Could anyone solve this issue?

[Dinodi]

Hi All, I have Stihl BR700 old one. It won't start, so I replaced a new spark plug, carburetor, fuel filters, vent, fuel lines, and carburetor, but still not being running. I tried an another way, like this I sprayed some fuel, mix oil, into the carburetor and pull the coil handle then, running for a few seconds normally and stopped. I tried repeat and repeat but happened same situation. How can I solve for this case ? Can any one advise me of it? Thank you.

 

[Mastermind]

It just isn't getting fuel. Which could be an impulse issue. Have you removed the muffler to check the condition of the piston?

 

[Squareground3691]

Is it pulling fuel threw the primer bulb when you pump it . ?

 

[Stump Shot]

A fella on here not long ago had the same issue with his 4-mix Stihl verbatim.
Issue was solved with the carburetor being adjusted to let more fuel in.
Other issues could be at play, this is a good place to start the diagnosis.

 

[Mastermind]

My very first move on any older piece of ope is to pull the muffler. Might seem crazy.....but the amount of time I've saved in trying to make a fried piece of equipment run is huge.

 

[farminkarman]

My very first move on any older piece of ope is to pull the muffler. Might seem crazy.....but the amount of time I've saved in trying to make a fried piece of equipment run is huge.

Prolly best answer material right here.

 

[Stump Shot]

My very first move on any older piece of ope is to pull the muffler. Might seem crazy.....but the amount of time I've saved in trying to make a fried piece of equipment run is huge.

...and another quick go to is pop the fuel cap off and shine a flashlight to look at the fuel. If gin clear, or if it can't be seen through at all... there's your sign.
It's called diagnostics(plural) for a reason, through the process of elimination the fault can be found. Rather than go through all that some would just as soon skip ahead to the correct answer, which isn't the easiest when you have the problem right in hand, let alone over the internet. Some tricks like this however are always good at helping get to the proper answer sooner than later.

 

[Stump Shot]

Prolly best answer material right here.

Only takes a minute to do and when it's found out nothing is wrong going on the peace of mind going forward is worth a bunch.

As a side note when you're looking in there, take a blunt appropriate sized object and push on the rings to see if they are free even when they look good. Should be a little bit of spring to it while in the exhaust port.

 

[Dinodi]

Is it pulling fuel threw the primer bulb when you pump it . ?

yes, it does.

 

[stretch5881]

My very first move on any older piece of ope is to pull the muffler. Might seem crazy.....but the amount of time I've saved in trying to make a fried piece of equipment run is huge.

Not so crazy. I find myself checking compression first a lot. Then the screen.

 

[Dinodi]

It just isn't getting fuel. Which could be an impulse issue. Have you removed the muffler to check the condition of the piston?

Not yet, I will try it. Thanks.

 

[Stump Shot]

 

[Stump Shot]

Not yet, I will try it. Thanks.

Keep after it and do not get discouraged, you'll find it.

 

[chris421sd]

first test should always be a compression test not pulling the muffler, if the compression is below runout it will tell you if the engine is scored, if rings are worn, broken or weak, or if the cylinder is worn out pulling the muffler only tells you if it is scored. if it looks clean and is under compression runout then pulling the muffler tells you nothing and sends you around in circles on diagnostics which is why pulling the muffler is not a diagnostic step.

 

[Stump Shot]

While it's generally not taken literally speaking, usually something led ones self to pop the muffler off, for me it's usually I rolled the engine over both fast and slowly and something just doesn't feel right about it, it could be what the operator said about it, or what I found in the fuel tank. Add to this a quick look down the spark plug hole with a mini light, only takes a couple of seconds after the spark plug is removed. If I can see damage on the exhaust side cylinder, there's no sense dragging out a compression tester.
Then remove the muffler and see how bad the situation is best as can be before going any further. Then the decision, to repair or to junk is made after a $$$ evaluation is made.
Also I would point out that 95% of what comes across the bench for damaged P/C is a scoring event, broken and stuck rings are not quite common and sadly most of these machines get burned up before ever getting anywhere close to being worn out. So it's just a matter of playing the odds. And you will find those with severely damaged pistons still holding reasonably good compression, little more than a half inch at the top of the stroke will build enough to fire and run.
It's nothing that can be taken from a text book, rather from experience over time that brings a person to such conclusions. So can a compression tester help diagnose these things as well? Most certainly, alas just not the only way. As long as your way gets you to that proper conclusion then who's to say who's is right and who's is wrong.
Lastly, not everyone asking for advice has a full compliment of two stroke mechanics special tools, making them go out and get one might only not find the problem, but discourage the saw owner as well.
The hardest saw you'll ever fix or fail on is one you've never laid eyes on. I find it extremely difficult at times to nail it at the first go around, some times I am when everyone else is not and sometimes the reverse is quite true as well. That's just the way it goes and we don't get the benefit of any more clues that one would find along the way through the process either for the next guess, only what could be wrong can be brought forth. However, with the benefit of having many members present with all different experiences that right diagnosis is usually in there.

 

[Mastermind]

first test should always be a compression test not pulling the muffler, if the compression is below runout it will tell you if the engine is scored, if rings are worn, broken or weak, or if the cylinder is worn out pulling the muffler only tells you if it is scored. if it looks clean and is under compression runout then pulling the muffler tells you nothing and sends you around in circles on diagnostics which is why pulling the muffler is not a diagnostic step.

I'm just now getting started on this stuff. Everyone should disregard my opinions.

 

[farminkarman]

first test should always be a compression test not pulling the muffler, if the compression is below runout it will tell you if the engine is scored, if rings are worn, broken or weak, or if the cylinder is worn out pulling the muffler only tells you if it is scored. if it looks clean and is under compression runout then pulling the muffler tells you nothing and sends you around in circles on diagnostics which is why pulling the muffler is not a diagnostic step.

Ever wonder why people want to see piston pics instead of compression test readings when buying used saws?

 

[stretch5881]

I'm just now getting started on this stuff. Everyone should disregard my opinions.

Your opinions and experience are very important.....in my opinion.

 

[chris421sd]

the other thing many people miss about compression tests is it gives you a baseline to health of the enngine, i have seen so many 2 stroke engines with low compression that run but preform poorly, are hard to start, and lack operating power and no one can ever figure out why because the cylinder appears ok through the muffler and they dont bother testing compression and if they do they think dangling the saw by the pull cord tells you this information. i also cant count how many times the piston is clean on the exhaust side but scored on the intake side because the operator doesnt know how to clean the air filter in the engine and the intake gets "dusted" by debris and damages the intake side.

 

[chris421sd]

Ever wonder why people want to see piston pics instead of compression test readings when buying used saws?

i dont wonder i know why they want to see pics of a piston it is so they get a false sense of security of the saws condition because it only tells you one thing and i have customers who bought saws online this way and the guy just took pictures of a different piston and cylinder before he sent it to them just like someone can show false compression reading in a picture i have seen it too many times only worth pulling the muffler if you trust the guy or are standing beside the engine when the muffler gets pulled.