Saw dies a little, then accelerates

[mickdundee]

My stihl 038 AV Super dies off when I put throttle on then picks up to normal speed. The H & L screws are 1 turn out. The chain doesn't move on idle. It's on its first tank of aspen after always being ran on pump petrol. Any ideas please

[spudulike]

My stihl 038 AV Super dies off when I put throttle on then picks up to normal speed. The H & L screws are 1 turn out. The chain doesn't move on idle. It's on its first tank of aspen after always being ran on pump petrol. Any ideas please

 

Give the L screw 1/4 turn anti clockwise and increase the idle a little to compensate for the drop in revs. sounds like it is slightly lean in the low to mid range.

[mickdundee]

Ok thanks spud. I videoed it rather than try to explain it but can't figure out uploading it lol

[Stubby]

Also worth repacing the carb diafragm if you are going to stick with aspen . The pump fuel removes the coating ( to keep the rubber supple ) on the rubber components but the pump fuel itsef keeps it supple . Aspen will not remove this coating but if the run on pump fuel initially the rubber can harden . If running with Aspen from the get go not an issiue ...

[spudulike]

Also worth repacing the carb diafragm if you are going to stick with aspen . The pump fuel removes the coating ( to keep the rubber supple ) on the rubber components but the pump fuel itsef keeps it supple . Aspen will not remove this coating but if the run on pump fuel initially the rubber can harden . If running with Aspen from the get go not an issiue ...

 

Yes, you will find it will probably need a newcarb kit and fuel lines after a few tanks as you will start gettig fuel leaking around the fuel line where it pushes in to the tank.

[Eddie@aspen]

Yes, you will find it will probably need a newcarb kit and fuel lines after a few tanks as you will start gettig fuel leaking around the fuel line where it pushes in to the tank.

Hi all,

 

We have many Pro users who have switched to Aspen and NOT changed any parts.

 

I always recommend a Pro user changes these parts when switching just to be safe.

 

Up to you, now you know why they might need replacing.

 

Please phone 07568 108953 or email [email protected] if you need more help.

 

All the best and thanks for switching to Aspen!

[GardenKit]

Hi all,

 

We have many Pro users who have switched to Aspen and NOT changed any parts.

 

I always recommend a Pro user changes these parts when switching just to be safe.

 

Up to you, now you know why they might need replacing.

 

Please phone 07568 108953 or email [email protected] if you need more help.

 

All the best and thanks for switching to Aspen!

Totally agree with you there Eddie.

 

I have now changed many hundreds of machines to Aspen and most go without any problems. To be honest the diaphragms give very little trouble unless they were bad prior to the switch. Its the fuel lines that give the most problem but it does tend to be only some materials that suffer.

 

The 038 will have the old style black rubber pipe, and to be honest, this material is attacked by pump petrol and needs regular changing even if never running on Aspen.

But they can shrink, just as Spud says, when the petrol is removed. It is not the Aspen shrinking them, its just that they have been ruined by petrol.

 

The green synthetic hoses on some of the newer kit are perfectly OK, and in general machines with Tygon hose will not suffer either.

 

I have a high regard for Tanaka machines and have sold thousands over the years, but I know that I have to change the pipes and grommets when converting these from petrol to Aspen, or they will start to leak after a few weeks, but it only takes a few minutes and costs only a few pence to do.

But the same machines run on Aspen from new will never need new hoses.

[spudulike]

Totally agree with you there Eddie.

 

I have now changed many hundreds of machines to Aspen and most go without any problems. To be honest the diaphragms give very little trouble unless they were bad prior to the switch. Its the fuel lines that give the most problem but it does tend to be only some materials that suffer.

 

The 038 will have the old style black rubber pipe, and to be honest, this material is attacked by pump petrol and needs regular changing even if never running on Aspen.

But they can shrink, just as Spud says, when the petrol is removed. It is not the Aspen shrinking them, its just that they have been ruined by petrol.

 

The green synthetic hoses on some of the newer kit are perfectly OK, and in general machines with Tygon hose will not suffer either.

 

I have a high regard for Tanaka machines and have sold thousands over the years, but I know that I have to change the pipes and grommets when converting these from petrol to Aspen, or they will start to leak after a few weeks, but it only takes a few minutes and costs only a few pence to do.

But the same machines run on Aspen from new will never need new hoses.

 

 

I based my comments on a number od Stihls (MS211, MS200 etc) that have developed leaks around the fuel line entering the tank due to shrinkage when converted. Not a problem if you just change the part but don't like any fuel leaks especially on top handled saws due to the nature of the use of the saw.

[mickdundee]

That tweak has got it back to normal thanks spud. I'll keep an eye on the fuel lines etc for fuel leak and see how they get on.

 

Eddie, I should have always been on aspen really. Fuel sits in the shed too long and I notice it can be harder to start after a while. It's not going to cost me much extra a year and will hopefully be better for the saw in the long run

[spudulike]

That tweak has got it back to normal thanks spud. I'll keep an eye on the fuel lines etc for fuel leak and see how they get on.

 

Eddie, I should have always been on aspen really. Fuel sits in the shed too long and I notice it can be harder to start after a while. It's not going to cost me much extra a year and will hopefully be better for the saw in the long run

 

No worries, glad it worked, that drop in revs when yanking the throttle in is caused by slightly leaning out before the main jet kicks in and is typical of the L screw being slightly lean causing mid range lag.

 

Seen it before, all good, another issue sorted:thumbup: