My Megabusa - trials & tribulations [update on Page 4]
Posted: Wed Jun 26, 2019 5:42 pm
Thought I'd start a blog-style topic documenting the latest round of 'issues' with my Westfield Megabusa turbo and my cack-handed attempts to fix them.
The 2019 Eurotour to the French Alps a few weeks ago was truly excellent, but my car returned with several issues:
- battery not charging - charging system outputs ~13.2v when cold, but drops away to nothing when engine is hot.
- diff leaking - oil leak coming from pinion oil seal at diff nose.
- 6th gear AWOL - half-way through the tour I went for an unremarkable gear-change from 5th to 6th and just got a lot of noise, banging and knocking... but no drive. 6th gear had disappeared has remained completely elusive since.
So, considering I know almost nothing about bike engines, gearboxes and charging systems, I decided to get my hands dirty and give it go.
First job - while engine is still running - is to diagnose the non-charging battery...
I didn't really know this before, but motorcycles have a less integrated charging system than cars. The bike has the generator part of the system inside the engine. The rotating part of the generator is driven by the engine, and the fixed part is called the 'stator'. The stator generates AC voltage on 3 phases (3 wires). These exit the engine and provide a separate component, the Regulator/Rectifier, with AC voltage which it converts to ~14v DC output that can charge the battery.
So there are two components that could have failed; the Stator or the Regulator/Rectifier.
Now, when I was having issues in France, the garage there did a few multimeter tests and declared that the Stator was FUBAR.
Obviously, I wanted to try and confirm this myself. With the help of a Hayabusa Service Manual [thanks Google] and a multimeter, I went about testing the Rectifier which seemed to pass all the resistance/diode tests - good stuff.
Next to test the Stator - I did resistance test between each of the three phases and these seemed a little higher than spec but not much. Then to test AC voltage output of each of the 3 phases... first two were OK at 20V at idle but third phase showing only 4V. You are supposed to test this at 5k revs and see around 70V on each phase, but to be honest that would have been too noisy and I was happy to accept the low reading on one phase at idle and the opinion of the garage in France, and declare the Stator 'Dead'.
Now the fun starts! The engine has to come out to replace the Stator and to diagnose the gearbox issue...
Car lifted on to stands and ramps. Oil and coolant drained. Front body panels removed... really easy with the detachable side panels!
Chassis brace and turbo has to be removed, after disconnecting the turbo oil supply and oil drain hoses.
Opted to keep the exhaust manifold attached. It's a tight fit to top chassis rail, but I think engine will come out with it attached.
Turbo unit doesn't have come apart to remove it.
Lots of wiring to remove on this side. Unfortunately the main loom had been fed between engine and engine cradle and so the front loom had to stripped back to the bulkhead. I opted to snip the lighting wiring and will wire up connectors when I put it back in.
Dry sump tank removed to allow more access, and to allow me to drain it properly and clean it out.
At the back of the engine the prop shaft was unbolted as well as disconnecting oil scavenge pump feed and the brake slave cylinder connection.
At the front of the engine, the oil inlet from Dry sump tank was disconnected as well as oil pressure gauge hose and oil pressure warning light switch wire.
Engine is mounted to an upper engine cradle which is bolted to the top of the chassis, as well as a smaller lower engine cradle which is bolted to the lower chassis. The engine was unbolted from the cradle which stays in the car. However, the upper cradle should be removed with the engine so that was unbolted from the chassis without drama.
Engine lifted with inlet manifold and plenum still in place. Lifting straps around the upper engine cradle and engine mounts. Came out pretty easy.
Engine on the bench, with upper engine cradle still attached.
Empty space. Needs a clean!
Engine on the bench. Now to make something to be able to mount this thing to a Clarke engine stand.
More to come!
The 2019 Eurotour to the French Alps a few weeks ago was truly excellent, but my car returned with several issues:
- battery not charging - charging system outputs ~13.2v when cold, but drops away to nothing when engine is hot.
- diff leaking - oil leak coming from pinion oil seal at diff nose.
- 6th gear AWOL - half-way through the tour I went for an unremarkable gear-change from 5th to 6th and just got a lot of noise, banging and knocking... but no drive. 6th gear had disappeared has remained completely elusive since.
So, considering I know almost nothing about bike engines, gearboxes and charging systems, I decided to get my hands dirty and give it go.
First job - while engine is still running - is to diagnose the non-charging battery...
I didn't really know this before, but motorcycles have a less integrated charging system than cars. The bike has the generator part of the system inside the engine. The rotating part of the generator is driven by the engine, and the fixed part is called the 'stator'. The stator generates AC voltage on 3 phases (3 wires). These exit the engine and provide a separate component, the Regulator/Rectifier, with AC voltage which it converts to ~14v DC output that can charge the battery.
So there are two components that could have failed; the Stator or the Regulator/Rectifier.
Now, when I was having issues in France, the garage there did a few multimeter tests and declared that the Stator was FUBAR.
Obviously, I wanted to try and confirm this myself. With the help of a Hayabusa Service Manual [thanks Google] and a multimeter, I went about testing the Rectifier which seemed to pass all the resistance/diode tests - good stuff.
Next to test the Stator - I did resistance test between each of the three phases and these seemed a little higher than spec but not much. Then to test AC voltage output of each of the 3 phases... first two were OK at 20V at idle but third phase showing only 4V. You are supposed to test this at 5k revs and see around 70V on each phase, but to be honest that would have been too noisy and I was happy to accept the low reading on one phase at idle and the opinion of the garage in France, and declare the Stator 'Dead'.
Now the fun starts! The engine has to come out to replace the Stator and to diagnose the gearbox issue...
Car lifted on to stands and ramps. Oil and coolant drained. Front body panels removed... really easy with the detachable side panels!
Chassis brace and turbo has to be removed, after disconnecting the turbo oil supply and oil drain hoses.
Opted to keep the exhaust manifold attached. It's a tight fit to top chassis rail, but I think engine will come out with it attached.
Turbo unit doesn't have come apart to remove it.
Lots of wiring to remove on this side. Unfortunately the main loom had been fed between engine and engine cradle and so the front loom had to stripped back to the bulkhead. I opted to snip the lighting wiring and will wire up connectors when I put it back in.
Dry sump tank removed to allow more access, and to allow me to drain it properly and clean it out.
At the back of the engine the prop shaft was unbolted as well as disconnecting oil scavenge pump feed and the brake slave cylinder connection.
At the front of the engine, the oil inlet from Dry sump tank was disconnected as well as oil pressure gauge hose and oil pressure warning light switch wire.
Engine is mounted to an upper engine cradle which is bolted to the top of the chassis, as well as a smaller lower engine cradle which is bolted to the lower chassis. The engine was unbolted from the cradle which stays in the car. However, the upper cradle should be removed with the engine so that was unbolted from the chassis without drama.
Engine lifted with inlet manifold and plenum still in place. Lifting straps around the upper engine cradle and engine mounts. Came out pretty easy.
Engine on the bench, with upper engine cradle still attached.
Empty space. Needs a clean!
Engine on the bench. Now to make something to be able to mount this thing to a Clarke engine stand.
More to come!