Which way around

[BobL]

I'm in the process of replacing a disintegrated fuel primer bulb on my BILs Eager Beaver and my question is.
Which primer pipe stub (long or short) connects to the carby?
I pulled the primer bulb out of the case ( hoses had disintegrated) and then realised that I had not taken notice of this.

Thanks

 

[Woodslasher]

I'm in the process of replacing a disintegrated fuel primer bulb on my BILs Eager Beaver and my question is.
Which primer pipe stub (long or short) connects to the carby?
I pulled the primer bulb out of the case ( hoses had disintegrated) and then realised that I had not taken notice of this.

Thanks

Stick a finger over one of the end of one of the stubs and push the bulb, if the bulb won't refill that's the one that goes into the line from the tank.

 

[cookies]

the primer pulls fuel through the carb and returns it to the tank

 

[BobL]

All good thanks

 

[Old2stroke]

Usually the short nipple is the suck one that goes to the carb, but to test, just hook a fuel line to it and see if it will pump from a container of fuel.

 

[BobL]

Thank everyone I got the bulb sorted.
The saw had a few problems.
It was filthy as and every hose had disintegrated and had to be replaced.
Cleaned the air filter, and and spark arrestor which was badly clogged.
The remaining fuel was syrup so that was cleaned out with fresh fuel.
I also cleaned out the carby although that did not look too bad and the gaskets etc looked OK
At this point it would start (sometimes) but only run for about 10s but would not get to full speed and then stop
At this point I found Spark was intermittent so I removed /cleaned/inspected the coil (which was filthy) so now it has good spark but won't start at all.

Any ideas?
Carby kit?

 

[cookies]

did you gap the coil to the flywheel correctly? did you clean the flywheel magnets? I'd throw a new plug in it then see if it fires then try a squirt of fuel and see if it fires. If its a fuel problem again I'd suggest a new carb or check your reassembly job

 

[Backstage]

Always take pics as you go along.

So good spark. That means it’s fuel, air, or mechanicals.

You said you cleaned the carb. Both sides, got everything out of that screen? Checked the needle seats nice? Lever correct height? You also said you did some fuel line replacement. Possible anything’s still cracked/clogged? Checked the tank valve? Filter?

Pulled muffler and inspected piston?

 

[BobL]

did you gap the coil to the flywheel correctly? did you clean the flywheel magnets? I'd throw a new plug in it then see if it fires then try a squirt of fuel and see if it fires. If its a fuel problem again I'd suggest a new carb or check your reassembly job

Thanks Cookies
Flywheel magnets are clean
I dont have a manual for this saw so I don't know the required gap so I gapped the coil/fly wheel using the two pieces of printer paper method (80 thou')
The primary coil tests out at ~5 Ω sale the secondary is ~870 Ω
Out of the plug hole the plug sparks looks reasonable to me.

I also tried some ether based engine starter but not even a hint of start.

 

[BobL]

Always take pics as you go along.

I usually do but it wouldn't have helped as the old fuel lines had completely disintegrated. I learned this morning that the saw hasn't been used for 20 +years.

So good spark. That means it’s fuel, air, or mechanicals.

Yeah - spark now looks fine. But I am surprised its not even firing with a spot of fuel down the carby.

You said you cleaned the carb. Both sides, got everything out of that screen? Checked the needle seats nice? Lever correct height?

Yes, yes and yes, but I will do it all again.
I'm going to ultrasonically clean everything

You also said you did some fuel line replacement. Possible anything’s still cracked/clogged? Checked the tank valve? Filter?

Fuel Fliter is new, Dont know where tank valve is - the ones I've seen have been in the cap but I cant see anything special there on this saw

Pulled muffler and inspected piston?

Yep - Piston looks OK

 

[Thommo]

Has it got the vacuum operated oil pump that always fails on them. They usually let chain oil go into the crankcase so it fouls your spark plug. A lot of people plug the hole into the crankcase and just use the manual oiler

 

[heimannm]

The oil pump on that model is gear drive and located behind the flywheel.

Check compression, needs to be 110 PSI or so in order to run, also check to make sure the muffler is not completely plugged up.

