Meteor PC Kit Surprises

[JoeMay]

White topped Husqvarna 61 Practica would start and run but not well or for long. I got the saw for free as compensation for work I did on a neighbor's Husky 141. Discovered the 61 to have a scored piston and cylinder; see photos. Likely from ingesting debris because the carb had debris in it. This 61 will go to a brother of mine as a housewarming gift. So I opted to get a Meteor PC kit vs cleaning up the damaged OE PC. The transfers of OE cylinder are vastly different that those of the Meteor; see photo. The base of the Meteor cylinder has a protrusion to accommodate the different transfer port design. So it is wider at the base than the OE is; see same photo. This extra width proved a bit of a problem because the flywheel perimeter rubbed against the wider base of the Meteor cylinder; see photo. This was easily fixed with light and careful filing. Lastly, the wrist pin areas of Meteor piston (smooth) are much different than those of the OE (cut away); see photos. The Meteor PC kit was installed with trepidation. Everything test fit and hand rotated smoothly. Compression checked out to be around 150; see photo. Initial start up was uneventful and it ran well. I've tested daily 3 times since work was done and it continues to start right up and run well. I feel OK about giving this one to my brother. If it acts up I'm not far away from him.

 

[J D]

I believe the early 61’s were open transfer, windowed piston as your OE was. Your meteor kit is probably based of the later 61 PC... That should mean it goes a little better

 

[JoeMay]

Yes OE cylinder has open transfer ports. Now I have a full and real understanding of open vs closed transfer ports. I''m keeping it rich for a while for break in. Couple of short stints at WOT showed 11,750 rpm on the tach. Idle is set and holds very well around 2,500 rpm.

 

[Huskvarna hotellgäst]

Neither cylinder has "closed" transfer ports. Likely no difference in performance due to alternate design.

 

[JoeMay]

A brief explanation or even pictures of open vs closed transfer ports would be much appreciated. I thank you for your input.

 

[JoeMay]

I found a good explanation right here on the arboristsite -

Open port/ closed port?​

• Thread starterTrigger Man
• Start dateDec 13, 2009
• TagsNone

Based on this, both cylinders would be open transfer port designs. However, that Meteor cylinder does have well defined transfer port windows while the OE cylinder does not.

 

[Huskvarna hotellgäst]

A brief explanation or even pictures of open vs closed transfer ports would be much appreciated. I thank you for your input.

A "closed port" cylinder has sand-cast transfer ports, usually curved and with a decreasing cross-section so that the mixture is accelerated as it passes through.
The piston has either openings or cutouts in either side of the skirt, the size and positioning of which controls the timing of entry of the incoming fuel mixture into the transfer ports.

Open port cylinders are cheaper to cast (a) because there's nothing to clear out and discard, and (b) casting flaws (due to the molten alloy solidifying too quickly in the relatively small areas) are greatly diminished.

 

[JoeMay]

Thank you for the explanation and information.