Frame 350 1

Bike Problem Described

Hi Conor,
Very confusing situation here in Addis Abeba. If I put down as much of the facts as possible, I’m hoping you may be able to suggest a next step. I’m putting out a similar email to various contacts. The first section below describes the circumstances that led to the problem, the second describes my problem.
Bike: ’02 F650GS Dakar. 60,000 kms.

1. Events leading up to it.
On second day of difficult road across N Kenya desert, 2nd gear in deep gravel and rocks, red temp light comes on. Ride bit faster to try and cool engine, light goes off temporarily. But excessive speed for the conditions and I had a spill. Exhaust header pipe separated from silencer section (and sheered subframe bolt, but luckily had similar to replace). Reattached exhaust but no seal and exhaust gases escaping. Even with constant breaks, red temp light on then nearly permanently rest of day, except sections where could increase speed. (Couldn't stop - threat of Somali shifta or bandits, and limited water.) Made it to Ethiopian border town of Moyale (longest 200 kms I’ve ever ridden!).

Next day, higher altitude and sealed road, red temp light off, air cools it. However 100 kms north of Moyale, going up a hill, engine loses compression, and stops. Took out spark plug, water spurts out when turned over. A few truck rides later, arrived Addis Abeba. Took off cylinder head, and cylinder and saw damage. Hole burned in cylinder head near exhaust outlet, black discolouring part of rims, piston rings broken, gasket broken, some hoses show signs of heat damage.

2. The problem
Yesterday, replacement (2nd hand F650CS) cylinder, piston, cylinder head, water pump and seals, and new radiator put in (with new gaskets and hoses). Engine wasn’t taken out. New oil, coolant and spark plug. The engine started after a few attempts, and was running sweet and regular for three minutes. Opening and closing the throttle, gently at first, and then throttling up to 4,500 revs it cut out – no stuttering, no warning sounds, just an immediate stop. Wouldn’t start again.

Spark working, injector injecting, compression (engine turning over), swapped cpu box/EFI control unit with another F650 - no effect, and mine works on the other.

Then tried to put it into 1st gear. Discovered now, problem with gears. Can’t engage first. With gear lever held down, wheel turning, could feel ‘clack clack’ as it tries to engage. Will only find one gear (feels like 4th or 5th), then shifting down – only goes into (maybe false) neutral. Green neutral light stays on, even when in gear. Tried push starting bike to maybe ‘free up’ gears. Now no neutral (although green light still on).

- There has been no previous problem with gears.
- Very occasionally in last four months red temp light has come on, but for short time, then off.
- I serviced bike 2,000 kms before.
- Water pump seemed to be working (turns with wheel), as was fan.
- Usually don’t wait for fan to stop before ignition off.
- Unsure what caused overheating – suggested reasons are a combination of damaged radiator (fins squashed at back reduced area by about 25%), and after-market exhaust, which was then damaged, causing engine to run hotter.

So gears appear to have a problem, and the engine wont start. I’m not sure if the two are connected or separate problems. Any suggestions would be much appreciated, as am stuck on what is next step.
Regards, Hugh

Gearbox 530 1

Bike Problem Solved

Report to, an internet forum.

A week or so ago I described a predicament in Addis Ababa concerning rebuilt engine not starting, and having a problem with gears. The bike is now back on the road (ready for a test ride to Harar, a day away). The following may be of interest regarding the steps I took…

- Not finding any mechanic experienced in anything above 185cc to help, I approached Ultimate Motors on the Debre Zeit road and agreed with the workshop manager, Eskander Atomsa, helpful guy, to use his workshop. They happened to be pretty quiet, so I had young mechanic help me. With my laptop I was going by the manual and dvd – indispensable.

- First, as described in previous post, engine turning over but not starting. Went through all the checks again – fuel, sparkplug, air/ combustion – then rechecked timing. Found intake camshaft sprocket was loose, bolt not tightened, which presumably was the reason for the rebuilt engine to run for three minutes before suddenly stopping when timing was affected. Problem number one identified and sorted!

- Then took out engine (getting fairly familiar with the procedures now), and despite severe heat caused by original problem – see previous post – visually nothing awry in clutch (two plastic oil pump gears fine), and nothing apparently amiss in gearbox. BUT, spotted small bronze pin, about half an inch, on the loose. It should live in the (spring loaded) end of the Neutral ‘plug’ that is screwed in externally. I imagine this completes a circuit when gear is in Neutral, illuminating the green Neutral light on dash? The other end of this ‘plug’ is the terminal where the neutral light wire is attached on the right side of engine cover, just below the oil filter. What caused the pin to be dislodged I don’t know. Gears had been misaligned by, not quite a spanner in the works, but a tiny bronze pin.

- Now riding the bike two days, gears fine. Neutral light circuit broken by taking out that bronze pin, means I need to raise side stand and pull clutch lever when starting the engine.

So at this early stage of repaired bike (I don’t wish to tempt fate!), it looks like there wasn’t serious damage done to the gearbox despite 200 kms of desert riding overheating. I say again – I am in awe of the solidity of that Rotax engine!

Thanks again for the input.

Engine 300 1