Shindaiwa 757 owners, need some help please.

[k9trainer]

First off, I absolutely despise having my first post a cry for help, so please excuse me for that. I've been searching for info for hours on end to my problem with no avail, just not enough 757 threads and owners out there I guess.

Ok, here's the low down. Saw was basically brand new when I inherited it from my Gramps about 5 years ago. I have used it extensively with zero issues ever, the saw has just plain ran perfectly every time out. Run non-ethenol gas and some bottles of the premix VP 94 fuel now and then. Keep filter clean and even clean the saw after every use. Plug is perfect every time I check. About a month ago I get the saw out and am cutting a log when I hear a few quick misses. Then all of a sudden the saw starts to bog, struggles to stay running, and eventually dies. It does start back up after a few pulls, but continues to run rough, won't stay up in rpms, and again dies.

Getting the saw out cold it starts fine and runs perfect for the first 6-7min, then does the same thing. This has happened 8-10 times since the problem started.

Took carb off, cleaned it, same thing.

New plug, same results. Put a new air filter in it, no help.

Took it into an Echo dealer that services Shindaiwa and had a horrible experience. They took the muffler off and when they tried to reinstall it they partially stripped the two threads around the exhaust port. They claimed the threads were already stripped and wouldn't touch the saw, but sure offered to replace the cylinder for $350 for me....grrrrr. So I have the saw back, fixed the threads, muffler is solid. Took it out twice and issue repeats the same as before.

Thoughts? Any help is greatly appreciated. This saw has such sentimental value to me being my Grandfathers and want to get it fixed properly.

Also, anyone in the midwest do work on these saws to get more out of them?

 

[Warped5]

My thoughts are (1) muffler screen is clogged or (2) coil is failing.

'Four Paws' and 'Alderman' are the Shinny experts around here.

 

[pioneerguy600]

Check your fuel tank vent first, the engine could be starving for fuel if air cannot get back into the fuel tank to replace the fuel that has been used up.

 

[Guido Salvage]

In addition to what Ted says, also check your fuel lines and filter. A collapsing or split fuel line will also cause inconsistent running.

 

[Four Paws]

Kit the carb.
Install a new fuel line and filter.
Try saw again.
if it repeats, crack the fuel cap to equalize pressure.
Try saw again.
If it repeats, pony up for a coil.

 

[Brian Carlson]

Don't feel bad for your post being in the help catagory. I did the same and theseguys were great. That's how we all learn about these awesome machines. I have a 757 and I love it. I agree with the previous posted suggestions. It's got to be something minor. I put my money on the coil. Good luck and get that puppy going.

 

[Guido Salvage]

Fez or low top?

 

[Brian Carlson]

I traded for the saw and it came with factory air cleaner. I found the hd filter setup and haven't gotten to cut with it yet. I have to find another fuel tank/handle cause it leaks down the seam in the middle. I might just try and plastic weld the seam unless I can dig up another handle.

 

[k9trainer]

Thanks so much for the ideas, I will certainly dig into her tomorrow. What do you mean "fez or low top"

 

[Guido Salvage]

Both of mine have the "fez" or high top air filter.

 

[alderman]

Thanks so much for the ideas, I will certainly dig into her tomorrow. What do you mean "fez or low top"

The HD filter cover looks like a Shriner's fez hat. Looks especially pronounced on the 488 and 577. Just something you have to deal with when running Shindaiwa.
I've got a couple of 757‘s. The newest one was bought used with just a short amount of run time on it and did die in the cut once and was hard to restart. I haven't run it enough to know if the problem will show itself again. It could be a coil issue but there are some cheap things to check first as stated above.
Four Paws is the real go to guy on these saws as all I do is buy them, do fuel lines and carb kits and run them. Not much of a mechanic.

 

[bigwhiteash]

K9, if you try all the fuel related stuff and it still doesn't go, I could send you a known good coil from my 757, you could try it and ship it back, but that might be more than the cost of a coil, dunno.
Kyle at Edge and Engine may have the parts and some insight into your saw.
JinNJ

 

[k9trainer]

Thanks for the replies. I took the fuel tank vent hose off, soaked it overnight, and blew it out with compressor. The saw ran good when I first got it out, with 1/2 tank of fuel down to near empty. Once I filled it back up it started to run poorly again. During a cut it wouldn't get up into the rpms like it should, and did with less fuel. I took a video of it struggling to come off idle a bit.

 

[k9trainer]

Well the saw didn't even start the last time out. I ordered new fuel line/filter, vent tube, so crossing my fingers that might help. I'm still getting spark, does that rule out the coil?

 

[Brian Carlson]

Might try a carb kit too. Might have a torn diaphragm.

 

[Ambull]

Sounds like it is starving for fuel, because it has no torque and then runs away once it builds up speed. Rebuild the carb. Make sure that it is getting a good impulse for the pump. Can't remember if there is an impulse line on that saw, but if there is, most likely it is either cracked or clogged.

 

[fearofpavement]

An offbeat but feasible cause, make sure you don't have debris in the fuel tank that is plugging up the filter. ie, dump out the tank into a peanut jar and let it settle a bit. If it's good and clear, put it back in after inspecting the interior of the tank.
Earlier you said the saw ran better with a partially full tank than a full one, that would point to a venting issue.

 

[bag-o-donuts]

+1 for vent/breather issue...

 

[Miles86]

Howdy-

Nice saw, I would avoid the dealer that messed up the cylinder threads, makes me mad.
Did you check the spark screen in the muffler? Fuel line cracks can be hard to find, I had a brushcutter with a bad line and I only found it by flexing the line under a magnifying glass. Check the flywheel and coil air gap, maybe a failing coil? Grime buildup on the flywheel? Change the spark plug? See other posters advise to install a carb kit after a good cleaning of the carb.

Last resort do a pressure / vac test due to the age and lack of regular use, stiff seals etc...

 

[peter92]

Will be watching this with interest as ive just bort one, and know i have to change a few things
Peter