Help!!!! 1984 gl1200 Engine won't make full rotation

I have bike I bought that has sat for awhile the number 4 cylinder was rusty and 3 a little. Went to change timing belts but motor won't turn much it seems to hit something. The number 4 cylinder the piston seems all the way up and 3 is almost up. What can do this? Ddo I have to pull head?

If you removed the old belts already it may be valves are hitting.

well if it was me ...id pull the heads ...sounds like the belt might off timed or there so corrosion you have a stuck valve or rings stuck to cylinder ...big gamble to not hurt rings by forcing movment ...id take belts off heads with out moving anything and then take heads off so you can clean up cylinder and inspect heads for bent valves ....

Since you know there is some rust. I agree the best thing would be to remove both heads and go from there. After 30+ years the head gaskets are on borrowed time if they still seal anyway. Welcome to the fun!

Curious how you know there is rust, sounds like you've had the heads off already?

In case you don't know, these engines are zero clearance so if belts are removed and any valve is open even slightly, the piston will hit it and damage the valve.

#4 and #3 piston are positioned exactly the same on the crankshaft so they will be the same at top. If not there is something else wrong internally like a bent rod but don't assume there is.

hmmmmmm heads off for sure ....on this one

Thanks so far but I did stick a camera down there and I also pulled out a bunch of rust and one single strand of wire also with a magnet. Zero clearance means it is hitting a valve since the left side doesn't turn easily. The right does turn smooth.i noted that . If the camera doesn't turn easily then is it a good chance that the valve is bent.

You've found rust in the cylinder right? If so the best path is pull the heads.

I would agree, pull the heads. If cylinder walls are rusted I would want to run a cylinder hone down each cylinder, this would require disassembling the engine. If you force the pistons past the rust you will most likely damage or break rings meaning engine would need to come apart to replace the broken rings.

I am not able to do that much with what I have. If it is just one cylinder then is there a way to clean up the top of that one without total teardon ? I still have a clutch that won't build up pressure and rear brakes that don't compress both pistons .

Replacing head gaskets isn't that difficult and seeing the actual level of rusting can possibly show viable options over a complete tear down. Big concern here is pitting and scale. Once apart the heads and valves can be inspected along with condition of the rusted cylinders. It may still be a relatively easy fix or maybe you will want to source another motor. Pictures after head removal can tell the tale.

a bike this old and non running is going to have to have work done to it to properly bring it back ...taking head off of bike will tell the story on the motor ..heads and all ...there are many write up threadfs with pics to look at to get a feel of whats invloved ....made to care ....has a bike and was rather iffy about doing things ...and got through it ....many threads here with pics and all about taking heads off ...cleaning things up and can be done without honing and be great bike ....the hooch bike was a rather bad looking motor insde ...and is now a one of kind superwing so to speak ...but there things done to it that made it different than all others ...all done from the spot of taking heads off and cleaning cylinders up and forward back together from there ....it great to challenge yourself past your comfort zone ....

Thanks everyone I will pull head and take look and make pics. I am poor any suggestions on cheapest gaskets?

me too i buy the cheapest gaskets and those will run bout 50$ a set ...there usually are mis cut a bit ...but the one twice as exspensive are really no better just cut better ,,,but first you just need to get heads off and pics up on forum ...once that done we will explain how to check other things out to test motors soundness

Vesrah makes a good quality gasket set, at a reasonable price, compared to Honda's. :good: You want a decent set of gasket's, :yes: leak's are messy on your floor's & yourself. :smilie_happy:

they dont make decent gaskets period denver ...there all goober and no metal to speak of

OK off with its head!!! I would like to let everyone know that it is my first bike since 2012. I hit a deer head-on at 65 on shadow 600 coming back from Laconia at 2 am. I am very lucky to be able to ride again. But it's a big deal

:good:

Gasket choices are few and the vesrah have a good record. Be very careful though to get 1200 gaskets if and when they are needed. Heads from the earlier 1100 or 1000 will fit a 1200 but the gaskets from them will not last.

It sounds like you have your work cut out for you. As already stated, one you get the heads off post pictures. Everyone understands money issues, but when it comes to a motorcycle you want it right because you don't want it leaving you along side the road somewhere.