1981 cbx project
Posted: Sun Apr 18, 2021 11:07 am
Last summer I bought myself a projectbike, a 1981 cbx 'prolink'.
The former owner had imported this bike from Switzerland in an unknown state. He had the engine touched up and rebuild the carbs.
He was planning on building a sort of 'cafe racer', so a few parts were not there anymore...
The engine didn't run. only tested the compression, which was between 100 and 120 PSI cold. It is fitted with a new starter motor and the upgraded Kawasaki dynamo.
First things to tackle:
complete brake rebuild (ss brake lines and fresh caliper seals) rear brake master cylinder was completely corroded so i used a GSXR 1000 07/08.
chain kit
new tires (old ones were from the other century)
original fairing
First reason for the bike not running/starting were the electronics. The wiring was stil original, but a new ignition switch was needed. This isn't a straight forward swap! Many thanks for this topic: viewtopic.php?f=21&t=11720
Another reason was the carbs. I serviced them with help of the booklet from Mike Nixon + the rebuild kit from Randakks. A few minor things were wrong + not working: the idle jet rubber plugs were installed, but only the 1979 models use it and the accelerator pump passages were clogged.
Before synchronizing I checked the valve clearances, then i found a broken camchain tensioner... The cam chain probably skipped a tooth, cranking the engine was hard. It took a while before I had a replacement (they are expensive).
To install the new tensioner the head has to come off. Good time to observe the valves and cylinders. What is your opinion about the boring, piston and valves from what you can see?
Well the bike start at this moment, but the clutch doesn't work. For what I believe there are 3 types of clutches? 6-pin clutch (1978/79), 9-pin clutch (1980) and the prolink (1981/82). I don't know the exact differences, but one is the length of the outer clutch guide. At some point someone swapped the prolink clutch for a 9-pin clutch but not the clutch guide. With the new guide the clutch works, it only rattles very much.
All assembled and complete this is how the bike looks at the moment:
My to do list for the moment:
- New oil hose (leek from the top near the cooler)
- Clutch rattle fix
- Suspension (progressive springs for the front and a new rear shock)
The former owner had imported this bike from Switzerland in an unknown state. He had the engine touched up and rebuild the carbs.
He was planning on building a sort of 'cafe racer', so a few parts were not there anymore...
The engine didn't run. only tested the compression, which was between 100 and 120 PSI cold. It is fitted with a new starter motor and the upgraded Kawasaki dynamo.
First things to tackle:
complete brake rebuild (ss brake lines and fresh caliper seals) rear brake master cylinder was completely corroded so i used a GSXR 1000 07/08.
chain kit
new tires (old ones were from the other century)
original fairing
First reason for the bike not running/starting were the electronics. The wiring was stil original, but a new ignition switch was needed. This isn't a straight forward swap! Many thanks for this topic: viewtopic.php?f=21&t=11720
Another reason was the carbs. I serviced them with help of the booklet from Mike Nixon + the rebuild kit from Randakks. A few minor things were wrong + not working: the idle jet rubber plugs were installed, but only the 1979 models use it and the accelerator pump passages were clogged.
Before synchronizing I checked the valve clearances, then i found a broken camchain tensioner... The cam chain probably skipped a tooth, cranking the engine was hard. It took a while before I had a replacement (they are expensive).
To install the new tensioner the head has to come off. Good time to observe the valves and cylinders. What is your opinion about the boring, piston and valves from what you can see?
Well the bike start at this moment, but the clutch doesn't work. For what I believe there are 3 types of clutches? 6-pin clutch (1978/79), 9-pin clutch (1980) and the prolink (1981/82). I don't know the exact differences, but one is the length of the outer clutch guide. At some point someone swapped the prolink clutch for a 9-pin clutch but not the clutch guide. With the new guide the clutch works, it only rattles very much.
All assembled and complete this is how the bike looks at the moment:
My to do list for the moment:
- New oil hose (leek from the top near the cooler)
- Clutch rattle fix
- Suspension (progressive springs for the front and a new rear shock)