2 cycle engines driving me nuts

[ohiofarmer 3,164]

  I have an Echo weed eater bought new and a small Stihl and a big Dayton [Grainger -Poulan] saws that will not start.  I bought carb kits for the old tillotsons and not having a lot of luck.

  i tested them without carbs on them and the little german Stihl fired on carb spray. It finally fired this morning and ran very well on fuel mix, but will not restart. The big Poulan kicked over a bit but never really started. it's a 4 cubic inch beast with a 24 " bar. The echo string trimmer just has no one home,

   i was thinking about trying all new spark plugs on these things to start with as all of them are at least thirty years old. Its pretty tough to see how good the spark may be by grounding it out , so looking for suggestions on that one. They all have great compression, so am concentrating on fuel and spark. 

   Our Wheel Horse tractors are simple compared to this stuff. I can get by for a while with a Poulan pro for a while, but i have work to do and having more than one saw while cutting down a tree can be a good thing. If you guys have a good resource on youTube  that i can use to diagnose or just some hints, I am all ears.

[lynnmor 6,873]

Did you replace vacuum line if it has one?

Did you replace the fuel line?

Did you replace and adjust the pump diaphragm?

Did you check any rubber intake parts?

Are you using a fresh fuel mixture?

[Bill D 1,665]

Check the exhaust for blockages from carbon.

[JoeM 7,769]

there aint much to a 2 cycle carb. If you thinking that is good 

 I would move toward the spark end of things. I know the air gap of the mag is critical for easy starting . I like 10 thous. 

[squonk 39,223]

Crankcase has to seal so vacuum will draw fuel out of carb. Leaky crank seals =low vacuum.

Edited April 3 by squonk

[oliver2-44 8,947]

5 hours ago, squonk said:

Crankcase has to seal so vacuum will draw fuel out of carb. Leaky crank seals =low vacuum.

I have a Stihl 180 that runs good till it gets all warmed up.   Then it’s starving for fuel. The polycarbonate part of the crankcase then leaks at the case. You have to tear the saw completely down to replace that gasket. 

[ohiofarmer 3,164]

   I bought carb kits for all the carbs. the diaphram is epecially important. i am confused at how you would adjust such a thing.

  One thing I did right away was to remove the mufflers and examine the blockage and also look for scoring on the piston walls..

   My next move is fresh spark plugs and look for a way to test for spark.. A good many lawn and garden mechanics do not mess with string trimmers any more. I have one string trimmer that was given to me that would run except the engagement pawls are stripped out. It has a provision where a five sided drive pentagon rod would let me start it with a drill, so that's a possibility.

   I think my choice in two cycle might be echo or Shindawa because Stihl has gone to plastic internal engine parts in some cases.

   Gonna get some off road unleaded and use Red Armor for my fuel mix. I think that I am just gonna use a finely calibrated cup to mix a batch at a time from now on. Synthetic two cycle oil is getting pricey, so a gallon at a time makes no sense for the homeowner with a string trimmer. We still do have a DeWalt battery powered with a 5 amp hour for around the house, but I want my gasser working again

[lynnmor 6,873]

3 hours ago, ohiofarmer said:

   I bought carb kits for all the carbs. the diaphram is epecially important. i am confused at how you would adjust such a thing.

 

Here is a video about the adjustment.  Yes, the guy is long winded.  Look up the specifications for your particular carburetors.

[pfrederi 17,200]

I have the $5 harbor freight spark tester but sometimes it will flash but no start.  It isn't very sensitive.  This B&S tester will tell you if the spark is strong enough.  There are oregon and other knock offs cheaper...but I have one of those and  don't think it does as well...

 

 

[oldlineman 1,453]

Might be late, but use corn free gas at all times in small 2 cycle and for that matter larger 4 cycle engines. That is all I will put in my stuff and have no problems. Bob

[BESTDOGEVER 218]

Try new spark plugs, preferably bosch or ngk set at. 020, use at least mid grade gas and the best mix oil you can get. Check for grounded out kill wires. If that doesn't work and the coils/modules show spark you are probably looking at crank seals which are pretty much a death sentence for 2 cycles. If this and the previous thoughts don't get some results it's not a hopeful sign. 

