Bringing back an 80 Special

[motoman]

If you have a compressor, a soda blaster wold work really well on the rusted parts of the frame........quicker and more through than any wire brush.

[crazy steve]

Main issue at this time really stuck #2 piston.

I'm currently stripping the bike so I could pull the engine to better work on the stuck piston.

A spare engine came with the bike hoping the jugs can be used from it.
Has anyone replaced a sleeve only?
I was thinking of heating the cylinder with a torch and try to tap out the sleeve.
wish me luck

I was just reading a couple of posts in the archives about removing sleeves; it seems that if you heat the barrels to 450 degrees in an oven, they come right out. If you have a spare set of barrels/pistons (keeping everything 'matched' of course), a swap looks to be easy...

[rpgoerlich]

After letting them soak in PB, I used a ratchet strap on the cylinders of my 81H and drove out the pistons with a hammer handle. Only 1 & 4 were rusted halfway in.

[xs11lover]

Hey Rick, I have an 80 special motor I just took apart for a buddy to fix his trani. I have the pistons and sleeves that look to be good. You can have them if you want them.
GW

[Rickrod3]

Sounds good

Hey Rick, I have an 80 special motor I just took apart for a buddy to fix his trani. I have the pistons and sleeves that look to be good. You can have them if you want them.
GW

Did you take the sleeves out of the jugs?
I'm not too far can take a run up by you one weekend.

Rick

[Rickrod3]

Got the jugs off did some honing

Here was what #2 cylinder looked like before.

After




cylinder wall feels smooth to touch assuming it is in spec. can it be reused?

Also found cylinder head has some cracked fins.

[Rickrod3]

Engine questions

I have been doing some reading on these engines.
If I understand the differences correctly they are that the 78,79 years have a different piston crown and combustion chamber in the cylinder head.
All other parts jugs crank bottom end are the same.
Is this true?

If so; one option I have is to use pistons and head from a 78,79 engine.
It should work on an 80 engine shouldn't it?

Any down side to this?

Thanks in advance
Rick

[bikerphil]

Everything below the head except for the pistons is the same for all years 78-81. The early head has smaller valves than the late head. I know a member that has a 79 head on her 80 motor and pistons, and it works just fine. I haven't rode that bike, so I don't know how well it actually runs, but I'm pretty sure it raises the comp. ratio a bit. If you swap everything over, pistons, jugs, and head/cams, you should have no problems.

[cywelchjr]

Well, the ignition parts on the 81 are a good bit different, so you MIGHT need to swap some stuff, and the 80 if nothing has been done to it, the timing assy has non-removable screws holding it in place that must be drilled out if your going to tweak the timing or such, but that is indeed pretty much the only difference other than the ones outlined by phil.

[Rickrod3]

Carb jetting

I'm essentially turning this into a stock 78-79 motor. Should I go with the stock jets for a 78-79 carb?
I'm thinking differences in compression making the difference in carb jets.
I'm planning on stock pipes.

[bikerphil]

I'm essentially turning this into a stock 78-79 motor. Should I go with the stock jets for a 78-79 carb?
I'm thinking differences in compression making the difference in carb jets.
I'm planning on stock pipes.

Only if you are using early type carbs, use 137.5. If you are using late carbs, use the smaller mains, 115-120.

[natemoen]

To expand on what Phil is saying. There is a difference in the way the pilot jet gets its fuel between the 78-79 carbs and the later model carbs. So to start you need to jet according to what model carbs you have to start.

[crazy steve]

The timing curves on the vacuum/mechanical advances are different too; the early motors use more agressive curves. From the reading I've done in the archives, early cams should use early advances for best results...

[cywelchjr]

crazy steve has a good point, match timing curve to the cams and match jetting to the carbs and then work from there.

[Rickrod3]

The timing curves on the vacuum/mechanical advances are different too; the early motors use more agressive curves. From the reading I've done in the archives, early cams should use early advances for best results...

Hey Steve:

Thanks for pointing this out to me.
I checked the XSpart finder and I found the pick up coil assembly is the same on the E's F's and the SG. The Ignighter Unit assembly Black box is :
4RO 8230510-00 for the SG and 2H7 8230510-10-00 for the E's & F.

If I used one of the boxes from the E-F bikes would it give me the more agressive curve?


Thanks
Rick