Jump to content

Log in or register to remove this advert

Recommended Posts

Posted
Cranked the saw over, no fuel coming from the fuel line to the carb, tank doesnt appear to be pressurizing! noticed two deep scores parallel to one another below the piston ring, would this affect it in any way?

 

 

You say good compression, how did you test it?

 

You say the jets are OK but you also say dry carb, have you seen the jets work

 

Time to take the barrel off and have a look

 

If its scored bad that means less compression, which means no pressure diferential and that means the impulse wont work which in turn means no fuel.

 

Either way badly scored means the fuel is a moot point.

Log in or register to remove this advert

  • Replies 26
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Posted Images

Posted

If you have significant scoring you may not generate the impulses needed to operate the fuel pump, so you need to do a comression test.

 

If you have sufficient impulse but dont pull fuel, then your impulse line may be fractured, or the fuel pump daphragm could be hard or split . If these are ok and its not pulling fuel then it could be blocked gauze or split pickup hose ( everything Spud says)

 

You need to do some tests and diagnosis.

 

Edit, sorry to the last two posters, I am a slow typer!

Posted

The carb is dry but the saw will run with fuel put down it. That means that there is enough compression for ignition, the dry carb means that the impulse circuit is not pulling fuel up from the tank.

 

The pumping of fuel from the tank is done by the pressure and vacuum in the crankcase - this carries on working even with poor compression - it is the lack of compression that stops the fuel being drawn from the carb in to the engine - be clear on that - it is important.

 

Long and short - if the carb hasn't got fuel in the pumping section then it is an impulse problem, if there is fuel in the pumping section but NOT the diaphragm metering part then it is a metering arm problem.

 

The scores - if the scores are not in the cylinder above the exhaust port and the scores DON'T go through the rings then you will make compression - maybe not as good as a decent piston but probably enough for ignition.

 

Get a pic up of the piston - it isn't your problem from what you have described so far but worth a look at - a deep score to you may be a bit of carbon damage to anyone else:thumbup:

Posted
If you have significant scoring you may not generate the impulses needed to operate the fuel pump, so you need to do a comression test.

 

If you have sufficient impulse but dont pull fuel, then your impulse line may be fractured, or the fuel pump daphragm could be hard or split . If these are ok and its not pulling fuel then it could be blocked gauze or split pickup hose ( everything Spud says)

 

You need to do some tests and diagnosis.

 

Edit, sorry to the last two posters, I am a slow typer!

 

Too many cooks around here:lol::lol::001_tt2:.......and not a cake in sight:lol:

Posted
Too many cooks around here:lol::lol::001_tt2:.......and not a cake in sight:lol:

Sometimes I use the desk top and the ipad together, so I can check on posts others have made while I've been composing my reply. Then I can edit or delete before submitting. Less likely to look stupid!

 

Tonight however, only the ipad.:thumbdown:

Posted
Sometimes I use the desk top and the ipad together, so I can check on posts others have made while I've been composing my reply. Then I can edit or delete before submitting. Lessliely to look stupid!

 

Tonight however, only the ipad.:thumbdown:

 

You got a white cat you stroke and a bent on world wide domination ....Barrie Blofeld.....got a ring to it:lol:

Posted
You got a white cat you stroke and a bent on world wide domination ....Barrie Blofeld.....got a ring to it:lol:

Hhaha, that was quick, you made that reply before I corrected my spelling:biggrin:

 

Pussy stroking, hmmmm..... Think its my bed time!!!!

Posted
Too many cooks around here:lol::lol::001_tt2:.......and not a cake in sight:lol:

 

Fine. Here is one I made for the step fathers b day a short while ago.

 

I did make a stihl 200t cake aswell last year. Should really get the baking trays out more regular.

image.jpg.5748370fce10a2ba45f0b0cc6f91f5a2.jpg

Posted
You got a white cat you stroke and a bent on world wide domination ....Barrie Blofeld.....got a ring to it:lol:

 

Converting everything to aspen isn't exactly domination, oh and nice cake rich, unfortunately I fancy a steak instead now!

 

If the carb isn't getting fuel would it not be a filter or fuel valve problem? Has the saw been stored dry for a while? If it has, you might need to suck the fuel through the fuel line to get it into the carb, had to do that with a 357! After that it ran fine

 

 

Sent using Arbtalk Mobile App

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  •  

About

Arbtalk.co.uk is a hub for the arboriculture industry in the UK.  
If you're just starting out and you need business, equipment, tech or training support you're in the right place.  If you've done it, made it, got a van load of oily t-shirts and have decided to give something back by sharing your knowledge or wisdom,  then you're welcome too.
If you would like to contribute to making this industry more effective and safe then welcome.
Just like a living tree, it'll always be a work in progress.
Please have a look around, sign up, share and contribute the best you have.

See you inside.

The Arbtalk Team

Follow us

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.