3 - Stihl 028's resurrection thread--or trying to

[HarleyT]

 

[pioneerguy600]

I'm just gonna comment (I may be wrong) so when the carb is functioning properly, does the impulse line provide the vacumn or pressure needed to activate the diaphragm providing the fuel?
the engine gets the fuel through the main jet...now doesn't the remainder of the fuel cycle back to the tank in the return line? And if that passage is clogged (and by the look of those they probably are) or restricted excess fuel will be forced into the engine, causing a flooding condition. Or maybe the tank vent in stuck and the tank is being pressurized

The impulse line provides both types of pressures as the piston moves up and down in the cylinder, this push/pull signal is referred to as impulse and it moves the fuel pump diaphragm up and down in the carb thus pumping fuel up from the tank. There is no return line on an 028 and I have never seen a return line on any chainsaw. The metering diaphragm controls the amount of fuel allowed into the carb by pushing down on the metering lever which then lifts the needle valve off its seat allowing fuel in, when no more fuel is being called for the spring under the metering lever closes the needle valve. There are also other forces involved here such as atmospheric pressure but my explanation is the short story of how the fuel gets into the carb.
Pressure in the tank will not affect a good working carb, they are designed to work with that.

 

[Frogfarmer]

I've had problems with Tilly carbs flooding saws in the past. The design allows fuel from the reservoir in the carb to bleed into the intake tract. When they are right they start very easily and when they have issues they flood. Stick with the walbro and don't look back.

 

[Gear_head]

Sticking with the Walbro may be exactly what I do

Took the Tilly apart, and I'm fairly sure I had it right. I'll post pics just to confirm since that was mentioned earlier. At this point, I'm gonna clean it one more time and if it's not right, this carb is going in the parts bin. If I am able to bring the other two saws back to life, I'll prolly just order a new oem carb when the time comes.

Thanks for everyone's input

 

[pioneerguy600]

I prefer Tilly`s over any carb but then I have been working with them since the 50`s, we all seem to like what we know best.

 

[Gear_head]

I rebuilt that walbro carb and it fired right off. I was able to start tuning it and now need to put it to the wood.

I soaked the Tilly again and will try it on the next 028 I'm re-doing

Final product

 

[Stihlofadeal64]

Love it. You did a good job on the clean up!

 

[LoveStihlQuality]

What is your starting procedure?

I think those have the choke built in the air filter. You might want to check that. If it is somehow malfunctioning the choke could be stuck.

Welcome to the club!!

Yes, choke in AF

LoveStihlQuality

 

[LoveStihlQuality]

I rebuilt that walbro carb and it fired right off. I was able to start tuning it and now need to put it to the wood.

I soaked the Tilly again and will try it on the next 028 I'm re-doing

Final product

I have a soft spot for these. A+ !

LoveStihlQuality

 

[drf255]

I have one I ported and have nothing but problems with the Tilly. Won't hold high tune.

Jerry, what is the replacement Walbro number for the 028S?