GK76 Engine overhaul-What do you recommend?

[Marsbar]

I forgot to add that it was my #3 cylinder that was leaking as well. That pressure test led to the whole engine rebuild.

yes its my number 3 cylinder also. never done this before so i dont know what im looking at yet.
the bike would just cut out when at lights. the reason why i did the test. the book says standard is 159 psi, anything below that needs overhaul.
Cylinders
1 = 120
2 = 150
3 = 40
4 = 115

Going to be taking the engine out the frame Saturday and got a bench to put it on to work on. been told new rings and valve seats most likely.

Ill post few pics of mine on a new thread on Saturday. Unfortunately dont have the money to do anything as nice as yours. Using push bike to get around now is

[rgvsp]

Here is a small update. I got side tracked from the pipes when I decided to get the rust out of the gas tank and found out the damn thing leaks. That combined with the dents persuaded me to just go ahead and take the time and strip the piece of shit down and fix everything.



This was news to me. The tank had been repaired once already apparently as this mess was filled with Bondo.



Hopefully I'll have an update on the pipes being welded in then the next couple of weeks. Then, if I can fix the tank up it could be started for the first time.

[rgvsp]

Well I couldn't leave well enough alone and found a really nice braced GK73 swing arm. Has anyone actually done this conversion on a 76? I saw a couple of threads that said this was a straight swap. Can anyone confirm or deny?

[Andy]

Well I couldn't leave well enough alone and found a really nice braced GK73 swing arm. Has anyone actually done this conversion on a 76? I saw a couple of threads that said this was a straight swap. Can anyone confirm or deny?

Bolts straight in,look at my 76a(the mrs`s)

Regards
Andy

[rgvsp]

That is good news. Thanks Andy.

[rgvsp]

The GK73 swing arm arrived today. I stripped it down and gave it a quick cleaning. I think I got really lucky, it looks to be in excellent shape and was a bargain at $35. The bearings even appear to be in great shape. Shipping wasn't a bargain: $150. I hope to get it on the bike this weekend.

[Marsbar]

WoW not bad for that, looks brand new.
Av finally posted up me project in the project section. i welcome any help/advice ect

[rgvsp]

Had some time today so I got the 73 swing arm on. This is what I learned.

The swing arm was 2mm too narrow at the swing arm pivot and needed spacers. Two washers under each dust cover did the trick.

The swing arm was 2mm too narrow at the rear. I took 2mm of the rear brake assembly at the top. There is a nice little lip there you can file/grind it down.

The 73 arm is definitely longer than the 76. I had cut my chain for the 76 and now it is a link or two too short. I have the axles pushed all the way to the front and it is about a link short. Show I guess this messes up the gearing a bit. I'm sure it messes up the wheel base as well but this bike is just for the street so I doubt I'll notice the difference.

The 73 arm is much narrower close to the swing arm pivot giving a lot more clearance behind the rear sets than I had before.







Now that I have the new swing arm I will finally get the pipe fixed up. I didn't want to mess with it just in case there were issues with the swing arm.

[Andy]

Had some time today so I got the 73 swing arm on. This is what I learned.

The swing arm was 2mm too narrow at the swing arm pivot and needed spacers. Two washers under each dust cover did the trick.

The swing arm was 2mm too narrow at the rear. I took 2mm of the rear brake assembly at the top. There is a nice little lip there you can file/grind it down.

The 73 arm is definitely longer than the 76. I had cut my chain for the 76 and now it is a link or two too short. I have the axles pushed all the way to the front and it is about a link short. Show I guess this messes up the gearing a bit. I'm sure it messes up the wheel base as well but this bike is just for the street so I doubt I'll notice the difference.

The 73 arm is much narrower close to the swing arm pivot giving a lot more clearance behind the rear sets than I had before.







Now that I have the new swing arm I will finally get the pipe fixed up. I didn't want to mess with it just in case there were issues with the swing arm.

Hey,
Chains are identical 73/76 and i had no problems with my swap in that department,the difference in width at the front i did`nt notice either but the 76 has the adjustable fitting in the frame so why the spacers?
Rear spindle`s are different lengths between 73/76 and i think it`s the right hand spacer that is slightly narrower on the 73a....
Look`s good with the new arm
Regard`s
Andy

[rgvsp]

I'll revisit the chain this weekend and make sure I didn't pull some sort of tard move and cut the chain to short. I did measure the front of both arms and the 73 was 1.5-2mm narrower at the head. I did not want to adjust anything so the little washers in the dust covers seemed the easiest way to get the width back.