Yeap I'll throw it on in the next few days I'm putting her back together for a while got some trees for next weekend so need my saws running. Then I'll do the rings
McCulloch Chain Saws
- Thread starter Bruce Hopf
- Start date
Help Support Arborist Forum:
Thanks again mate
Ive got 2 different ipls for pm700. Both show thin rings #89732. Same number for 7-10 thin rings.
Ok good as I'll get some ordered. Perhaps I should just do the piston too but the pressed pin is disturbing me a bit
If you support it properly and get a socket the right size itll come out with a hammer just fine. Freeze the wrist pin and heat the piston and do the same support with a socket and hammer itll go back in just fine also. Ive done 2 that way. Worked ok first time and better the second. You can do it. Heck you made a muffler. You can pop a wrist pin in and out.
Heat the rod too i should say
Yea ok I'm being a wuss lol I can do it for sure. Thanks for the instructions fella's
Not a wuss. You just havent done that yet. The best thing is preparation. Have everything ready to go will make a big difference.
True I'm just used to clips I see a few guys made up a cradle with wood I like that idea.
If I can remember, I will take a photo of the simple pin press I made from some scraps of pipe and nut and a long bolt. Either that, or just find a small arbor press, while I've done it with a hammer and driver, I prefer to press. Heating the rod before assembly is not 100% required but does spare the parts in case you have to repeat the operation such as when you put the piston on the wrong way, I guess...
A C clamp with a couple of sockets can also work but requires more hands than I have.
Mark
A C clamp with a couple of sockets can also work but requires more hands than I have.
Mark
Thanks mark I spose a press is a good idea especially for you I bet you've done an uncountable number of them by now
Ok guys can anyone tell me the differences between the 70cc pistons? Is the ring thickness the only thing or are the windows in them different to suit the different porting of the 7-10 vs 700?
- Joined
- Jul 20, 2014
- Messages
- 1,882
- Reaction score
- 2,527
Kevin - message received. I will get on it when I am back the first week of April.
Jethro - There are significant differences in the 70cc pistons. Older models (4-10, 5-10, 6-10) were window less, the 7-10, CP70, SP70, and PM700 were windowed. Thin ring were generally considered to be better performers in the short term, thick ring may be a little less peppy but hold their performance over a longer period. 85239 is the thin ring windowed piston used on the 7-10, CP70, SP70, and PM700 models, 85240 is a windowed (I think thick ring) piston used on some 6-10 and 7-10 models. The window less piston is 69412 and uses 63290 thick rings. My 7-10 that I use a lot has thick rings but the one shown below has thin rings. The window less piston is used on the 4-10, 5-10, and some 6-10 saws. I have not tried to examine all of the G models so I don't know which piston/ring combinations were used on those saws.
Mark
Jethro - There are significant differences in the 70cc pistons. Older models (4-10, 5-10, 6-10) were window less, the 7-10, CP70, SP70, and PM700 were windowed. Thin ring were generally considered to be better performers in the short term, thick ring may be a little less peppy but hold their performance over a longer period. 85239 is the thin ring windowed piston used on the 7-10, CP70, SP70, and PM700 models, 85240 is a windowed (I think thick ring) piston used on some 6-10 and 7-10 models. The window less piston is 69412 and uses 63290 thick rings. My 7-10 that I use a lot has thick rings but the one shown below has thin rings. The window less piston is used on the 4-10, 5-10, and some 6-10 saws. I have not tried to examine all of the G models so I don't know which piston/ring combinations were used on those saws.
Mark
Thank you Mark that's exactly the info I was after.
Just a follow up on my Timberbear.I was going to do a compression test on it today,but after wrestling with the tester for about 10 min.I abandoned that idea.I put a different carb on it & it fired right up.I came to the conclusion that the needle was stuck not allowing any fuel into the carb.
Also I had some success with a 7-10 that I couldn't get to fire up last month.I'll take the carb off & rebuild it.Previously I thought I could get away with just a cleaning,apparently I was wrong.I hope to have it operational with a 24 in.bar & chain tomorrow.
Ed
Also I had some success with a 7-10 that I couldn't get to fire up last month.I'll take the carb off & rebuild it.Previously I thought I could get away with just a cleaning,apparently I was wrong.I hope to have it operational with a 24 in.bar & chain tomorrow.
Ed
Yeah,so much for the success on the 7-10.I'm right with you Kevin on this.The saw fired up yesterday,it ran like crap,but it ran.Today I gave it a bunch of goodies - a new sawdust screen,a carb rebuild along with a new carb boot that was missing (yes,that's what the square tube that goes to the needles is called).I got it all together & it refused to even pop.I guess I'll let it set for another 3 weeks & then maybe it'll run again.
Ed
Ed
- Joined
- Jul 20, 2014
- Messages
- 1,882
- Reaction score
- 2,527
I'm working on rebuilding the tillotson HL19D that came with my 1-86. I bought an RK88HL kit. This carb has an extra welch plug that did not come in the kit. I am also curious what that little brass plug looking thing is next to the small welch plug. Anyone have any insight? Thinking of just leaving that welch plug alone unless someone has one kicking around.
Yeah Kevin,I ran into that on an old HL48A carb that was on my Homelite Zip.Normally I don't bother with welch plugs & I've had good success.
Ed
Ed
