81 vs. 82 GS1100E Engine Diff's

[staschman]

Considering an 81 GS1100E motor to put in my '82 GS1100E frame and body due to bad crank bearing on current '82 motor.

If it works out, I hope to take the '81 motor, drop it in, hook up existing connections and run with it.

I know the bolt placement in the valve cover is probably different, but are there any other differences? IE: motor mounts, clutch, starter clutch, starter, electrics, etc.

[Hap Call]

Considering an 81 GS1100E motor to put in my '82 GS1100E frame and body due to bad crank bearing on current '82 motor.

If it works out, I hope to take the '81 motor, drop it in, hook up existing connections and run with it.

I know the bolt placement in the valve cover is probably different, but are there any other differences? IE: motor mounts, clutch, starter clutch, starter, electrics, etc.

1. The '81 motor has a mechanical tach and the '82 has an electronic if I'm not mistaken.

2. The '81 crank is not welded and sometime in '82 they began welding the cranks - some '82's have 'em but other do not.

3. The cam end covers are different but that is only cosmetic.

4. I believe the cams have a different grind, I.E. different lift and duration.

5. I believe there is a difference in piston pin size (18mm vs 20mm, I think), rod length, and piston design due to the longer rods and bigger piston pins - stroke remains the same.

6. The left hand crankshaft end has different part numbers (12261-49203 for the '81 and 12261-49302 for the '82)..I'm not sure if that indicates a different taper on the shaft or what. I do know that at one point they (Suzuki) eliminated an oil gally that was drilled through the left hand crankshaft to increase crank strength. The rotor has the same part number (31402-49310) for both years which indicates the taper did not change.

Hap

[staschman]

Wow, thanks Hap Call,

Thats a lot of good info.

Regarding the tach hookup on my current '82, it is a mechanical fitting on the motor itself, much like the speedo cable hooks in at the axle.

Is that how the '81 is too?

[RJ]

Tach hookups were mechanical until the 1150 in '84. Piston pins were 18mm until '84 as well.

[jpaul]

The choke setup is different between the 81 and 82 models. The 81 is a knob in the steering head, and the 82 has a lever on the handlebar. You'd need to swap the choke linkage on the carbs. The airboxes are a little different, and the main jet is different between the 81 & 82's.

[Hap Call]

Tach hookups were mechanical until the 1150 in '84. Piston pins were 18mm until '84 as well.

Thanks for the clarifications RJ.

Hap

[minutemen]

Cams are the same until 83. The cam sprocket bolts are different beginning in 82.

[Mysuzyq]

Not to hijack the thread, but are 1150 cams any different in lift/duration than the '82 1100E (is there any performance benefit to this mod)..... I hear a couple different opinions on this....I know the 1150 has the electronic tach.

Tony.