046 Tuning

[Brushswamper523]

Good Morning All,
Finally put the top end and got all the parts for my 046 put it together. I am having issue getting it in tune. Every once in awhile after I release the throttle it will sound like it leans out and dies but it isn't consistent. It doesn't do it all the time. I have a newly rebuilt carb. And the top end is new. Any suggestions on what to do? Tuning is my kryptanite in chain saws. I did put at tac on it and it is idling between 2500-2700 rpm and the high is a little low 12500( I beleave 13500 is where it should be around). Any help would be great guys.

 

[Mad Professor]

What parts did you replace? If you are sure all the rubber and seals are good/new (pres/vac test?) check the cyl bolts and intake boot clamp. Also impulse line/fuel line connections. Sounds like air is getting in someplace

 

[tomalophicon]

Good Morning All,
Finally put the top end and got all the parts for my 046 put it together. I am having issue getting it in tune. Every once in awhile after I release the throttle it will sound like it leans out and dies but it isn't consistent. It doesn't do it all the time. I have a newly rebuilt carb. And the top end is new. Any suggestions on what to do? Tuning is my kryptanite in chain saws. I did put at tac on it and it is idling between 2500-2700 rpm and the high is a little low 12500( I beleave 13500 is where it should be around). Any help would be great guys.

A similar thing was happening to my Makita. Needed a richer L mixture.

 

[Maintenance supervisor]

Could be a pin hole in the fuel line , a defective fuel filter or lever in the carb set to low.
Honestly these are things I have run in to and check now .
Will it stay running with the choke on? How many turns out on the jets of the carb?

 

[Brushswamper523]

Thanks guys. So the only pieces that aren't new is the intake boot and impulse line. The jets are as follows low jet is 1 1/4 turn out and the high is 1 turn out. I am going to order a new impulse line and I have another intake boot to try. I checked the cylinder bolts all good there. It will not run with the choke on as far as I know. Should I try flipping it into choke at idle?

 

[lone wolf]

Thanks guys. So the only pieces that aren't new is the intake boot and impulse line. The jets are as follows low jet is 1 1/4 turn out and the high is 1 turn out. I am going to order a new impulse line and I have another intake boot to try. I checked the cylinder bolts all good there. It will not run with the choke on as far as I know. Should I try flipping it into choke at idle?

Does it say on the saw to put the low at 1.25 turns out? If not try 1 turn out.

 

[JonCraig]

Why a new top end? What cooked the old one? Crank seals are cheap insurance on a saw as old as an 046 (as are the intake boot and impulse line...)

 

[Vintage Engine Repairs]

“Steve small engine saloon” has a good saw tuning video.

 

[Brushswamper523]

I checked the seals, we'll at least from the outside, there was no play in them. The exhaust side had some very bad scoring intake side completely clean. My guess would be some one leaned it out and got it hot. I did ordered a new intake boot and impulse line. Just waiting for those to come in. I misspoke on the turns they are both 1 turn out, I checked today. It seems like it is idling better today after some time idling some fuel through it but still would like to figure it out. I will change those parts when they come in and keep you guys posted. Appreciate the help so far and I am sure we can figure this out.

 

[tomalophicon]

I'd be inclined to check the low screw. As I said mine was experiencing very similar symptoms and I needed more fuel on the low side.
Tom

 

[drf255]

I checked the seals, we'll at least from the outside, there was no play in them. The exhaust side had some very bad scoring intake side completely clean. My guess would be some one leaned it out and got it hot. I did ordered a new intake boot and impulse line. Just waiting for those to come in. I misspoke on the turns they are both 1 turn out, I checked today. It seems like it is idling better today after some time idling some fuel through it but still would like to figure it out. I will change those parts when they come in and keep you guys posted. Appreciate the help so far and I am sure we can figure this out.

Only way to check the seals is by vacuum/pressure checking them. “Play” in them would mean a bad bearing, which in turn would take the seal out. You can’t visually check a small seal leak.

 

[Brushswamper523]

Only way to check the seals is by vacuum/pressure checking them. “Play” in them would mean a bad bearing, which in turn would take the seal out. You can’t visually check a small seal leak.

Thanks I will look into getting a check I will have to see if a shop around me has the ability to do it since I do not.

I'd be inclined to check the low screw. As I said mine was experiencing very similar symptoms and I needed more fuel on the low side.
Tom

I will give this a shot today thanks.

 

[Yukon Stihl]

There was a reason it scored the first time
You have to find out why and remedy the cause,or you will repeat the scored piston.
Vacuum and pressure test is a must.Should always be step one with a scored piston or a saw that isn’t running right.