KennyPete
ArboristSite Operative
Glad I can help Keith.
Husqvarna 257 acting funny
- Thread starter Keithandstef
- Start date
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Keithandstef
ArboristSite Operative
I don't know, that decompression valve cleaning seems to have upped the pull cord resistance. I don't have the saw back together yet, but the difference in pull tension between compression valve depressed and not depressed is much more noticeable now. I wonder if something got lodged in there during all that cutting (where have I read that before, hmmmm). Wouldn't be the first time you guys were right. Will report back later this week.
Keithandstef
ArboristSite Operative
Just went out and hooked it up to the compression tester. 135 the first time I tested it. Did it a second time and it was 120. A little lower than the 140 it ran (not on my tester) before I bought it. I never base-lined it on my own tester after I bought it (darn it). Is it normal for a saw to test a little lower on two consecutive cold tests?
calebng15
Always lookin' for somthing to cut!
Are you pulling it till the gauge quits going up?
The more you futz with it without actually running it, the lower the compression will get. Your fuel is your lubricant and turning it over without running it will wash down the cylinder walls and give lower than actual compression.
Keithandstef
ArboristSite Operative
Yes. I probably stopped after ten or so pulls.
Keithandstef
ArboristSite Operative
I've been messing with it quite a bit lately over the past couple days (testing the cord) but have not actually run it. Odd though that I would get two such different readings (135 vs 120 psi) only a minute apart.
KennyPete
ArboristSite Operative
Put a drop or two of 2 cycle oil down in the spark plug hole, it will lubricate it and give an accurate reading.
KennyPete
ArboristSite Operative
jr27236
Addicted to ArboristSite
I hate when these threads go dead and leave us hanging. I think half these guys right for my local paper, they never finish a story either.
Update please.......I need reading material, I canceled my paper. Lol
Update please.......I need reading material, I canceled my paper. Lol
KennyPete
ArboristSite Operative
The thread isn't dead persay. He sent it to me as he mentioned earlier. It's going to get some bench time this weekend, I will keep you posted.
KennyPete
ArboristSite Operative
Since I know you're dying for a money shot..
Going to break her down next week and put a new ring in her, see how she does.
Going to break her down next week and put a new ring in her, see how she does.
Keithandstef
ArboristSite Operative
Kennypete = my hero. 
jr27236
Addicted to ArboristSite
Next week!!!! That picture isn't going to hold me off till next week!!! LOL
Come on crack her chest open.
Keithandstef
ArboristSite Operative
Sounds like I may have run her too lean for the work we were doing, meaning I should have gone with something richer than a 50:1 ratio. Lesson learned. Hopefully it's just the ring as Kennypete suspects. Patience grasshoppers, he'll let us know in due time.
cedarshark
Addicted to ArboristSite
I think I would unscrew that decomp and float test it in a pond. Put a plug in it and then retest. It's a 57cc saw....no decomp necessary.
Keithandstef
ArboristSite Operative
Kenny Pete gave me an update and sent a picture (that I'm having a tough time posting from work) of the compression now at 150 psi (yeah!!). Kenny noted the following:
1) Piston looks great
2) Cylinder has been previously honed and has a couple tiny horizontal scratches; one intake side and one exhaust side. He wasn't sure if these could be adding to the previous compression problem. I mentioned to him it ran at 140 psi before I purchased it, so it was decent until I apparently ran it too hard and lean. He said we could do a new cylinder or just try the ring. We went ring only and got 150 psi. I'm fully good with that. I bet that saw never got above 160 PSI new.
3) The ring it had in it looked OK, but didn't appear to be OEM. The one he put in is OEM.
I'm going to run it a little more gently for a bit and with a closer to 1:33 mix ratio during break in. Hopefully I can keep the compression up. If not, I guess a new cylinder is in order someday.
So, he's getting her back together and will be sending her home. Kenny has been such a great help and very knowledgeable. I think the diagnosis was free and I'm happy to pay his fix-it rate, parts and shipping of course.
Case closed it seems.
1) Piston looks great
2) Cylinder has been previously honed and has a couple tiny horizontal scratches; one intake side and one exhaust side. He wasn't sure if these could be adding to the previous compression problem. I mentioned to him it ran at 140 psi before I purchased it, so it was decent until I apparently ran it too hard and lean. He said we could do a new cylinder or just try the ring. We went ring only and got 150 psi. I'm fully good with that. I bet that saw never got above 160 PSI new.
3) The ring it had in it looked OK, but didn't appear to be OEM. The one he put in is OEM.
I'm going to run it a little more gently for a bit and with a closer to 1:33 mix ratio during break in. Hopefully I can keep the compression up. If not, I guess a new cylinder is in order someday.
So, he's getting her back together and will be sending her home. Kenny has been such a great help and very knowledgeable. I think the diagnosis was free and I'm happy to pay his fix-it rate, parts and shipping of course.
Case closed it seems.
