How to get stuck dowel pins out of the cylinder?

[GaSmoker81]

I've been trying for the last two days to get two dowel pins out of the cylinder. Rebuilding a 125 two stroke that was in need of some serious TLC.

Anyway..i've been spraying it with penetrating oil for the last two days and have been trying to pull these things out. At first I had a socket slid into the center of the dowel pin so I could grab on the pin and try and twist and pull it out. That hasn't been working.

Next I just forgot about trying to get them out (so they could be reused) and grabbed the lip of the pin and pulled. That hasn't worked either.

In retrospec I could of ran it with the pins stuck in the cylinder but I'm trying to rebuid this engine right after all the abuse its been through.

Lip of dowel pins are started to get messed up and there is no reusing these now so..I need to get them out.

[Hans Schmid]

I thought some dowel pins are supposed to be there, they are pressed in from the factory.....as for getting them out, I would heat the aluminum as it will cause the aluminum to expand, and then try to pull them out.

[SS109]

.....as for getting them out, I would heat the aluminum as it will cause the aluminum to expand, and then try to pull them out.

Yep, that is what I have done in the past to get them out. Sometimes they will just fall out after heating the cylinder.

[bigblu3]

get a 10lbs magnet

[GaSmoker81]

These are suppose to come out.

In my service manual it says to remove the dowel pins and in the picture the pins are in the engine case. Mine are stuck in the cylinder. Also in the reassemly stage it jsut says fit the dowel pins and again shows the bottom of the engine. That leads me to believe they are suppose to be removable. Also one pin is sticking out more then the other.

What do I heat it with. Just a standard heat gun? I could give that a try. Hopefully all the PB Blaster doesn't go up in flames.

Edited May 3, 2013 by GaDRZ400sMan

[Trailryder42]

Propane torch works good. Don't heat the pins directly, heat the cylinder around the pins.

[j753301]

I have seen people tear up the gasket surface from stuck dowel pins trying to get them out. When i run across stuck dowels i just leave them in,its not gonna hurt anything.just clean the area real good and it will be fine.

[rpt50]

if they are hollow, put a drill bit inside to keep it from collapsing, and a washer over the outside to protect the gasket surface. Grip it with pliers and twist it out. Heat helps too. You can heat the aluminum, and then touch the pin with ice for maximum effect.

[Polar_Bus]

If the pins are being real stubborn, put the cyl in the freezer overnight, then quickly heat the aluminum around the dowel have your vice grips ready, and pull. They should come out easy.

Edited May 3, 2013 by Polar_Bus

[GaSmoker81]

I GOT THEM OUT!!!!

I actually had a stroke of genius at 3:30 last night and developed a pretty good method for getting them out. So if your past the point of reusing the pins and they are stuck in the cylinder then all you need is a punch pin set, some painters tape, and some needle nose vise grip piers.

I put some tape around the end of the needle noes pliers (seems to grip better) and then clamped those onto the bottom of the dowel pin (very tightly). Next I inserted a large punch pin into the top of the hole (where the nuts go to tighten the cylinder to the bottom end) and let it rest on the end of the needle nose plier (that's inside the dowel pin). I got a small hammer and was able to remove the pin by hitting the needle end of the pliers with the hammer. I did use lots of PB blaster and moved the pliers around to different spots on the dowel pin.

Worked great. If that didn't work I was about to break out my butane torch and go for the heat method.

Edited May 3, 2013 by GaDRZ400sMan

[bigblu3]

Propane torch works good. Don't heat the pins directly, heat the cylinder around the pins.

no dont heat it up, it causes the engine to over heat (basically like a broken head gasket). and it will cause the surface to become un even

[GaSmoker81]

I'm glad I got it out before having to use heat.

[KTM_Pat]

Why were u tring to remove them? Bent, , busted, ?? Never had problem just leaving them in. Of course past the fact now right.

[William1]

Assuming they are stuck, I remove them using a very large sheet metal screw. It only needs to just begin to 'bite' on the dowel. The effort to turn the screw often breaks the dowel loose and then can be easily pulled. By having he screw only be able to grab the top of the dowel, keeps it from expanding in the cases and being even harder to remove. A screw also retains the shape of the dowel.

[GaSmoker81]

Why were u tring to remove them? Bent, , busted, ?? Never had problem just leaving them in. Of course past the fact now right.

Just one of those things. Service manual said they were removable so I tried to pull them out and ended up scratching and slightly bending the end of one. Its all good now though. Got the old ones out and my new ones just came in the mail today.

[Sturges1.33]

I have a similar issue but my dowel pins are stuck in the crankcase. Looking back now I realize I could’ve left them in but it’s too late now. They’re deformed as I tried to use pliers to remove them. Someone suggested using heat. Would that be okay to do on the crankcase? I’ve been trying penetrating oil but no luck.

 

[Sullysully]

55 minutes ago, Sturges1.33 said:

I have a similar issue but my dowel pins are stuck in the crankcase. Looking back now I realize I could’ve left them in but it’s too late now. They’re deformed as I tried to use pliers to remove them. Someone suggested using heat. Would that be okay to do on the crankcase? I’ve been trying penetrating oil but no luck.

 

Yeah heat is the only way they’ll come out. Just try to do it evenly so you don’t warp the case. It shouldn’t take a ton of heat. When you replace it we often use a bit of yamabond to seal it in there.