Chainsaw Repair
Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Partner => Topic started by: The Ripper on September 21, 2015, 08:26:09 pm
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Lost compression and after disassembly I found a broken ring,so I ordered a new assembly but I'm unable to remove piston pin. Are there any tricks in removing the pin or should I just install the new rings from the new piston to old piston?
Also are there any suggestive mods to increase the oil volume to the bar?
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Cant get the pin off the rod knocking it through from one side of piston? Is it a pressed in pin I wonder?
Dont hit me, but did you remove circlips?
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The above and, shoot some WD40 in there to break up the fuel/oil varnish.
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Yes I removed pin clips and am now soaking it in hopes of breaking it loose.
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Got the new piston installed,compression down just a bit,hopefully that'll increase once the rings get seated.
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I don't know how much compression is to much but after a few tanks of gas and the rings seating,I finally got my compression gage out and the compression sets right at 200 PSI. ( I triple checked it ) The aftermarket piston has a slightly higher dome which accounts for the extra 25 psi increase. I gotta tell this R16 is just a beast will all kinds of torque and wants to be run on the very edge of being lean other wise it looses power. I use HR1 mixed at 32.1 for insurance. This is a definite keeper. Now it's on to the 3.7 rebuild.
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The main disadvantage of the R16 vs. most later models of basically the same design is that it lacks any kind of AV.
Check the squish of that saw, it may be too tight.
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The squish is .024. Compression was 175 after deleting base gasket and bumped up after installing new piston. As for the AV,this saw is very smooth running in the cut believe it or not unlike some non av, which is why I plan on keeping it.
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I don't think there is much you can do about those oil pumps and the output. I've an F55 in need of a new pump. It is an odd design. A rod drives against a band of spring steel with a tooth that engages the pump "gear". The surface of the gear and tooth were worn to the point they slipped. I attempted to dress the tooth on the band and bend it. It fatigued and broke. Unless those two mating surfaces engage continuously, you will have no, little, or sporadic flow. When healthy, the oil output is more than adequate. I'd a Skil version I fixed up for my father and it slung the oil well.
I suspect the end of the rod that drives the band gets worn over time and provides less and less travel. It too can limit the effectiveness of the pump.
I've been on the lookout for an affordable replacement for some time. No dice.