It never hurts to have another look at the carburetor and make sure the gaskets and diaphragms are in good shape and in the correct order. Also make sure the fuel pick up line in the tank has the filter connected and reaches all the way to the bottom. It is too easy to switch the fuel pick up line and the return from the purge bulb.

Mark

 

[Old2stroke]

If it won't fire with fuel or starter fluid, its either low compression or ignition. Since it already started, compression probably isn't the main issue, but something to check. Does that saw have ignition points or an electronic coil and did you remove the flywheel? Just because the plug will spark in air doesn't mean it will under compression pressure in the engine, gap a plug to 0.080" and see if it will still spark. Spark timing has to be close to correct so could be an issue depending on type of ignition.

 

[BobL]

Thanks again to all who replied.

There's plenty of oil - I've cranked it so much its dripping of the bar
I've cleaned out the muffler.
There's heaps of fuel coming through. Again, I have cranked it so much there's fuel drops coming out of the muffler. Then I have to wait for the internals to dry out
I'll check out the plug and carburettor.

 

[link]

Thanks again to all who replied.

There's plenty of oil - I've cranked it so much its dripping of the bar
I've cleaned out the muffler.
There's heaps of fuel coming through. Again, I have cranked it so much there's fuel drops coming out of the muffler. Then I have to wait for the internals to dry out
I'll check out the plug and carburettor.

Its kinda funny (no pun intended) because a two stroke engine is a really simple concept.
Fuel, spark...

 

[BobL]

Its kinda funny (no pun intended) because a two stroke engine is a really simple concept.
Fuel, spark...

yeah - I agree. I've picked up dozens of old saws non-running saws from kerbsides, dumpsters, or had them given to me (in far worse shape than this one) and always managed to get them running. Must be losing my touch

 

[SteveSr]

I dont have a manual for this saw so I don't know the required gap so I gapped the coil/fly wheel using the two pieces of printer paper method (80 thou')

.080" is WAY too much gap should be around .008"-.012". I'll let you convert to mm if desired.

The primary coil tests out at ~5 Ω sale the secondary is ~870 Ω

If this is an electronic ignition module the primary resistance is irrelevant if not it is about right.

870 seems kind of low for the secondary. Normal secondaries are around 2.5-5K ohms.

@heimannm You speak McCulloch.

 

[heimannm]

I have my assortment of ignition specifications on the computer in my office in the museum. I'll try to remember and have a look tomorrow.

Some of the electronic coils have much lower resistance in the secondary than you might expect.

Mark

 

[cookies]

try pulling the plug and turning it upside down to drain excess fuel. Either the plug/coil are breaking down under compression or you have excess fuel in the crank case. Are there supposed to be clamps on the pictured intake boots?

 

[BobL]

Thanks again everyone - I'm gonna nail this one if it kills me.

.080" is WAY too much gap should be around .008"-.012". I'll let you convert to mm if desired.

Sorry I meant 0.008"

If this is an electronic ignition module the primary resistance is irrelevant if not it is about right.
870 seems kind of low for the secondary. Normal secondaries are around 2.5-5K ohms.

5kΩ is my experience as well but i've only measure this on Stihls before.

I scrupulously cleaned the carby, inspected the gaskets and diaphragms over a strong light and using a head magnifier.
Checked compression ~130psi.
Also dropped the spark plug gap to 20 thou.
The good news is that it now starts but still only runs for about 10s. DOH!

Now I reckon I have the primer bulb delivering fuel to the wrong side of the carby!

Fortunately I tock a picture before I tore everything apart.
The hoses look solid but they disintegrated as soon as I touched them.
The two open hose ends were attached to the primer bulb which has itself disintegrated

I copied this exactly, but what I did not know was, what was attached on the inside tank side of A and B as there was just bits of disintegrated hose and a dirty fuel filter laying in the bottom of the tank
I assumed that B was the long hose attached to the filter that goes to the bottom of the tank and A is just a return of some kind that terminates just inside the top of the tank ie not down into fuel?
This has the bulb pulling fuel up from tank through hose B and delivering it to the carby via hose C.
But, this delivers fuel to the wrong side of the carby - shoulda worked that out some time ago - DOH!!!

I'm not going to be able to try reversing these hoses for a few days as I'm tied up with other things but it would be worth knowing if I am on the right track.

Thanks again to everyone - much appreciated