When I'm going to rebuild a two stroke glow engine I pull the sleeve then fiddle fart and worry the piston/connecting rod until I am able to get the rod off the crank pin. To date I have never lost the battle. I just got a call from a friend having the old rod crank pin removel problem and the only pearls of wisdon I could give him is to keep moving it around and worry it to death until it slides off. If you can't get it bring it over, it's no easier for me but I always get the rod off the crank.
My question to others that have had the same battle, has anyone come up with or found an easy way to get the rod off the pin. Perhaps a magic spot where the crank and rod line up so it will just slide off.
Four strokes are just smoother to work on. Other then forgetting to replace the lifter tubes once in a while they don't fight you like these little two strokes.
Just wondering.
Gene

I always suggest using a bigger hammer (Just me, sorry). [&:]
Wiggle and twist 'til it works?

Typically, there are 2 situations...
One is where there is a hole in the rear of the case, and the wrist pin needs to be removed from the piston / upper end of the rod before you can get the rod off the crankpin.

The other is typically caused by gum / varnish or rust on the wrist pin, keeping the upper end of the rod from sliding back far enough to get the rod to come off the crankpin.

Both can be fustrating.

The gum / varnish needs to be softened or removed. Acetone, carb cleaner, or some such solvent...then PB Blaster or penetrating oil, and heat can help to get the wrist pin free enough to slide the rod back. A zip tie around the upper end of the rod can give you some leverage to pull on it too. Work the upper end of the rod back and forth on the wrist pin to work in the solvents and lubricants.

The same sort of gunk can cause problems getting the wrist pin out through the hole in the rear of the case...(more typically found on 4 strokers )

It can take time...lots of wiggling and jiggling...some cursing (optional ) and patience...

Sounds like he hasn't used filthy enough language to me. Sometimes it is a requirement for tough jobs.

He got it. I was just hoping someone had a better way then just swearing at it. He used the fiber tie behind the rod and tug method. He did bring it over for bearing removel. Front one no problem. Rear bearing was so tight I couldn't get my removel tool behind it. I taught him the heat and slap on wood method, fell right out. {{after three tries}} I taught him some new words too when I had a slight slip on the hot case.[:@]

What kind of removal tool do you use for the bearings? I had an engine once that wouldn't let the thing go with heat and I wound up grinding on it and yanking it out. Engine ran well afterward though.

Just a little home made tool made from piano wire with a short tapered end. I can usually get it into the little groove between the case and bearing then just give it a yank. Doesn't always work. It was something shown in a very old book on rebuilding OS four strokes I have. In this case tonight the engine was an OS .55 and the case was broken in a crash. My friend finally got tired of fixing it with JB weld and bought a new case. Before he went home it was decided to give it one last try. I used my small hand torch and heated the case on the outside at the bearing area and just below. One good wrap on my building board and the bearing just fell out. It took the torch, I usually just boil the engine in water and give the bearing a slight tug and they come out. This one was really in there. I really cooked the case, heating may be an understatement.

I made a handy tool for removing stubborn rear bearings out of a cheap screwdriver.
I took a std. flat blade (about 1/4" wide ) screwdriver, and bent just the tip (1/8" ) over 90 degrees. Then I ground it thin enough to catch on the inside edge of the inner race of the R. bearing.
Put the case on a block of wood with the front bearing opening pointing straight up. Heat using your favorite method...and go down in thru the F. opening with the tool. Catch on the lip of the inner race w/ the bent over edge of the tool, then tap gently but firmly w/ a light hammer. Reposition the tool between taps so you don't get the bearing cocked in the bore as it's driven out.

This method has never failed...

That's what I have only made out of a piece of piano wire. Last night when I was working on the .55AX the problem was there was no lip to snag onto and the bearing was seated flush with the case. Some nice maching in there. Anyway, the tool is what I usually use but I do wonder if perhaps the service centers don't have an expanding tool of some type??Just wondering but the real question was about an easier way to remove the connecting rod. I have worked on some engines that seem to have more room so they just pull right off and some you just swear at until it comes off. Seems the swearing thing is used by most everyone.
A couple weeks ago I did a rebuild on an OS .91FS and the engine was back together in less then 10 minutes. No fight, no swearing, it just went back together smoother then I have ever seen. Sometimes it just happens.

I disassembled an old OS FS-40 last night that I just bought, but I haven't been to take off the bearings yet. Could you guys post a picture of the tool that you use to remove them. Thanks.

Tool and book. The book of course is geared to the older engines but other then a couple of very minor things the engines are still pretty much the same. These little books were what we used to buy before computers became the rage.

I just read the how to make part and I wanted to mention I didn't heat the music wire. I bent it in my vise like I was bending landing gear then I cut it off at the bend and ground it to shape. Heating it removes the temper in the steel.

Hmmm, learn something new everyday (whether I want to or not!!!!)

I've always heated the case and slapped it on wood to knock the bearings out. I'll have to try making a tool like that and try next time I replace bearings.

Thanks guys

Ken

RCKen, Im sending you a pm.
Thanks,
John

Hey yeah...there ya go...[8D]
I used a "Carburetor screwdriver" which has a longer shank...close to a foot long w/ the handle...easy to hold on to and the handle is easy to hit w/ the small hammer.

6 of one...half a dozen 'o the other...

Some of the engines I have worked on were sitting in a damp basement for a couple decades...so they were rusty, and some were varnished in addition to the rust...those rear bearings were NOT gonna budge with the "whack it on a block of wood" method...more agressive persuasion required.