Mcculloch PM 555 - White smoke cloud

Vanguard

Vanguard

ArboristSite Lurker
Joined
Jan 21, 2021
Messages
45
Location
USA - Originally Grays Harbor
Picked up a Pro Mac 555 the other day, and it's blowing clouds of white smoke through muffler. I also noticed mix running out of muffler too.

This started on first fire up after going over saw. Smokes during idle but even more with throttle. After it warms up with some throttle the smoke clears up, but then comes back with throttle or tilting saw on bar/muffler side.

I'm leaning towards carb issue, possibly inlet needle. Carb looks to have been rebuilt, visually clean inside with new gaskets, and the metering lever was set at proper height after checking with Walbro SDC Gauge. Jets were 1 1/4 turns or less after bench tuning a little, idles smooth at 2700 RPMs and will 4-Stroke at high RPMs with great throttle response... no eradit RPMs otherwise.

Looks to be a clean looking saw all around... cylinder and piston looks good through both intake and exhaust ports, case bolts look snug, crank seals with no play, exhaust decarbonized, and doesn't look abused or much wear and tear one would expect for age of saw.

Never had a saw create a smoke show this bad before... just want to make sure I'm not missing something before using a carb rebuild kit and possibly a check valve kit, and gaskets.

Thanks
 
olyman

olyman

Tree Freak
Joined
Jul 29, 2006
Messages
25,118
Location
iowa
Picked up a Pro Mac 555 the other day, and it's blowing clouds of white smoke through muffler. I also noticed mix running out of muffler too.

This started on first fire up after going over saw. Smokes during idle but even more with throttle. After it warms up with some throttle the smoke clears up, but then comes back with throttle or tilting saw on bar/muffler side.

I'm leaning towards carb issue, possibly inlet needle. Carb looks to have been rebuilt, visually clean inside with new gaskets, and the metering lever was set at proper height after checking with Walbro SDC Gauge. Jets were 1 1/4 turns or less after bench tuning a little, idles smooth at 2700 RPMs and will 4-Stroke at high RPMs with great throttle response... no eradit RPMs otherwise.

Looks to be a clean looking saw all around... cylinder and piston looks good through both intake and exhaust ports, case bolts look snug, crank seals with no play, exhaust decarbonized, and doesn't look abused or much wear and tear one would expect for age of saw.

Never had a saw create a smoke show this bad before... just want to make sure I'm not missing something before using a carb rebuild kit and possibly a check valve kit, and gaskets.

Thanks
hopefully mheinmann will see this thread...………..
 
Vanguard

Vanguard

ArboristSite Lurker
Joined
Jan 21, 2021
Messages
45
Location
USA - Originally Grays Harbor
Think I found the problem... emptied the bar oil, and white smoke is gone after burning residual oil in cylinder, even when turning saw on bar/ muffler side.

I also took oil reservoir cover off, saw starts racing with throttle applied... definitely an air leak inside reservoir.

The 4 case bolts and automatic oiler screw feels very snug. Case bolts looked untouched and tight against oil resevoire. I'm guessing the oiler gasket is needing replaced... more so since turning the saw on bar side, immersing the oiler gasket.

Curious if anyone here has had same problem, findings being oiler gasket or case bolts.

Thanks
 
heimannm

heimannm

Tree Freak
Joined
Dec 28, 2005
Messages
10,994
Location
Dike, Iowa
Very likely the seal on the automatic oil pump is leaking allowing bar oil to be pulled into the crankcase. You will need to pull the cover off the oil tank and look for the steel clip that probably shook loose. Search the McCulloch Chainsaw thread or the McCulloch 10-10 thread for more information.

DSC01461.JPG

Seal and clip

DSC02761.JPG

DSCN5918.JPG


Mark
 
Vanguard

Vanguard

ArboristSite Lurker
Joined
Jan 21, 2021
Messages
45
Location
USA - Originally Grays Harbor
Very likely the seal on the automatic oil pump is leaking allowing bar oil to be pulled into the crankcase. You will need to pull the cover off the oil tank and look for the steel clip that probably shook loose. Search the McCulloch Chainsaw thread or the McCulloch 10-10 thread for more information.

View attachment 914868

Seal and clip

View attachment 914869

View attachment 914870


Mark
Thanks for the input... no steel clip in reservoir, but looking in one of my MAC 10-10A I see a steel clip on bottom of resevoir probably an alteration of what your documenting shows? I also noticed the oiler is missing the lock nut for oiler adjustment bolt on the PM 555 as well.
 

Attachments

  • 20210625_112453.jpg
    20210625_112453.jpg
    1.2 MB · Views: 11
  • 20210625_112504.jpg
    20210625_112504.jpg
    1.3 MB · Views: 11
heimannm

heimannm

Tree Freak
Joined
Dec 28, 2005
Messages
10,994
Location
Dike, Iowa
The spring under the adjuster screw was another attempt to seal the pump body. It was suppose to press the pump body down to create a more effective sealing action but it was not very effective.

DSCN5931.JPG

Mark
 
Vanguard

Vanguard

ArboristSite Lurker
Joined
Jan 21, 2021
Messages
45
Location
USA - Originally Grays Harbor
The spring under the adjuster screw was another attempt to seal the pump body. It was suppose to press the pump body down to create a more effective sealing action but it was not very effective.

View attachment 914873

Mark
This Felpro gasket might have not helped issues as well... not as good as black forming felt type. Any idea on getting one of those clips? No luck searching online, Ebay, etc.

Otherwise, power head alone runs great, able to bench tune without bar oil, thus no smoke. Can't imagine oil leaking through case bolts, looks clean and untouched.
 

Attachments

  • 20210625_174422.jpg
    20210625_174422.jpg
    1.6 MB · Views: 5
  • 20210625_174512.jpg
    20210625_174512.jpg
    3.9 MB · Views: 5
heimannm

heimannm

Tree Freak
Joined
Dec 28, 2005
Messages
10,994
Location
Dike, Iowa
Try looking for 215246, that is the full kit with the new hard rubber seal, the spring clip, and two brass eyelets to install in the pump to prevent the steel clip from digging into the plastic pump body. The spring clip does not have a part number by itself that I know of.

Mark
 
Vanguard

Vanguard

ArboristSite Lurker
Joined
Jan 21, 2021
Messages
45
Location
USA - Originally Grays Harbor
Try looking for 215246, that is the full kit with the new hard rubber seal, the spring clip, and two brass eyelets to install in the pump to prevent the steel clip from digging into the plastic pump body. The spring clip does not have a part number by itself that I know of.

Mark
16250974439493147839934626199602.jpg
Got the rubber seal in. Curious if you installed this with oiler having the spring steel you posted above? Instructions states to remove... I took oiler from a 10-10 having spring steel and was able install, no smoke so far. Just wondering if you tried same combination and had issues?
 
heimannm

heimannm

Tree Freak
Joined
Dec 28, 2005
Messages
10,994
Location
Dike, Iowa
I have tried the spring on top of the pump rather than the clip behind the pump but it was not effective for me. If it worked for you, that's great. On other saws I have resorted to drilling the two extra holes and installing the pump with three screws like the early ones. That works best with an aluminum body automatic oil pump.

DSC04075.JPG

DSC04076.JPG

Mark
 
Top