GPz1100B2 – Completing the Rebuild

An end in sight

After a couple of years of delays and procrastination, the rebuild is in the final stages!

It is now January 2018, I’ve rolled the GPz1100 out and I’m determined to complete it over the next few weeks.

Over Christmas 2017 I reassembled the head which meant lapping the valves back in, checked and shimmed the cams and its now ready to install. This week I honed the cylinders and fitted rings, then dropped the head on. I had previously purchased a 76mm Cometic Head Gasket for it so it went in. Only trap for the unwary is to make sure the cam chain guide is fitted in with the rubber damper and alloy piece before putting the barrels  on.


At this point I decided I would fit new copper washers to the head bolts before I put the engine in the frame. I also need to chase up a cam cover bolt as one snapped when undoing the head some time back.

Since I don’t have these parts, I started on the wiring harness which is all mounted. First I hooked up a battery charger and began testing the power and ignition circuits. I need to to fabricate some connectors as the originals are damaged.

I also started on the blinkers, one needs replacing and a rear blinker wire is no good, so it needs repair. I also need to mount the regulator/rectifier somewhere and make a nice bracket for it.

When I removed the engine, the Oil,Neutral wires were damaged so I need to fix those. Just trying to source some coloured wire that matches pretty close and put some quality male bullet connectors onto them and cover them in plastic tubing.

Feb 3rd – Engine assembled, 90% of the wiring harness is fixed and I just need a few parts from the US to complete things. I will look at lowering the frame over the engine and then bolting it all together. More progress next weekend.

To sum the project up (and I will re-edit these sections once everything is completed), the project work has been done in the following steps:

  1. Frame Disassembly
  2. Engine Disassembly
  3. Frame Rebuild
  4. Engine Reassembly


Engine Parts

While the engine is installed I still need to get some cam half mood rubbers for it and on inspection I decided the intake rubbers should be replaced, so these are in transit to me. I also ordered a few body parts like front Blinkers.

I purchased a Cometic head gasket since its got bigger pistons than standard. These gasket are made from CFM-20.  CFM-20 is a perforated steel core with an elastomer surface that is ideal for head gaskets.  Allowing head to be drawn evenly across the gasket surface while providing maximum sealing characteristics when exposed to coolants and oils.

Bore Size Displacement Part Number
74mm 1060cc-1135cc C8019
76mm 1170cc-1200cc C8020
78mm 1230cc-1260cc C8021
80mm 1290cc-1325cc C8022
83mm 1385cc, 1425cc C8023

2 thoughts on “GPz1100B2 – Completing the Rebuild”

  1. excellent stuff mate, I’ve a B2 which is pretty horrible atm, I’ve had it a while and been collecting parts, I’m thinking about just getting it on the road rather than restoring it and then tackling it peice by peice when I have time , which probably means never ! ) really I’m just dying to use it but you site is an inspiration. I take it when you pulled the engine apart all was good, no need to do any bearings or check the crank ?


    • G’Day Paul,

      The bearings are needle rollers so they are pretty much indestructible as long as oil is fed to them and its reasonably clean.

      As for doing the resto of your bike, try this. Take 1 item and finish it.. if the frame is apart then start there and get the swingarm done at the same time (remove the bearings first). Then get the forks done, then the wheels.. just do one thing and bolt it to the bike.


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