[wallfish 16,071]

8 hours ago, BESTDOGEVER said:

you are probably looking at crank seals which are pretty much a death sentence for 2 cycles

Old school brake fluid (Not synthetic) can be used to soften and swell the seals if new replacement seals aren't available. Of coarse, replacing them is the best option, 2nd is to carefully remove them and soak in brake fluid, 3rd is to just do them in place. Just a few drops down in there and let them sit for a day or 2. It won't work if they're dried and cracked but most common is stiff and worn. The softening and especially the swelling can make a huge difference. 

Brake fluid also does wonders on old tires.

Unfortunately just like everything else, the newer stuff doesn't work near as good as the older stuff did. The stuff sold for sealing oil or trans fluid leaks can work too as it's basically the same idea.

[peter lena 8,144]

@ohiofarmer  as with anything  mechanically old , have see amazing , lubrication based , cleaning / function , after adding  KROIL  OIL  to the lube /  fuel , have run in a number of long dead engines , with heavily treated fuel , just an idea , wake things up easily Pete 

[wallfish 16,071]

34 minutes ago, peter lena said:

@ohiofarmer  as with anything  mechanically old , have see amazing , lubrication based , cleaning / function , after adding  KROIL  OIL  to the lube /  fuel , have run in a number of long dead engines , with heavily treated fuel , just an idea , wake things up easily Pete 

You actually run KROIL OIL in the fuel of 2 stroke engines?  Instead of 2 stroke oil or along with it? Interesting

Heavily treated fuel for a 2 stroke might foul the plug and or not burn off completely leaving deposits in the chamber or the exhaust so I wouldn't run them for a long time like that. Plus plenty of smoke too. Not sure how hazardous the burning vapors for that stuff can be either. The exhaust is typically directed away from the user for string trimmers and saws but the majority of little 2 stroke powered tools I have it isn't. But still you shouldn't be standing there breathing the exhaust vapors either!

Could running that stuff actually wash out any or all of the regular 2 stroke oil lube by what's leftover after burning it? Like it's too thin. Or possibly leave a sticky substance? I've never tried it and probably never will. Maybe it works but I'd stick with running it in short bursts unless you know for sure. 

 

I do run 2 strokes a little heavy on the oil side for a 1/3 - 1/2 tank with the proper oil on an unknown engine that has sat for a long time, just to supply some extra lube while it washes anything out. because old 2 stroke oil will gum after the gas evaporates. 

And a side note, Use specifically designed air cooled 2 stroke oil on air cooled engines too, marine or outboard oil is a different formula and many engine manufacturers will state not to use it.

[OutdoorEnvy 1,479]

Yeah cheap 2cycle stuff is garbage most of the time.  They just aren't worth the effort and parts cost in most cases.  I used to do small engine repair as a side gig for a few years and hit the point of I wouldn't work on the cheap stuff.  Stihl, Echo/Shindewa were the only brands that seemed to want to run.  Even Husqvarna would be nothing but issues.  Just not worth it to pay someone to fix these.  If you are trying to save one yourself then a carb and tune up kit isn't terrible but the coil, etc. get to be costly in some cases. 

 

As for tips to keep trying I think for sure getting a spark tester and compression tester is worth the investment.  These don't cost much and will be handy for anything.  Sometimes the loss of spark is from a dirty flywheel with either debris or rust over the magnet spots.  If you find you have spark and compression then you might try the breather tube and end point.  These clog but you usually have a condition where it starts and runs for a second or so and then dies out.  Also fuel lines get cracks and leak and cause issues with fuel delivery that aren't always noticeable offhand.  Sometimes the ignition switch goes bad or the wires to it get broke or frayed and cause no start/spark issues as well. 

[Lee1977 6,310]

I have used carb. cleaner to wash down the exterier of 2 cycle engines. would notice fire at the frist pull anmd nothing later,. Fire was grounding in the oily dirt.

I have an old SRM 1501 that the crank shaft seal is bad It's leaking gas and oil  out the crank shaft side.

Edited April 9 by Lee1977

[ohiofarmer 3,164]

I appreciate al the replies and have learned some new things.  Here is what I have done about the chain saws. I found two very well taken care of Echo saws with the old magnesium bodies.. A 450 and 650 saw that each start on the first pull. They look like a million bucks with very nice paint. The guy who sold them had them listed separately on marketplace. I asked him for a package deal and he sold them both for less than the ask on the big saw.  He is starting a new business that is only four months old and still continues his work as a Diesel mechanic. Sharpens chains for five and builds big twenty inch chains for less than fifteen. i predict that he will have to raise those prices some or he will never have a moment's peace.

