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

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Gear_head

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I have been in the shadows of this site for some time. I have researched and researched topics here. Even so, I find myself somewhat chasing my tail on this one.

Some background .....Long story short, I live on an acre in the country with many trees. I had a store bought Poulan that was a gift, but we all know those can leave a lot to be desired. I have a large tree that needs to come down this spring, and that is where my gently used 025 and MS441 come in. I love nice tools....

I recently scored 3 028's for cheap. Not as a money maker, but because I like to fix and clean up good machines. So this is not for profit. Enter the first 028, a super. I cleaned her up and made her look nice assuming I had getting it running under control.





after a fresh carb rebuild, new:
impulse hose, 2 plugs, fuel line, vent line,

I can not get the saw to run more than a few seconds on the first pull. After that, I get nothing. When I pull the plug, the plug is wet and I'm getting a little bit of running fuel out of the carb enclosure.

I have been thru the carb 3 times. While it might still be plugged, the gasket order in definitely correct. The metering lever is adjusted with the bottom of the carb floor, per the Tillotson website.


The needle appears to be sitting on the seat with no obstructions. H/L are set at 1.25 out as the sticker says it should be from factory.

the saw has an electronic ignition, but it was CAKED with crud when I first got it. I cleaned out the entire flywheel area, but did not remove the flywheel or electronic ignition. I am wondering if there is anything on that electronic ignition that needs to be lighting cleaned with sandpaper? The gap between the ignition and flywheel is spot on. I have no idea on timing, that I still need to research. Spark is a good crisp blue, using a Bosch plug as the local "dealer" recommends. If I take a spare plug and bend the electrode gap to 1/4' plus, the spark is half blue-half orange.

My compression gauges are junk. They dont show above 40 psi on my good saws, so I may need to order a new one, although I don't feel that is my problem. The exhaust side of the piston looks great, although I am not sure how to identify if I have a stuck ring, like I have read about. I have a vacuum gauge and I have pressure tested my dirt bike's engine every time before putting it back into service. I am not opposed to either of these tests. I'm about out of ideas at this point.

Anyway my background began with 2 stroke dirt bikes, my 65 Mustang, and just simply wrenching on anything that needed fixed. This winter I am only 1 for 4 on fixing some saws I have acquired. Granted the other 3 are Macs, but I am starting to question why these simple machines are giving me fits.

thanks for any help
Ryan
 
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!!
When I wrote my book above, I meant to add that I have a good clean filter on it. It is the thin screen winter type that allows the choke flap to be somewhat seen. The choke looks to be closing as it should. I have tried various starting methods, with and without the choke. I very well may be flooding the saw with my repeated pulls. I've tried several pulls with choke, and I have tried flipping the lever up one off full choke with the saw fires off on the first pull. Nothing seems to get it to fire off again.
 
So two three pulls on full choke it should pop. Move switch up a notch. First pull it should start to run, let it run for a few seconds then blip the throttle trigger. It should go down to idle. Assuming all is good.
 
So two three pulls on full choke it should pop. Move switch up a notch. First pull it should start to run, let it run for a few seconds then blip the throttle trigger. It should go down to idle. Assuming all is good.

I will try again, but after that first pop I get nothing after that
 
I'm thinking the next move is to take
One of the carbs off the other 028's and see if I can duplicate or change the issue
 
I appreciate everyone's responses, we have success and now more questions. So I grabbed the Walboro carb off the 028 WB with a plastic fuel tank, because it had the cleanest air filter on it.

The saw fired right off and sounded good. I had to shut it down because I was in my basement and there was no gas leaking out of the carb assembly as well. The question is now, what did I do wrong with that stinking Tillotson carb. I pulled the needle, checked the seat, and everything looked flawless. I will finish taking it back apart tomorrow morning and take pics so everyone can double check my work. I will be down right embarrassed if I did, since I had the Tillotson diagrams pulled up as I did it.
 
this is the carb rebuild kit
http://www.baileysonline.com/Parts/...05-Carburetor-Repair-Kit-Tillotson-RK14HU.axd

new in front, old in back. I feel like it is something simple like this that I am overlooking.


Ok, your diaphragm looks the same so that`s good, some kits have different diaphragms. It still seems like there is something wrong and the needle is not sealing. The gasket has to be against the carb body with the diaphragm on top against the cover, if not the needle will be held open. Check for that and let us know what you found.
 
Can anyone tell me what that metal washer does, it goes between this carb and the rubber intake boot (not really between though). This saw was missing it when I got it, but the saw with the wallboro carb had it. I swapped it when I swapped carbs. Now I'm wondering if it didn't contribute to the problem.
 
Not all carbs are the same. Make sure the kit you got matches the carb. Each Waldo carb has a number on the side. Depending on the year, the carbs will be different which will affect the kit a bit.
 
Also make sure the impluse line is ok. Might be hurting the pumping action
It's new and I can breath in and out thru it, leading me to believe it is free of obstructions

The carb kit in the picture was advertised for a tillotson 40 (enter letter here) kit. Don't remember the letter at the moment
 
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
 
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