Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Stihl => Topic started by: SWPA TreeGuy on August 02, 2012, 07:33:04 pm

Title: 064 help please!
Post by: SWPA TreeGuy on August 02, 2012, 07:33:04 pm
im new here so i hope this posts. first off ive been  in the tree business for 21 years and own my own business for 8 years now and  i have NEVER seen this problem. ok i have an 064 just bought it few months ago, vgood cond. i just put a new coil on it and got it running. im  cutting a big pine log today and half way through the saw slows down like its getting jammed  then comes to a stop(the chain stops NOT the engine). next thing i know the saw is trying to kick back like its running backward and im thinking no way? i pull it out of the log and rev it up full throttle and i cant beleive it but its running backward. thats right the chain is actually spinning backward then when i let off for a bit and wait and restart it its back to normal. then i run it a while longer and same thing. i have no idea whats wrong im guessing a few things? did it jump time and the crank is spinning the wrong way? or when i put the coil on the say could it be too close to the flywheel? i used a business card so im guessing its gapped about .010. if anyone can help i really appreciate the help. thanks
Title: Re: 064 help please!
Post by: Cut4fun . on August 02, 2012, 07:41:14 pm
Welcome to the site.

I have only heard of this about half dozen times now and sorry I am no help as to why it's happening. I would like to know why also though. 

Hopefully  some of the others have experience with this.

Title: Re: 064 help please!
Post by: man of stihl on August 02, 2012, 08:10:58 pm
Sounds like a timing issue. Look at the flywheel to make sure the crank and flywheel is alligned. Might have sheered the key/keyway? Are you sure you have the right coil on that saw? They made so many coil\flywheel changes to that series.
Title: Re: 064 help please!
Post by: SWPA TreeGuy on August 02, 2012, 08:20:33 pm
im sure its the right coil i replaced it with the exact number right off the coil and they look identical and  bolted up identical. im pretty sure that was the original coil on the saw it had 2 bolts in it and i see a 3rd hole on the saw and see there are a few different coils that would fit it but i kept the same 1 so im pretty sure thats not my problem. now when u say look at the crank and flywheel and make sure they are alligned, i may have a problem there because i dont know exactly what im loloking for there. just to let you know i never touched the flywheel, never had it off or anything but u are saying maybe it jumped time? if so whats the fix?  i am not running it now because i dont want to tear up the cyliner/piston or  crank . i know the piston can only go up and down but seems to me the crank has to be turning the opposite direction? im no mechanic just looking for any help. thanks guys for your input i appreciate it
Title: Re: 064 help please!
Post by: Cut4fun on August 02, 2012, 08:31:36 pm
Some old 064 066 info I remember reading.

Just 2nd hand info and dont know how accurate it is.

There is a lot of confusion over the 066 'red eye' or 'red light' model saws. Also a lot of confused between the Red Light 066 and the similar limited non red light 064. Even in what has been posted here. You can run an early model 066 red light with the aluminum flywheel with one of the later aluminum flywheel unlimited coils. All the US 066 AL flywheel models should only have one key in the flywheel. I had an AL flywheel on my Red Light 066, and I still have the later Iida coil model from it. It ran fine. The limited coils were commonly pulled and replaced with unlimited ones to run better. This was because the red light coil module would fade out over time and limit downward on RPM's (like 12.5k down to 10k RPM). The non-limiting coils do not have the extra wire and LED lead though. Some 066 red lights were Magnums (mine was), meaning they had the dual port muffler for increasing the 7.3 HP 'regular' 066 to 7.8 HP.

I have the Stihl 066/064 factory ignition module tech sheet that lists the 6 most common aluminum and poly flywheels (there are a whole series of them) as well as all the matched coils. However, there were 9 options in all. There were at least two later models of AL flywheels on non-red-eye 066 before they flipped to polymer in 1996. The red light 066 was only made for a short period of time. They were only made on a very early flat top 066; there was no later model 066 using them. There was an RPM rev limiter in the coil and an LED lead running from the coil to an LED light at the side of the saw. The light lit up when the rev limit was reached and the coil was cutting out. This was so that you could tune the carb H screw to lean it out just until it was cutting out, and the LED light was flashing. For that reason these saws had engines that were fairly bullet-proof; it was nearly impossible to score the engine with the limiter in them. Only straight gassing did them in. Or the bearings went out, as was the case with mine. The swapped out red light and later models of 066 with the AL flywheel and unlimited coil had a common problem with spinning the flywheel side of the crankshaft off because of over revving. So Stihl made the flywheel side of the crank thicker in 1996 and replaced the aluminum with a poly flywheel. They also changed the ignition modules to to advance the timing at high revs on the later poly coils. The AL flywheel coils are straight-line timed ignitions; they do not have an advance curve in them like the poly modules do. The CDIC coils also had a timing retard in them at low speed for easier starting.

In the above post, the 1303 module was in the 064, and not the 066. The red light 066 coil module was a Prufrex CDIC, Stihl PN: 1122 400 1307 (similar to the 064 module, but it has the LED lead). It was changed to an Iida unlimited coil module, Stihl PN: 0000 400 1300, in 1993 and retained the AL flywheel. That was changed to an Iida unlimited coil module, Stihl PN: 1122 400 1311, in 1994. The 0000 400 1300 coil is a generic coil and is still used in some of the new larger Stihl saws. The 064 also had a CDIC coil put in them from 1989, but there was no red light limiter LED. Note that only the 064 AL flywheels have two key slots. This is to accomodate different types of ignition; one was for electronic ignition, and the other was for analog points and condenser ignitions. On these flywheels, B stands for Bosche (old points) and P stands for Prufrex (new electronic).
Title: Re: 064 help please!
Post by: man of stihl on August 02, 2012, 08:40:13 pm
The key lines up the flywheel and crank. Here is a pic of the keyway in the flywheel. I would take a look at this first then we can go from there. You can also give me the numbers off the coil and flywheel and we can see if they match. just to rule that out too...
Title: Re: 064 help please!
Post by: Al Smith on August 02, 2012, 09:36:45 pm
I don't know if this applies or not .However certain Stihl models used self advancing ignition moduals .

Now I have no idea how it could happen or even if it's possible but it theoretically reversed the spark .If it did though it would have to have came to a complete stop then start up again in reverse .The compression could have at least in theory kicked it over backwards enough to restart .

Way back when they used to get kart engines running backwards .Rather comical to watch .

I've had the SEM coils go bad where they would not advance which causes them to run at about 1/3 speed .Conversely I've had Briggs and Stratton coils stick on full advance making them impossible to start. Also makes the magic smoke go out of the little starter motors .
Title: Re: 064 help please!
Post by: ngk on August 03, 2012, 07:52:29 pm
Some of the old 266 and 630 would run backward the key on the fly wheel was cut in the wrong spot new fly wheel and the problen solved.
Title: Re: 064 help please!
Post by: pete on August 04, 2012, 07:14:32 am
Red Neck fix what would happen if you put the chain on backwards
Title: Re: 064 help please!
Post by: joe_indi on August 04, 2012, 10:51:45 pm
If its running backwards with the chain running (that is with the clutch engaged) wouldn't the clutch come off the shaft?