Restart trouble with 064

Burnham

Woods walker
Joined
Mar 7, 2005
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22,932
Location
Western Oregon
Wednesday afternoon my wife and I cut a load of firewood, using my fine old Stihl 064, bucking 40 in. Doug fir. For the first time since I acquired the saw a few years ago I had some trouble from it.

Starting cold first thing, no problem...full choke, 3-4 pulls 'til she popped, go to half choke, one more pull and away we go. The saw ran fine, pulling 32" bar fully buried with no issues. Idled fine, no hesitation anywhere in the power band. Ran it about 30 minutes, I guess.

I then shut it down for about 45 minutes while we split and hauled some wood out to the truck. In my experience, this saw would not need choke to restart at that point...so I gave it a few pulls and got nada. Eventually, lots of pulls later, it finally popped a bit, but it took another 6-8 pulls before it would run long enough to get on the throttle and goose it up to speed.

After that, ran great, idled fine. I cut for another 20 minutes or so, with no issues. That made the load, so I didn't have to start it again...but when I got home a couple of hours later it did the same darn thing.

I haven't had time yet to delve into it, hope to this weekend...but with such a fine gathering of saw gurus here I thought I'd see what y'all might suggest I look at first for possible causes.

Here's a pic from another firewooding day, just 'cause I think this saw looks so good!
 

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Check valves are getting stiff in the carb .It's a warning,rebuild the carb .

What happens is the flapper type check valves become a tad stiff which allows the tiny bit of gas in the diaphragm chamber to drain back into the tank .Can't start with no fuel in the carb .

You never know how long they will last, maybe a few years maybe longer .I just recently had to rebuild the carb on my little S-25 Poulan that I bought in the mid 70's .Surprised me it lasted that long .Same deal ,ran fine then kind of died on the vine all the sudden .
 
YUP! With two hours sitting it's past a tank vent plugged up, it's carb time! Might be worth the effort to change the fuel and impulse lines while you are in there rebuilding the carb.
 
Might be less work to just use the choke if it is running fine.;)

Personally I have never had a saw new or old that would start with out the choke after sitting for more than 20 minutes. Even sooner in the winter at -0F temps.
 
It depends on the saw I suppose .The super duper 038 Mag takes about ten on a cold start but once that thing has fired it's good to go all day usually on one unless it's sat long enough to cool then it's one with the choke .

Now I've got a souped 70 cc Mac with an over sized carb off of I think a 125 .It will start on 3 or 4 and restart on one no matter how cold it is unless it sets for an hour . You'd think with that big carb it would flood but it doesn't .
 
I think carb too, renew the diaphragms and put in a new metering needle. The metering lever height is probably ok, but at least check, and make sure the plug and ignition gap are kosher for the next twenty thousand miles..
 
A carb rebuild would be the most logical and cheapest fix if the problem is with the carb.

I had a expensive go round with my 64 about 6weeks ago that I would like to share because I didn't really think it was worthy of a new thread. Burnham is the only one here that I know that has a 64.

I also bought my 64 used many years ago and it has been a good saw . I just wished it had a decomp valve in it to make starting a little easier because it has a ton of compression. My 64 was also getting finicky and harder to start than it should but ran fine once it got going. This summer it was getting to be a real pain to start and finally it wouldn't start at all. The ignition module was getting weaker and finally died because of no spark.

The older original style ignition module for a 64 are no longer available. The module for the 066 will work and that is what came when I ordered one. The problem didn't end here. I also rebuild carb and had spark again but the saw had so much compression it was really hard to pull the engine over almost impossible to be truthful without putting some real arm strength on the recoil rope and literally standing on the saw. It tried to fire but couldn't because the timing was now off a few degrees. It did start once but ran really weird because it was firing early. I called the dealer to tell them of the problem but they thought I didn't know what I was talking about and told me I installed the module wrong . This kind of teeed me off so I brought the saw into them. Guess what the tech said. It was firing early.:|::|:

What do we do now. We call the super tech at the distributor to find out what to do. To solve this problem we have to get a new flywheel with two slots machined into it. One for the old ignition and one for the 66 timing. The 66 flywheel won't work.

Along with a new 30 bar, chain and sprocket and the new ignition parts I dropped over $300 into a used saw but I felt it was worth it because the saw is stilll in very good condition with plenty of compression and no air leaks. Now the saw is running and starting and cutting like it should with no problems . Considering what it would cost to replace it with something of equal cc's I don't think I made a bad decision to fix it even the whole process took over a month because every part was on back order:X:X. It was better than parting the saw out. Not to many 64 's in our neck of the woods.
 
I wouldn't want to calculate all my time spent as equals expense in trying to figure out what was the problem with saws. The eventual repair seems to pretty much cancel it out, but there must be illogic to it.
 
Those people must have lost their marbles to make a high compression saw like that and no decomp but so was Husqvarna during that time .Geeze now they decomp 3 cubers .Go figure .
 
My Stihl 076 came with no decomp. I think around 111 ccs. It can be a kickback mofu too.

Just got to keep it in perspective.

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Nice saw, Burnham. Hope you get 'er fixed.

I've been eyeballing one to buy. It needs a wrap handle though.
 
Hot start. Old saws had other types of throttle lock, but newer is usually set with choke lever. Up with choke and down again so choke is open and throttle is locked in start position. If nothing happens after 2-3 pulls, full throttle start. Sometimes it flood when stopped or sitting if valves are not ok.
If it does not start and run on that something is wrong.
 
I have a 064 too, with a 066 top and coil. It was a real pain to start when I got it (very used). My first big saw. I had a hard time to figure what was wrong and it nearly killed my hand with kick backs. Early timing, as the 066 coil isn't the same as the 064 one, the mounting screws on the crank case aren't at the same place. The flywheel from 066 doesn't match, so I kept the 064 one. I widened the mounting slots on the coil, it was better but not enough. It ended by taking out the key on the axle and shifting the flywheel by the amount of an half key's thickness, maybe around 5° in the timing. Works well now.
 
When this subject first arose I was going to suggest an off set key .

In theory the coil should fire when the magnets align perfectly with the lamenations of the coil which should be the maximum high end of the voltage spectrum .

I can't make reference to either an 064 coil or an 066 to actually know if they have a built in advance on the timing or if in fact they are strictly set at one point .
 
When this subject first arose I was going to suggest an off set key .

In theory the coil should fire when the magnets align perfectly with the lamenations of the coil which should be the maximum high end of the voltage spectrum .

I can't make reference to either an 064 coil or an 066 to actually know if they have a built in advance on the timing or if in fact they are strictly set at one point .

They have active timing and I thing alu woodruff key If I remember correct.
 
A key really isn't that hard to make .You just get the appropriate size of round stock ,cut off a segment and finish it with a file .Rather tedious but still simple .
 
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