   I have a Stihl Farm boss and consider the Echo saws to be superior to it  in many ways.  That Fam Boss  saw was nice until a friend borrowed it , so maybe i will fix it when I have time. I took the little 020aV Stihl for the shop to evaluate on a return trip. The Echo string trimmer i have works probably just by pumping fuel through the bulb many times after i rebuilt the carb.

   BTW, I had no intention of letting my friend use my chain saw . I went to help him at his campsite by bringing my saw for MY use, but when i went to town to pick up mower gas, he used it to cut plywood and smoked the chain . Of course the chain got hot and then loose. He lost one of the bar nuts and horsed the other one down so tight that the stud got stripped and it pulled out partially. I am glad I never said much, but all I tell him if he needs a saw is that the stihl is down with bar problems. When I was hospitalized for seven weeks last year, he built a hand rail so I could get in and out of the house, so it all evens out....

   Thanks again, guys i will take some piccs of the echo saws with the other camera. For some reason the forum does not recognize my cell phone camera

 

[Handy Don 10,789]

On 4/12/2024 at 12:18 AM, ohiofarmer said:

That Fam Boss  saw was nice until a friend borrowed it

Things that I don’t lend--chainsaw, chipper/shredder, and the 854, When I want to be helpful, I go with the tool and operate it.

 

[Terry M-(Moderator) 2,128]

1 hour ago, Handy Don said:

Things that I don’t lend--chainsaw, chipper/shredder, and the 854, When I want to be helpful, I go with the tool and operate it.

 

Very wise choice..👍

[ohiofarmer 3,164]

that

On 4/13/2024 at 3:56 PM, Handy Don said:

Things that I don’t lend--chainsaw, chipper/shredder, and the 854, When I want to be helpful, I go with the tool and operate it.

 

    that was my exact intention. I told him I would operate my own saw. i had no idea that he would grab it while i went to pick up gas for him..  After that fiasco, a couple of years later, he put diesel in the hydraulic tank of his brothers bobcat..... And he used to own a bobcat himself

[Handy Don 10,789]

5 hours ago, ohiofarmer said:

that

    that was my exact intention. I told him I would operate my own saw. i had no idea that he would grab it while i went to pick up gas for him..  After that fiasco, a couple of years later, he put diesel in the hydraulic tank of his brothers bobcat..... And he used to own a bobcat himself

Sounds like someone neediing adult supervision when neear machinery

[lynnmor 6,873]

5 hours ago, Handy Don said:

Sounds like someone neediing adult supervision when neear machinery

 

Folks like that need to rent a second floor apartment next to public transportation, but that may be a considerable portion of the current population.  I have stayed away from social media till just recently when I had some use for it, the idiocy is astounding.

[ohiofarmer 3,164]

On 4/15/2024 at 7:42 PM, lynnmor said:

 

Folks like that need to rent a second floor apartment next to public transportation, but that may be a considerable portion of the current population.  I have stayed away from social media till just recently when I had some use for it, the idiocy is astounding.

    

      Now about his good qualities. Back in the construction recession of the early eighties, I decided to fill a construction teaching position at a vocational school  So here I was at 35 and he at seventeen. His father predicted failure at school, but he was the hardest working student there. He has come a long way with his life and was able to retire early [ and maybe just in time} as a real estate developer around Gatlinburg. He taught me a lot about the pain a non loving family can cause. in any case, i helped him build a very unique cabin twenty years later that is rented in every season to almost full capacity.

     You know the type of people who are always driven. so hard by impatience. i see it as trying too hard to prove himself to his dad. So normally i would be pretty unforgiving , but in this case, I looked at the friendship we have as not worth risking over a chain saw. i had to bite my tongue a few times for the same kind of stuff when my daughter was out too late and she lost her college car to a drunk driver. . I took a bath with the insurance company over that one and my wife kept me from saying much about it. So sort of the same thing.

   When I was very ill after back surgery, he came up from Tennessee to build a handrail so i could get into the house. would not take a dime, so him fixing that saw is a moot point.

     I finally got a chance to run the Echo 40cc and that thing just eats. The 65cc Echo is really for the big stuff and firewood. Both saws start and run on the first pull.so the farm boss Stihl is not needed this year. pretty sure it is a  028 sized Stihl. Anyway, all the 2 cycle stuff i really needed this year is up and running fine. Never will I ever lend another power tool to anyone