Blocked main jet 200t

[Maxnaggle]

Hey all, currently on a mission to get my 200t to run properly.... Swapped the zama carb with the accelerator pump for one without, and it only responds to the low speed adjustment (left screw)

 

turning the high speed screw does nothing to change the way the saw runs.

 

Strangely enough it does run and rev on the low speed jet.. Just not very well..

 

Does anyone know how I can access the jets and clean them?

Thanks!

[Maxnaggle]

Okay so I've taken the carb off, taken the diaphragm off and any other rubber/plastic components, removed the high and low adjustment screw's and put what was left in boiling water, to hopefully clear the main jet.

Only did it this way because I couldn't find any carb cleaner :c

Had a little poke about with a needle as well,

When everyone else in the house wakes up I'll see if it did the trick haha

[spudulike]

Okay so I've taken the carb off, taken the diaphragm off and any other rubber/plastic components, removed the high and low adjustment screw's and put what was left in boiling water, to hopefully clear the main jet.

Only did it this way because I couldn't find any carb cleaner :c

Had a little poke about with a needle as well,

When everyone else in the house wakes up I'll see if it did the trick haha

 

I don't know where you stuck the needle but your "main jet" is in fact a one way check valve that acts like a jet but only lets fuel flow one way. It IS possible that jet has stuck and removing the H screw and gettinng some carb cleaner or WD40 down it will tell you if it is blocked - expect to see a spray of fuel entering the bore of the carb when looking down it.

 

The symptoms you have are also the same for a big air leak, a small seize, a semi blocked gauze filter, holed fuel line etc!

[Maxnaggle]

Hi spud,

Just put it all back together and its the same, the saw runs o.k but messing with the high screw has no effect on the way it runs. It revs out okay and can be used for cutting, but I'm pretty sure it could be running a lot better - it isn't lumpy, it just doesn't rev as high as I think it should..

The saw isn't really erratic when it does run, and the plug looks good, I don't think there is an air leak, I've had the boot off a few times and it seemed in good condition.

I'm currently bypassing the accelerator pump on the old carb and will have a go with that one as well.

The fuel line looks good, I'll have a look at the air filter though.

Thanks!

[Maxnaggle]

Okay so put the original carb back on and it ran worse than ever! Woohoo!,

So I took that one of and put the freshly cleaned one back on, took out the little foam bit that lives in behind the air filter, which I noticed was quite oily.. So I've left it out for now.

Got the saw nice and hot and its about one turn out for the low and one for the high.

It responds to the high screw being tweaked now, maybe I was being impatient this morning..

Time will tell! Going to let it cool right down and have another go.

[spudulike]

Okay so put the original carb back on and it ran worse than ever! Woohoo!,

So I took that one of and put the freshly cleaned one back on, took out the little foam bit that lives in behind the air filter, which I noticed was quite oily.. So I've left it out for now.

Got the saw nice and hot and its about one turn out for the low and one for the high.

It responds to the high screw being tweaked now, maybe I was being impatient this morning..

Time will tell! Going to let it cool right down and have another go.

 

I have known these carbs to take a while to settle. It will probably be OK now. The gauze filters can sometimes look fine but have a dried scum in the open holes - worth taking it out and giving a close look if it persists.

[Maxnaggle]

Hi spud, so far so good! Used it in some fairly thick thuja today and I think it's nearly there. Just bogs ever so slightly on pick up unless I feather the throttle, maybe to much fuel? Thanks

[spudulike]

Hi spud, so far so good! Used it in some fairly thick thuja today and I think it's nearly there. Just bogs ever so slightly on pick up unless I feather the throttle, maybe to much fuel? Thanks

 

Probably a little lean on the L screw!

[Maxnaggle]

Hello again! The problem persists... I can not get this saw to run properly (so far)

So far it has had

New carb

Pot and piston (for what it's worth)

Fuel line & breather

Impulse line

Carb boot

The issue I have is that it will not tick over with the carb set up properly (1 turn out on the h&l screw)

 

If i have the l screw really lean, at about a quarter of a turn out it will then tick over for a period of time, but is quite racey and eventually cuts out. Plus under load it usually bogs down. Bit of a pig to work with!

 

The idle screw seems to make no difference at all in both instances...

 

Someone help!! Haha

[Stubby]

Time to send it to Steve me thinks .......