HELP! Ported 026 Problems

[crane]

I would take a good look at your intake boot since thats something that I could see getting in the way or getting torn or not sealing properly for you. On my last rebuild I put the boot on the jug first, then had to pull it through the hole in the handle. If its been sitting, it could have been brittle and now has a tear in it somewhere that you didnt notice before.

Also, did you replace the impulse line when you had things apart to do the porting?

Excellent point. When you pressure test the saw, make sure you flex the rear handle on the anti vibe mounts. That will flex the intake boot a little and if there is even a small leak, the needle will drop. If it holds under pressure, try a vacum. I've seen seals, boots that will hold pressure, but fail under a vacum and vise versa. That tester your going to buy will get used a lot more than you think. Handy for tracking leaks. You'll also use it to test carbs after a rebuild(see if the intake needle or seat leak, bad or misaligned gasket). It is well worth getting a good reliable one.

 

[w8ye]

Your wanting to perform a Vac/Pressure test, NOT a leakdown test. That is for engines with valves. I.E, Stihl's 4Mix engines. In this case all you need is a good tester from an auto supply store. Mitey Vac makes a good one that will do both vacum and pressure. It is a good investment if your working on saws. Then all you need from your Stihl dealer is a sealer plate(0000 855 8106), about $1.50, to seal off the exhaust. You can also use a piece of cut inner tube, but the dealer one is cheap enough. You'll also need a flange(1118 850 4200), about $20. This bolts on where your carb is now, and allows you to introduce the pressure or the vacum.
Block the muffler off with the sealing plate, bolt on the flange, make sure the decomp is not pushed in if you have one and apply pressure to the saw to a max of about 7psi. It should hold it for a minimum of 30seconds. If the needle drops, get out a spray bottle of soapy water and start looking for the leak.

This is not so black and white like this. There is a PASS-FAIL specification. The chainsaw should not loose more than 1-3/4 pounds pressure in the 30 seconds. All chainsaws are going to loose a little pressure. If your saw is getting close to loosing 1-3/4 lbs in 30 seconds, I would start looking at the crank seals, boot, base gasket, etc. Otherwise, the chainsaw passed the pressure test.

 

[griffonks]

Maybe cylinder gasket since it was reused? Impulse hose cracked?

 

[Woody33]

Rockjock has set me straight about which pressure/vac tester to get in a PM (thank again, BTW). I'll be picking one up today. I literally cannot wait to get my hands back on the saw!

 

[crane]

This is not so black and white like this. There is a PASS-FAIL specification. The chainsaw should not loose more than 1-3/4 pounds pressure in the 30 seconds. All chainsaws are going to loose a little pressure. If your saw is getting close to loosing 1-3/4 lbs in 30 seconds, I would start looking at the crank seals, boot, base gasket, etc. Otherwise, the chainsaw passed the pressure test.

You are correct. I should have clarified that a little more clearly.

 

[Mastermind]

If you pulled the jug by working the intake boot off the jug and then back on, you may have damaged it. Also look very close at your fuel line.......pin holes and cracks are very common.

 

[Woody33]

If you pulled the jug by working the intake boot off the jug and then back on, you may have damaged it. Also look very close at your fuel line.......pin holes and cracks are very common.

Ya, those are the first two places I will check. I removed the four cylinder bolts and lifted the cylinder off the piston while removing the intake boot at the same time to try and lessen the abuse to the boot vs. trying to pry it off first but getting it back on was another story... definitely needs a once (or twice, or three times) over.

I may as well replace the fuel lines while I'm there.

Question: Should I replace like for like (regarding fuel lines, filter etc.) or since the saw has been ported should I upgrade the lines and filter to a larger size for better flow?

Thanks!!

 

[z71mike]

Like for like.

 

[Mastermind]

Ya, those are the first two places I will check. I removed the four cylinder bolts and lifted the cylinder off the piston while removing the intake boot at the same time to try and lessen the abuse to the boot vs. trying to pry it off first but getting it back on was another story... definitely needs a once (or twice, or three times) over.

I may as well replace the fuel lines while I'm there.

Question: Should I replace like for like (regarding fuel lines, filter etc.) or since the saw has been ported should I upgrade the lines and filter to a larger size for better flow?

Thanks!!

You're not going to need a bigger carb, fuel lines, impulse or anything like that. I do compression increases, port timing alteration, muffler mods, and ignition timing advance and still run all the stock parts.

 

[Woody33]

Ok, great thanks a bunch! I'm going to the dealer tomorrow. I'm currently in Southern Ontario but I actually live in northern Manitoba where dealers are few and far between so I want to make sure I get this saw running tip-top before I head back up for the winter in Nov. I can likely thank AS and the great members on here for that! I'll post a video if I can get the saw running

 

[crane]

If your struggling getting the intake boot on, try the string method. Install the boot on the cylinder. Use a slip knot on a piece of string. Choke it up on the edge of the boot then pass the other end of the string thru the carb mount plate. Pull on the string in a circular motion and you'll find the boot pops on thru. Remove string and done. This eliminates any prying or poking that can result in a tear or hole or just weakening the boot itself. Stihl sells some "press fluid" that works well to ease the boot thru.

 

[w8ye]

If your struggling getting the intake boot on, try the string method. Install the boot on the cylinder. Use a slip knot on a piece of string. Choke it up on the edge of the boot then pass the other end of the string thru the carb mount plate. Pull on the string in a circular motion and you'll find the boot pops on thru. Remove string and done. This eliminates any prying or poking that can result in a tear or hole or just weakening the boot itself. Stihl sells some "press fluid" that works well to ease the boot thru.

That's a real good tip

 

[Woody33]

If your struggling getting the intake boot on, try the string method. Install the boot on the cylinder. Use a slip knot on a piece of string. Choke it up on the edge of the boot then pass the other end of the string thru the carb mount plate. Pull on the string in a circular motion and you'll find the boot pops on thru. Remove string and done. This eliminates any prying or poking that can result in a tear or hole or just weakening the boot itself. Stihl sells some "press fluid" that works well to ease the boot thru.

Brilliant! ..why couldn't I think of that when I was cursing the thing!

 

[crane]

I stole that trick from the Stihl shop manual :msp_biggrin:

 

[crane]

That press fluid is amazing stuff. Kinda feels like baby oil. It evaporates after install with no residue. Great for fuel lines, seals, boots, installing new boots on spark plugs, popping grommets thru. It's works better than grease or oil as once installed it's gone. No lingering after effects. p/n 0781 957 9000

 

[Rockjock]

That press fluid is amazing stuff. Kinda feels like baby oil. It evaporates after install with no residue. Great for fuel lines, seals, boots, installing new boots on spark plugs, popping grommets thru. It's works better than grease or oil as once installed it's gone. No lingering after effects. p/n 0781 957 9000

Not gonna say who told me but it is much like ky jelly.

 

[fearofpavement]

Not gonna say who told me but it is much like ky jelly.

I keep a tube of that in the shop for some applications where oil/grease isn't desirable.