Stihl 021 carb tuning help

[Jonesy11]

Fixing a stihl 021 for a relative. Just needed a carb kit. I am having trouble tuning it though. The crappy one screw carb in giving me problems.

It is running at idle but when you rev it up it will only go to about half throttle and start to die out. It kind of bounces off the high side like starving for fuel?

Guess my rookie mistake is, is it the carb tuning or the gas line collapsing? thoughts?

Going to check back tomorrow when I have time to get down to look at the gas line.

 

[pioneerguy600]

Seen this a few times if the impulse line is not hooked up.

 

[Rockjock]

My 021 came with the WT- 215 carb So it is fully tunable and not a bad upgrade . Impulse line is incorporated in the intake boot. . I suggest you go through the carb again. any q's just ask

 

[pioneerguy600]

My 021 came with the WT- 215 carb So it is fully tunable and not a bad upgrade . Impulse line is incorporated in the intake boot. . I suggest you go through the carb again. any q's just ask

I am fairly certain the ones I worked on have a separate impulse line.

 

[Rockjock]

I am fairly certain the ones I worked on have a separate impulse line.

http://www.arboristsite.com/community/threads/stihl-021-teardown-with-pics-and-questions.97588/

 

[pioneerguy600]

http://www.arboristsite.com/community/threads/stihl-021-teardown-with-pics-and-questions.97588/

See the separate line hooked up to the nipple on the cylinder base. ..part number 1123 141 8600

 

[Rockjock]

See the separate line hooked up to the nipple on the cylinder base. ..part number 1123 141 8600

yes yes I do see that but am perplexed The 021 came with several carbs and looking at the IPL I am not seeing an implse line connection. And yet it is there in the link. Been a while since I tore into one so could be wrong. Did a ebay search for carbs and found this.. no impulse nipple
http://www.ebay.com/itm/STIHL-210-2...894?pt=LH_DefaultDomain_0&hash=item4adcb56f26

 

[pioneerguy600]

I have worked on several of them, on one the line was split at the nipple and the saw would run at idle, just a tad fast but when the trigger was pulled it would start to rev up but then fuel starve, the other one with similar symptoms the line had disconnected at the back of the rubber manifold. Strange thing was that the engine did not idle fast, would start quite easily but wouldn`t spool up. Now there may be something else going on with the OP`s saw but checking the impulse line is something he can check out. Could be an internal carb problem , partial blockage of the high speed circuit, metering lever set too low , bad fuel pickup line or tank filter.

 

[pioneerguy600]

yes yes I do see that but am perplexed The 021 came with several carbs and looking at the IPL I am not seeing an implse line connection. And yet it is there in the link. Been a while since I tore into one so could be wrong. Did a ebay search for carbs and found this.. no impulse nipple
http://www.ebay.com/itm/STIHL-210-2...894?pt=LH_DefaultDomain_0&hash=item4adcb56f26

The impulse line does not connect to the carb, it connects to the backside of the intake manifold and runs down to a nipple on the cylinder base.

 

[AKDoug]

I agree with Pioneerguy600 and I would check that first. However the symptoms the OP describes is also very common when the carbs just finally give up the ghost. A quick $30 application of a WT215 cures it quickly.

 

[Rockjock]

The impulse line does not connect to the carb, it connects to the backside of the intake manifold and runs down to a nipple on the cylinder base.

well that explains that!!! I never tore into mine that far! Thanks I have now learned something new!!

 

[pioneerguy600]

I agree with Pioneerguy600 and I would check that first. However the symptoms the OP describes is also very common when the carbs just finally give up the ghost. A quick $30 application of a WT215 cures it quickly.

After I check out all the things I listed in my post a couple above this # 8,that is what I would suggest also.

 

[pioneerguy600]

well that explains that!!! I never tore into mine that far! Thanks I have now learned something new!!

I learn something new most every day, sometimes several new things and make my share of mistakes along the way...LOL

 

[w8ye]

I have three of this family of Stihl.

The impulse line connects to a nipple on the base of the cylinder and goes through a hole in the plastic heat shield and then connects to another nibble at the end of the boot near the carb.

The impulse line has to be finally connected by reaching under and through some things with the needle nose pliers.

I had one that the line was almost off the nipple and would cause very irregular running.

I have WT-215 carbs on all of them for the carb is only $22.50 from Stihl.

A few years ago one saw still had the single needle carb. The low speed needle had more of an effect on the high speed than you would think?

 

[drf255]

I have three of this family of Stihl.

The impulse line connects to a nipple on the base of the cylinder and goes through a hole in the plastic heat shield and then connects to another nibble at the end of the boot near the carb.

The impulse line has to be finally connected by reaching under and through some things with the needle nose pliers.

I had one that the line was almost off the nipple and would cause very irregular running.

I have WT-215 carbs on all of them for the carb is only $22.50 from Stihl.

A few years ago one saw still had the single needle carb. The low speed needle had more of an effect on the high speed than you would think?

I'd like to buy a few WT215's.

Where do you order from Stihl online?

I must say though, I installed a $12 shipped Chinese knockoff on a saw and It worked great.

 

[w8ye]

You cannot get Stihl on line.

There are 7 Stihl dealers within 20 mi of my house and 3 within 5 miles.

You have to go to the dealer to get a new one.

 

[Jonesy11]

Just a double check while waiting for fuel line to arrive. On the diaphram there is a silver wheel on one side and just a center nipple on the other. Which side should face the carb?

 

[w8ye]

The button goes towards the lever

 

[pioneerguy600]

Metal disc faces the carb body.

 

[Jonesy11]

Thanks all. Finally got it done. Swapped the gas line and fired it up with no change of revving past half throttle. Opened up carb and swapped the two bottom side gaskets and now runs great. Throttles up and stays running. $10 cost and learned some things in the process. Not a bad day.