What's on your bench today?

[wisecobandit]

Is garden kit in tonight?

Remember i asked you about my hayter 12/30, well deck is prepped with black waxoil, new blade and going to check blade levelness.

Well i adjusted the throttle cable as we said about the other day, choke works fine now but it seems a bit hesitant when throttle opened. Presumably i need to adjust a screw on carb? Any idea which one as it doesnt really say on the nanual i downloaded.

Many thanks

May pay to put the above up on the mower thread

Barry (gardenkit) is pretty busy at work at the mo including working some sundays but tends to keep an eye on that thread when he gets chance. It may get eaten up here and he may miss it if it ends up a few pages back by the time he gets chance to visit

[GardenKit]

Its OK guys, I just checked in!

 

Agi, it is fairly common to experience the flat spot that you mention. It may well be due to blocked transitional jets in the idle circuit. Carbs generally have 2 fuel circuits:-

 

When the throttle butterfly is open there is a high pressure area before the venturi, this pressure pushes down on the fuel and forces it up through the main jet into the ventori. It gets mixed with air on the way to form a vapour. On modern carbs it is not usual to have any adjustment on this jet.

 

But when the butterfly is closed to slow the engine down the pressure drops shutting off the fuel. Now another circuit called the idle circuit comes into play. The low pressure area at the tip of the butterfly has a small drilling allowing a small amount of fuel to be pulled out to allow idle. This circuit did have a mixture screw until very recent changes to carbs, so yours will have it. There are also a couple of transitional drillings on the idle circuit before the mixture screw which allow a little fuel through to ease the transition between the idle jet operating and the main jet taking over. These may be blocked on you carb and a deep clean could be needed.

 

But, it may help to tune the idle ciruit first. The screw will be found just above the bowl flange on the left of the carb as you view it from the nearside front wheel area. The screw may originally have had a plastic limiter cap. if its still there it may be best to remove it.

You will then see a slotted head screw, or just a splined screw head with a spring beneath. The splines were to hold the plastic limiter, you can turn the screw with grips.

 

With the air filter clean, fresh fuel and a clean plug, you can run the engine at tickover. Adjust the tickover speed using the cross headed screw just above and slightly right of the mixture screw. Try to get a nice even tickover, not too fast and not too slow.

 

Then adjust the mixture screw, very slowly. Firstly screw it in. If the engine speed picks up then keep turning until the revs start to drop (lean drop off point)

Then turn it out until the revs rise, and then start to drop off and get lumpy (rich drop off point)

Remember the amount you have turned the screw between both points, then turn the screw in until the revs start to rise and even out nicely. (slightly rich rather than slightly lean)

Adjust the slow speed idle screw (the cross headed one) to get a nice idle speed. You dont want it too fast but the higher it is, the less you will notice the 'flat spot' effect.

 

If the mixture screw makes no difference at all then the idle circuit is blocked and will need cleaning. You may be able to do this by removing the screw and squirting some carb cleaner in, but more than likely it will need an ultrasonic clean.

 

Hope this helps.

Barrie

[wisecobandit]

Its OK guys, I just checked in!

 

Agi, it is fairly common to experience the flat spot that you mention. It may well be due to blocked transitional jets in the idle circuit. Carbs generally have 2 fuel circuits:-

 

When the throttle butterfly is open there is a high pressure area before the venturi, this pressure pushes down on the fuel and forces it up through the main jet into the ventori. It gets mixed with air on the way to form a vapour. On modern carbs it is not usual to have any adjustment on this jet.

 

But when the butterfly is closed to slow the engine down the pressure drops shutting off the fuel. Now another circuit called the idle circuit comes into play. The low pressure area at the tip of the butterfly has a small drilling allowing a small amount of fuel to be pulled out to allow idle. This circuit did have a mixture screw until very recent changes to carbs, so yours will have it. There are also a couple of transitional drillings on the idle circuit before the mixture screw which allow a little fuel through to ease the transition between the idle jet operating and the main jet taking over. These may be blocked on you carb and a deep clean could be needed.

 

But, it may help to tune the idle ciruit first. The screw will be found just above the bowl flange on the left of the carb as you view it from the nearside front wheel area. The screw may originally have had a plastic limiter cap. if its still there it may be best to remove it.

You will then see a slotted head screw, or just a splined screw head with a spring beneath. The splines were to hold the plastic limiter, you can turn the screw with grips.

 

With the air filter clean, fresh fuel and a clean plug, you can run the engine at tickover. Adjust the tickover speed using the cross headed screw just above and slightly right of the mixture screw. Try to get a nice even tickover, not too fast and not too slow.

 

Then adjust the mixture screw, very slowly. Firstly screw it in. If the engine speed picks up then keep turning until the revs start to drop (lean drop off point)

Then turn it out until the revs rise, and then start to drop off and get lumpy (rich drop off point)

Remember the amount you have turned the screw between both points, then turn the screw in until the revs start to rise and even out nicely. (slightly rich rather than slightly lean)

Adjust the slow speed idle screw (the cross headed one) to get a nice idle speed. You dont want it too fast but the higher it is, the less you will notice the 'flat spot' effect.

 

If the mixture screw makes no difference at all then the idle circuit is blocked and will need cleaning. You may be able to do this by removing the screw and squirting some carb cleaner in, but more than likely it will need an ultrasonic clean.

 

Hope this helps.

Barrie

The manufactuers really need to take you on to write there workshop manuals :thumbup:

There problem solving answer would just be "carb fault, replace carb"

[div_h]

Evening..... I spilt the crankcase on my 026 today👍 How do I remove the crank bearings with out knackering anything else on the crank its self or the side casing

[spudulike]

Evening..... I spilt the crankcase on my 026 today👍 How do I remove the crank bearings with out knackering anything else on the crank its self or the side casing

 

On the case without the crank sticking out of it -put a suitable socket on the outer side of the bearing and use a bench vice to push on it to ease it out - PROTECT THE GASKET EDGE and don't assume the casting is mega strong!

 

The crank can be pushed out with a large 10" or more G clamp and a U shaped fabricated attachement so the clamp pushes on the crank end so it can slide out. You may be able to use a bench vice for this part rather than the G clamp - it works on smaller saws.

 

Once the crank is out, use the same method to remove the other bearing.

 

The new bearings can be put in in the same manner but make sure the surfaces are clean.

 

If the bearings are OK, I would leave them as is and save the money:thumbup:

[Adamam]

Evening..... I spilt the crankcase on my 026 today👍 How do I remove the crank bearings with out knackering anything else on the crank its self or the side casing

 

There is a series of brilliant videos on YouTube by andy reynolds about 026 bearings. He is a proper YouTube hero!

 

Defo covers everything you need.

[div_h]

On the case without the crank sticking out of it -put a suitable socket on the outer side of the bearing and use a bench vice to push on it to ease it out - PROTECT THE GASKET EDGE and don't assume the casting is mega strong!

 

The crank can be pushed out with a large 10" or more G clamp and a U shaped fabricated attachement so the clamp pushes on the crank end so it can slide out. You may be able to use a bench vice for this part rather than the G clamp - it works on smaller saws.

 

Once the crank is out, use the same method to remove the other bearing.

 

The new bearings can be put in in the same manner but make sure the surfaces are clean

 

If the bearings are OK, I would leave them as is and save the money:thumbup:

 

Thanks Steve

 

I have the crank right out already some blocks of wood and a copper hammer the bearings are a tad rough... I'm scared of braking something removing the bearings or pressing them in! Trial and error

 

I was looking forward to making crankcase splitter today but I gave the clutch side of the crank a clout with my copper whacker and it split no bother

 

I want to change all the bearings seals and piston.. Plus I needs the parts that are missing

[div_h]

There is a series of brilliant videos on YouTube by andy reynolds about 026 bearings. He is a proper YouTube hero!

 

Defo covers everything you need.

 

Thanks bud I will check them out

[wisecobandit]

Just tap the old bearings out using an appropriate socket and hammer on the 026. Make sure you tap the socket square on with a hammer and they will pop out without to many issues. Once they start to move they will literally fall out.rankcas

The stihl crankcases are usually easy to split and when you put them back together a few taps and pulling them up evenly on all the bolts will see it close up easy enough.

 

When you do a Husqvarna that's when you want heat and a crankcase splitting tool.

Edited March 18, 2015 by wisecobandit

[div_h]

Just tap the old bearings out using an appropriate socket and hammer on the 026. Make sure you tap the socket square on with a hammer and they will pop out without to many issues. Once they start to move they will literally fall out.rankcas

The stihl crankcases are usually easy to split and when you put them back together a few taps and pulling them up evenly on all the bolts will see it close up easy enough.

 

When you do a Husqvarna that's when you want heat and a crankcase splitting tool.

 

1 of the bearings is still on the crank just don't want to make a mess of it