to Pressure/Vac test it. Do you have the single pick up comming out of your fuel tank or double?

Either way, make sure to pressure test your fuel line.

Were there any broken AV mounts?

Pah, before you go any further, do a search here for the DIY pressure/vac tester. Cost was something like $25 to build. On this particular saw and with the issue you are having, other than replace with known good part(Chilton sytle) there isn't any other good way to sort this out.

Also, get the model numbers off both of your carbs. That info would be helpful.

 

[sloch24]

This tank has the single point coming out of the tank with the fuel line and vent. I looked over the fuel line where it comes out of the tank, and it's still in very good pliable condition. I didn't, however, inspect what was inside of the tank. hmm....

I believe the carb that's on it now is a "C1QS32". It doesn't have a limiter cap on either jets, and the H + L screws are RIGHT next to each other... I found out that I have to take off the grommet to adjust the low... The saw originally had a "C1QS61" carb on it.

 

[funky sawman]

I've seen a bunch of carb problems with those saws so now I just put a new carb on them and they always leave the shop happy.

 

[sloch24]

I've seen a bunch of carb problems with those saws so now I just put a new carb on them and they always leave the shop happy.

If I had a *known* good carb, I'd give it a try... Although, I should just buy one because I know the one on the other saw is bad...

 

[Lakeside53]

The S32 is a butt-simple carb.. none of the problems of the S61. Just rebuild it if you're concerned.

Squirt some carb cleaner at your base gasket. If it changes idle, then it's leaking. You shouldn't reuse gaskets, but if you do put on a thin smear of gasket sealer.

Seal failure is rare on the 200t... and as you'll notice, they are not "ordinary" seals - they have a skirt instead of a lip, and must be installed the correct way around.

How was the piston skirt wear? No mill marks means worn... and a worn skirt will give idle instability on the 200T.