Several weeks ago I came upon a Shindiawa 575 chainsaw with a 20” bar and chain. Free if I wanted it. It had sat in a barn unused for at least 15 years. I was told it didn’t run and was too heavy for the older man to use. It looked pretty rough covered in years of dust and grime. But the price was right and I figured “what the heck”, if it’s junk nothing ventured. At home under closer inspection found that the fuel line was shot, fuel filter plugged, carburetor gummed up, small hole in the gas tank… just an oily, grimy mess! The piston and cylinder walls looked great and spark plug looked good. Upon pulling there was spark. So… took it apart and cleaned the whole saw, cleaned and rebuilt the carb, new fuel filter and line, cleaned the air filter, JB Weld on the fuel tank hole, flushed the tank, cleaned the bar, sharpened the chain, tuned it using a tachometer… it runs and cuts great! Except… and here is where I’m perplexed… whether it’s the first start of the day or starting five minutes after running hard for a half hour… unless you let it sit and idle for a couple minutes it bogs badly upon acceleration. After it sits and idles for a couple minutes it runs and cuts like a beast! This happens every start, every time. What could be the problem?! I really like this old saw I resurrected. Sorry for the long post
Does a small adjustment in or out to the L screw make any difference? Nice looking saw. I think Shindaiwa was the first saw I ever ran.
Small adjustments on the L screw doesn’t seem to make a difference. Interestingly, while it’s idling after being started the chain is turning. Once it’s ready to go, the chain no longer turns while idling. The most intriguing thing to me is once it idles for a few minutes, it runs perfectly. And idles great. Weird. I actually like this saw and enjoy using it.
Normally when you turn L screw clockwise/lean it will make the chain creep, so I’m wondering if you need to richen up L. Hopefully you don’t have an air leak somewhere.
Thanks Chud. Saw runs perfect, in any position, after it idles on start up. Maybe it’s need to idle when started is a feature, not an issue
I'd say the crank seals are old and stiff so they leak air when you first start it till they get enough oil on them to seal on the crank well. I’d buy crank seals and replace them.
Didn’t think of the crank seals but what you said makes sense. I think I’ll replace the seals. Thanks.
Before you go replacing anything, have the saw idling properly. Adjust the idle screw so that the saw stays idling but the chain does not move. Once you do that, take the bar and chain off. Leave it running idling and take a can of brake clean and spray in a couple of areas: 1 - Clutch area 2 - Intake manifold/connection to the carb 3 - Base of cylinder If the saw chokes and dies immediately after spraying then you have a found an air leak. An air leak can cause the saw to run intermittently - runs perfectly fine sometimes, other times just bogs or dies. Replacing seals is definitely possible but I would not start there. I'd also take the opportunity to replace the spark plug. Did not see you mention that. I had to fix this saw for my buddy. Wouldn't start and it was a massive air leak because the intake boot had popped out of place. Saw must have been dropped. Stihl MS193T.
I agree w/ Lehman. Saw of that age, seals are probably getting hard. Heat may be expanding metal somewhere to close a very small gap. Have you press/vac tested it? If not, I'd say do it when the saw is cold.
Personally all old saws I go over just get new seals to avoid them as an issue, he already did the whole fuel system so for 30$ or so I’d change seals and be done with it.
Personally don’t like brake clean for any of the air leak tests, very efficient degreaser and I like to keep oil in my bearings on the bottom end.
I had the same saw years ago , It was a great saw. The sound reminded me of an old dirt bike especially at idle. Used to refer to it as " Big Red"
Lots of good info. Thanks for sharing it all. This saw is old, but I really like using it. It does have a nice bark to it.
Just because you replaced stuff doesn't mean it's not the issue. One can miss thing sometimes or install the incorrectly. If you spray brake cleaner and there's a leak, then you need to replace the seal. So after you take off the old seal, you can ease your mind by pouring a few drops of 2-stroke in there. If you spray brake cleaner and there is NOT a leak, then no harm done because it ain't leaking. Yeah makes sense as the design the of the handle incorporated into the carb housing would make that easy to pop out......although one shouldn't be pinching a limbing saw too often I would imagine....unless you're using it to buck.....which you shouldn't......
I still pressure and vac test after the new seals the old brittle ones need to be replaced anyway because that seems to be the death of a large percentage of the old saws, as far as pinching a climbing saw it happens more than you think. I’m not a climber but fix saws for many tree guys and have done more than one set of stretched av springs from a branch trying to yank the saw out of the climbers hand. Use all the brake clean you want, but there’s a ton of other things you can use instead. Even a light spray of either will make the saw speed up if seals are leaking but I don’t do any of it just a pressure and vacuum test after I stick new seals in because it’s cheap insurance. Person will always be waiting and wondering when it’s going to start leaking or blow up. 20-25 year old seals in the saw are stiff and getting bad, I’ve pulled nos seals out of a package that are unusable from being old.
Thanks but no credit deserved. I learned that from watching afleetcommand on YT. Makes a lot of sense though.
