rebuilding 2-stroke engine

[btuser]

I've got a Solo 471 backpack leafblower that I've owned for about 12 years. For the first 11 years it was a flawless machine that starts every time as if it was brand new. Then I let someone borrow it.

Let me pause a minute so I can swallow the rage that threatens to boil out of me.

Ok, so I get a call from the used-to-be friend who's also my sister:

"I'm having trouble starting it"
"Are you using the choke?"
"What's a choke? Nevermind. It started about an hour after I added some new gas-"
"What new gas"
"I went to get some gas for the blower-"
"Did you mix it?"
"Yes. Was I not supposed to?"
"No, you're supposed to mix it of course."
"There was only a little left-"
"Little of what left?"
"The gas you gave me."
"Well, did you add the f*cking oil I gave you to the new gas?"
"What oil? There's no place to check the oil! Stop yelling at me!"

Needless to say, now it's running a little rough. I'm guessing I'll need to replace the piston rings. The blower blows a lot of blue smoke untill it gets hot. Still has compression, but it doesn't have the same power.

 

[WES999]

I have rebuilt a few chainsaws with toasted engines. You should get a piston and ring kit.
Replace wrist pin bearing also.
If it has a chrome plated cylinder you can use muratic acid and some fine sandpaper to remove the aluminum stuck to the cylinder walls. It will take some time but you can often recondition a ratty looking cylinder.

If you go to http://www.arboristsite.com/ the chainsaw forum has a lot of good info in how to use muratic acid, and general rebuilding info.

BTW I will be by later to borrow the Still, I have plenty of gas. ;-)

 

[Nic36]

This isn't really of any help to you, but we have a common saying that we use at work (all the time):

"No good deed goes unpunished."

It is so true.

 

[RNLA]

Yes you got a burned piston, or stuck, or any other term you want to use. You should be able to get a piston and ring kit easily. You can have the cylinder honed to clean it up. I have been told that the cylinder does not have to be plated to work. I may be wrong but I have seen a plated cylinder get honed and stuck back on the motor, ran great on a motorcycle.

 

[btuser]

I'm guessing its burned. It still "works" and has never siezed, but the cobustion efficiency is shot. I'm very careful with the mix and have never had such a choking blue smoke coming from it. I've checked the muffler for back pressure and found none, fuel lines good. Its just not the same blower. That woman is dead to me. At least 'till Thanksgiving.

So, while I'm at it is there anything else? I know I'm not going to be able to tell untill I pull the old one but will I definately need to replace the piston?

 

[semipro]

I'm guessing its burned. It still "works" and has never siezed, but the cobustion efficiency is shot. I'm very careful with the mix and have never had such a choking blue smoke coming from it. I've checked the muffler for back pressure and found none, fuel lines good. Its just not the same blower. That woman is dead to me. At least 'till Thanksgiving.

So, while I'm at it is there anything else? I know I'm not going to be able to tell untill I pull the old one but will I definately need to replace the piston?

I'd think you need to inspect the crank and rod bearings well. Some 2 strokes use needle bearings, some use babbit(sp) bearings. All depend upon the oil in the fuel for lubrication.


I've invested in 4-strokes for all my light equipment except chain saws. I love the fact they are much quieter and I don't smell like 2-stroke fumes after using them.

 

[WES999]

Get a piston kit, piston, rings, bearing, wrist pin, clips.
Also you should replace the crank seals.

The crank bearings will likly be OK.

When I rebuilt my Husky 36 I replaced the piston and rings, and found the crank seals were leaking when I pressure/vacuum tested, I had to take it apart again. I won't do that again.

 

[smokinj]

pull the muffler check the clinder wall if its scored, total rebuild is in order...

 

[ROBERT F]

Pull the spark plug and check the cylinder walls and top/sidedges of the piston that way as well. look for metal fouling on the spark plug. with the plug out, shine a light down the hole and slowly pull the starter cord(dont recommend this method with any of the starting assist models) and when its at BDC you should be able to see a fair amount.

 

[WES999]

Lots of good suggestions, you may want to do a compression test, it will tell you a lot about the condition of the top end.

 

[btuser]

That's for the help. I'm trying to find the parts for a rebuild.