Mac 3516 chainsaw?

[Sawdust76]

New member, Thanks.
What I have done so far.
1. Replaced disintegrated oil pickup tube. Was spewing bar oil.
2. Cleaned carb with carb cleaner getting all openings.
3. Purchased rebuild kit. Installed kit, still no start.
4. Chainsaw has a Walbro WT347. Not available.
5. New spark plug, have spark as well with previous plug.
6. Replaced gas tank filter with a new filter.
7. Purchased new carb. from Amazon. Still no start.
8. Opened up low jet, started up under half throttle, engine died when released. Engine will not start. Sprayed a little Starting fluid into choke opening. Still would not start.
Am I missing something???
What should the H and L needle settings be to get this engine working again?

I understand the H and L settings might need tweaking under load.
All help is appreciated.

 

[whybother]

I usually set the H & L needles 1 turn out to start with.
Are you checking the plug to see if it's wet/flooded when it won't start?

 

[FergusonTO35]

Have you checked compression? Compression may be low enough to only sometimes run, most cheaper 2 stroke engines are pretty modest to begin with.

 

[whybother]

Another thought, have you pressure/vacuum tested it for air leaks?

 

[hacskaroly]

Opened up low jet, started up under half throttle, engine died when released. Engine will not start. Sprayed a little Starting fluid into choke opening.

Hello and welcome to the forum!! A quick recommendation, next time use WD-40 instead of starting fluid (ether), WD-40 has lube in it, starting fluid is all fire. 2 strokes like their lube in their fuel! Good to hear you have spark and with other stuff you have done, eliminated some of the other potential issues. Does your purge/primer move fuel? Clean air filter? Spark arrestor plugged/clean? I am assuming you are using fresh fuel (either what you mixed or can gas).

Initial carb settings to try: L: 1.5 turns counter-clockwise from seating, H: 1.5 turns counter-clockwise from seating. You can turn the idle screw in enough to get the saw started and then back it off as needed until the chain stops spinning.

From a cold start steps should be (I have a Mac 3200 and this is what I do):
1. Press purge until you get fuel
2. On/Off switch - On
3. Set full choke setting
4. Lock trigger to full throttle
5. Pull until saw burbles or starts (if it starts it will run rough - you can close choke lever)
6. If the saw burbled but didn't start, close the choke and pull again until start.
7. When the saw starts, blip the trigger to drop it from running full throttle.
8. If the saw quits, you may need to adjust the idle screw more to get it to keep running on the next start.
9. You may have to keep starting the saw with the trigger locked to full throttle until you get the idle screw in the correct position.
10. Once running off of full throttle, you can adjust the idle screw down, wait for the saw to warm and then work on adjusting the H/L setting.

Like others have said, it is possible you may have an air leak or a compression issue (you can pull the muffler and inspect the piston for any scorring - if it looks nice and shiny with no vertical lines, you should be good to go there).

Good luck, let us know what you find out!

 

[Sawdust76]

Have you checked compression? Compression may be low enough to only sometimes run, most cheaper 2 stroke engines are pretty modest to begin with.

Compression was at 124 psi.

 

[whybother]

Compression was at 124 psi.

124 is on the low side, however it should run with that. Did you pull the muffler and check for scoring?
I'd pressure/vac test it and check the crank seals for air leaks as long as you don't see scoring when you pull the muffler and check piston and cylinder.
I'd also put the stock carb back on. I've had no luck the aftermarket ones at all, so I'm probably jaded.

 

[Sawdust76]

124 is on the low side, however it should run with that. Did you pull the muffler and check for scoring?
I'd pressure/vac test it and check the crank seals for air leaks as long as you don't see scoring when you pull the muffler and check piston and cylinder.
I'd also put the stock carb back on. I've had no luck the aftermarket ones at all, so I'm probably jaded.I have given it up on this saw. have put the original Walbro carb back on the saw. It was picked up by the owner. I am not happy about that.

I have reinstalled the original Walbro to the saw. The owner picked up his saw today. I asked him to start the saw. It did start with some difficultly. I asked to keep it running for a bit. Saw was then shut off. Saw would not restart, just like I have experienced.

I have given up on this saw, I have Way too much time on this saw. Glad to see it go.
I do not like to admit defeat.

A BIG thank you to those that have replied.




A BIG thank you to those who have replied.

 

[hacskaroly]

A BIG thank you to those that have replied.

Don't be a stranger...it happens. I have a small Poulan that's kicking my butt, I had the hardest time getting it to kick over after pulling it all apart (it was running before, I just wanted to see how it worked - first clamshell I have torn apart). Fourth time getting it back together, I finally got it to turn over, but won't run long before dying out. I have put it on the shelf for now. I will take a look at it later with fresh eyes...It happens!

 

[Wood Doctor]

I have two small Macs that still run well today: a 3516 and the Mac Silver Eagle. Some small saws never die. Just MHO.

 

[FergusonTO35]

I have reinstalled the original Walbro to the saw. The owner picked up his saw today. I asked him to start the saw. It did start with some difficultly. I asked to keep it running for a bit. Saw was then shut off. Saw would not restart, just like I have experienced.

I have given up on this saw, I have Way too much time on this saw. Glad to see it go.
I do not like to admit defeat.

A BIG thank you to those that have replied.




A BIG thank you to those who have replied.

I hate letting a machine beat me. Yes, I know its not a valuable use of time and money but I hate it just the same. Carburetors are my sworn enemy, gimme EFI any day.