Jump to content

Log in or register to remove this advert

What's on your bench today?


spudulike

Recommended Posts

Log in or register to remove this advert

Busy day today. Some tree work morning.

 

Then two Kawasaki strimmers. One was. Running fine after a fettle with the meter valve.

 

The other is strange, it will run fine one minute but then it won't start. Hot, cold, just takes forever. Will die on tickover sometimes but will always rev and stay high. Just tickover. Swapped the carb for the other one and same things.

 

Checked the gaskets, spacers and metering valve. All seem ok. The return to the tank seems old and a bit lose. Could this be it? But I did change it with the other carb. They both seem to run fine when I finished. Will see when testing them out properly.

 

The other was an ms280. This saw has been a thorn.

 

It was running a bit rough when it was used. Bit now its worse. It won't start without choke and will not tickover. Have to hold full throttle to get it to start. Will die if let to go tickover. But can be regained if throttle pulled. Much the same symptoms as the 200t and crank seals. Will need to test it later.

 

So a question for all the techies. What does everyone know about metering valves and there settings, I know some carbs have a ridge that they get set to but others don't, so the question is.

 

Is there a general setting without the use of testers?

Link to comment
Share on other sites

OK, first the Kawasaki that dies on tickover. Classic example of poor compression, or an inlet air leak somewhere between the carb and the pot. Any such leak can be dissproportionaly large at low revs. In other words can be tuned out on the H screw but not at low speed on the idle jet.

 

The 280 could be similar. I would check this before going further.

 

With regards to the height settings, they do vary from carb to carb, although most we encounter will be the zama c1q or walbro wt.

 

Rather than try for general guidelines just get the zamx'Z' guage and the walbro 'W'. They are cheap and worth their weight in gold. Let me know if you have any trouble sorcing them.

Link to comment
Share on other sites

I see what your saying about the screws. Except the carbs don't have the h and l screws. Not that I can see anyway.

 

They are a strange one. They are running perfectly now. Will find out in a few days.

 

The 280 has auto tune on the h screw. Will see when I'm testing it. I've seen the w and z testers on ebay once but not sure if they are still available. Will have a look. One thing I havnt got yet.

Link to comment
Share on other sites

I see what your saying about the screws. Except the carbs don't have the h and l screws. Not that I can see anyway.

 

They are a strange one. They are running perfectly now. Will find out in a few days.

 

The 280 has auto tune on the h screw. Will see when I'm testing it. I've seen the w and z testers on ebay once but not sure if they are still available. Will have a look. One thing I havnt got yet.

 

Second on the W and Z gauges - cheap and do the job. Most of the time I just use a steel rule to get the 0 - 0.3mm below the carb body on the majority of carbs and the W one is good for the lower set metering arms!

Link to comment
Share on other sites

Got the latest MS200T on the bench, the piston has a bit of a score down its skirt but the rest of the piston is in good condition, machining marks still in place, the rings are 100% and compression is 160psi.

 

The bore is OK, a slight mark above the exhaust port and slight score below it in the non compression effecting position. I have given it a bit of a smooth over as in the pictutre - reckon the piston will be OK as well unless the owner wants a new one. I think a little rub with emery and all will be good.

Piston.jpg.13280aa241a21d3c47f6a6d1ae084b43.jpg

Bore.jpg.973502852a59e7b35302bde5b9281898.jpg

Link to comment
Share on other sites

Of course, Rich. You will have the rotery barrel type Walbro carb. WY or WYL.

 

Some ( very few) do have a high jet adjuster, but most only have an idle adjuster which can be difficult to spot initially. Some are ajustable by prising out a tiny plastic plug in the centre of the plastic barrel. Adjust with a jewellers screwdriver.

 

Others dont have the plug, but are sealed with a plastic core pushed deep into the hole.

Screw a small, sharp, self tapper about 2 mm into this plug and pull it out with some pliers, this will expose the adjuster screw as in the first example. ( I have a ST screw weled to an old screwdriver for removing the core)

 

Some are sealed and not adjustable.

 

Adjustment of this alone may well cure your problem.

 

And, yes the Z & W guages are still readily available.

Link to comment
Share on other sites

Of course, Rich. You will have the rotery barrel type Walbro carb. WY or WYL.

 

Some ( very few) do have a high jet adjuster, but most only have an idle adjuster which can be difficult to spot initially. Some are ajustable by prising out a tiny plastic plug in the centre of the plastic barrel. Adjust with a jewellers screwdriver.

 

Others dont have the plug, but are sealed with a plastic core pushed deep into the hole.

Screw a small, sharp, self tapper about 2 mm into this plug and pull it out with some pliers, this will expose the adjuster screw as in the first example. ( I have a ST screw weled to an old screwdriver for removing the core)

 

Some are sealed and not adjustable.

 

Adjustment of this alone may well cure your problem.

 

And, yes the Z & W guages are still readily available.

 

Thanks. Again an age of experience and information available.:thumbup:

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  •  

  • Featured Adverts

About

Arbtalk.co.uk is a hub for the arboriculture industry in the UK.  
If you're just starting out and you need business, equipment, tech or training support you're in the right place.  If you've done it, made it, got a van load of oily t-shirts and have decided to give something back by sharing your knowledge or wisdom,  then you're welcome too.
If you would like to contribute to making this industry more effective and safe then welcome.
Just like a living tree, it'll always be a work in progress.
Please have a look around, sign up, share and contribute the best you have.

See you inside.

The Arbtalk Team

Follow us

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.