disconnect pistons from rods

[gs850cafe]

ok silly but quick question...how do the wrist pins come out in the 850 motors..

any help would be appreciated
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[49er]

ok silly but quick question...how do the wrist pins come out in the 850 motors..

any help would be appreciated
​

Pry out the circlips with a small screw driver blade, then use an extractor to draw the pin out. Don't try hammering them out with a pin, or you risk damaging the pistons and bending the con rods.

You can make an extractor by using a length of threaded rod or a long bolt, a tube that is slightly larger in diameter than the wrist pin bore, some washers and 2 nuts. The flats on the bolt head or a nut (if using the threaded rod) should be slightly smaller than the pin bore, so it can be drawn through the bore without damaging it.

Enjoy!

 

[slyone]

also here's the manual above box..http://members.dslextreme.com/users/bikecliff/

 

[chuck hahn]

Unless the wrist pin or the rod bore itself is damaged, they just slide out by finger pressure...usually.

 

[bwringer]

I've usually needed to make an extractor from some 1/4" threaded rod, some washers, nuts, etc. It doesn't take much force, but it's almost always more than you can develop with your fingers.


All the manuals are very clear and precise in the instructions for this. I would strongly suggest obtaining one...

 

[Nessism]

As chuck suggests, you can usually just tap out the pin. Just don't hammer on the thing if it's stuck. I've rebuilt a few different GS engines and never used any special tools to get the pins out.

 

[MisterCinders]

I tapped mine out with a smaller deep socket or socket extension. Just pick one that is smaller than the pin and the circlip, like an 8mm deep socket IIRC. A few taps on that, and the pin should move out. Once it starts to slide, finger pressure will finish the job. If it snags at the end, give it a few more gentle taps.

HTH

 

[blowerbike]

pecking or beating the pin out can and will bend the rod if much force is used.
purchase or make an extractor.
i have never been able to just push the pins out on a factory GS engine.
drag bikes or modified street bikes are a different story..plus buttons don't put a bur on the pistons.

 

[tkent02]

I use a big C clamp and a couple sockets. It doesn't take much to get them started.

 

[chuck hahn]

If you can bend the rod with a few persuasion taps from a drift , then youve got some pretty chitty engine parts to begin with. They arent in there very tightly by any means.

 

[MisterCinders]

If you can bend the rod with a few persuasion taps from a drift , then youve got some pretty chitty engine parts to begin with. They arent in there very tightly by any means.

+1 this. I don't recall even using a hammer. Just tapped the socket or extension with a screwdriver handle or wrench, depending on what was handy.

 

[blowerbike]

If you can bend the rod with a few persuasion taps from a drift , then youve got some pretty chitty engine parts to begin with. They arent in there very tightly by any means.

rods are designed to go up and down not side to side.
ask me why i have a pin puller now...yep, bent 1 of 4 rods on an 1100 years ago.

FYI
wrist pins can and will gall in the small end of the rod....no pushing it out without force/puller.
if you take enough engines apart a person will find these quite often.

 

[49er]

rods are designed to go up and down not side to side.
ask me why i have a pin puller now...yep, bent 1 of 4 rods on an 1100 years ago.

FYI
wrist pins can and will gall in the small end of the rod....no pushing it out without force/puller.
if you take enough engines apart a person will find these quite often.

I agree. If you can push them out by hand the engine has very low mileage on it and/or the pin clearances were excessive from new.

High mileage engines often have pin galling and a build up of baked on oil/gunge to prevent finger pressure removal.

 

[chuck hahn]

Just took down the 78 750 that had just over 48,000 original and had never been into before. Only one was sticky and a slight tap with a brass drift had it out with no fuss...the other 3 slid out woth a push of the finger. We found some of the factory case sealer chips in the oil galleys though. Other than that it was as easy as that.

 

[gs850cafe]

awesome ty very much guys...also do i have to remove the engine to put rings in my bike?

 

[hampshirehog]

awesome ty very much guys...also do i have to remove the engine to put rings in my bike?

No. You don't need to remove the pistons to put on new rings either.

 

[chuck hahn]

Pull the head and the jugs, clean the pistons free of all carbon, install new rings and reasseble the top end. Chore Boy, wire brush and solvent, things like that will spiffy up the tops in short order. May as well do stem seals and have the valves freshened up since it is apart.

 

[blowerbike]

awesome ty very much guys...also do i have to remove the engine to put rings in my bike?

you do need to remove any carbon from the ring lands and a nice blasting of the pistons tops would look good....some people soak there pistons in berrymans..your call.
you can break an old ring in half and scrape the ring land if you don't have a ring groove tool.
all can be done with engine in frame of course.

 

[chuck hahn]

Good tip on using a snapped off ring as a groove tool...I will remember that

 

[gs850cafe]

No. You don't need to remove the pistons to put on new rings either.

i know that much..my bike needs rings...just didnt know if i had to pull the engine out