1986 R80 wont start after timing chain job

[gog]

hi, I have a bit of a problem and would appreciate any pointers.

I replaced the timing chain and reassembled everything as it was before. bike was running fine before the job started. got it all buttoned back up again, checked it was in neutral, hit the starter and just a loud metallic click (from what I assume is the starter). won't turn the engine at all, not even a tiny movement. the bean can is in the same position as it was when removed, front cover is off. the battery was fine a week ago when disconnected and is less than a year old.

timing marks on crank and cam line up at 6 and 12. engine turns fully moving the back wheel.

any ideas? I'm stumped.

 

[david a hall]

Is it on the right stroke?

 

[Padmei]

Wires correct on the starter motor? Inmate on adv rider had a similar prob recently. They use a black as a positive.

http://advrider.com/forums/showthread.php?t=962056

 

[gog]

hi david. the wheel was turned several times to check timing marks etc whilst the bike was off. it may well be on a different stroke to when it last ran. to be honest I wasn't aware it made any difference, as long as neither the cam or crank moved whilst the chain was off. can you explain a bit more? I'm still rather new to these.

 

[gog]

Padmei, i didnt change any of the wires on the starter, simply plugged it back in as it was before. as I remember, there's a sheath coming in to the housing from top, with a black wire (starter), a blue to the back of diode board, brown to LHS and black to RHS on alternator.

 

[Smug]

Bad battery connection?

Flat battery?

Starter?

 

[Beemerboff]

That click is the solenoid trying to engage, so you have some power at the starter , but not enough to either fully engage the solenoid or to turn the motor over.

Could just be the battery, earth or starter connectionless, be careful with the starter as some have bronze connections which ere easily stripped, so star washers are a good idea here, and elsewhere.

Or your battery could just be dying under load - some modern batteries fail this way, perfect one day dead under load the next, although they still show full volts on a voltmeter.

 

[duckspeed]

Sounds more like something wrong with valve timing
Take the front cover off and make sure the engine turns using the front pulley bolt.
Doing it at the wheel through the gearbox and with the plugs in gives no feel or good feedback.
Why would there be a starter/battery fault if all was OK before the job?



Sent using witchcraft

 

[cookie]

sounds like the battery's flat or got a bad connection to me.

 

[gog]

The front engine cover is still off, so I will remove both rocker covers and turn the engine over with the rotor bolt. Is there anything particularly I should be watching for?

The timing marks on the two sprockets are lined up perfectly at 6 and 12, facing each other

The first time I installed the chain the camshaft was rotated one tooth too far clockwise, so I took it off again and moved the camshaft sprocket back a tooth using a flat tool in the bean can keyway.

The crankshaft sprocket does have another timing mark, at 12 directly opposite the one at 6 in the diagram. I am sure that there is no way that timing could be 180 degrees out, nothing was moved more than a sprocket tooth width whilst the timing chain was off.

The mention of valve timing has me concerned. I dont want to risk wrecking internals by starting (or attempting to start) an engine which is way out of timing alignment.

Sounds more like something wrong with valve timing
Take the front cover off and make sure the engine turns using the front pulley bolt.
Doing it at the wheel through the gearbox and with the plugs in gives no feel or good feedback.
Why would there be a starter/battery fault if all was OK before the job?



Sent using witchcraft

 

[gog]

Thanks for the replies. Seems the place to start tonight for me is going over the electric system, making sure that I have plugged everything in, tightened the battery terminal connections and checking voltages.

 

[Rob Farmer]

A common problem is that the bean can doesn't go into the slots on the cam properly.

Of course the starter may not be doing anything because a valve is now embedded into the top of the piston

Seriously

Have you put the black wire that threads through the back of the timing case back onto the starter motor connection? The clunk you are hearing may just be the relay under the tank.

 

[gog]

Thanks Rob. I did put the black wire back through the case on to what FELT like its spade connector, but I will double check its on there right.

The tank is off and the clunk sound certainly sounds to be coming from under the starter motor cover, im assuming its the solenoid.

If there were some valve-piston shennanigans, would I be able to tell from cranking the engine with the rotor bolt, or is it time to remove the heads? I would like to be able to tell if I have cocked up the timing severely before I try and start it again. Im leaning towards it being electrical gremlins, but would rather rule out internal damage just to be safe.

 

[duckspeed]

Does the engine turn smoothly at the crank pulley?
If it doesn't you have done something wrong in the timing



Sent using witchcraft

 

[Rob Farmer]

Thanks Rob. I did put the black wire back through the case on to what FELT like its spade connector, but I will double check its on there right.

The tank is off and the clunk sound certainly sounds to be coming from under the starter motor cover, im assuming its the solenoid.

If there were some valve-piston shennanigans, would I be able to tell from cranking the engine with the rotor bolt, or is it time to remove the heads? I would like to be able to tell if I have cocked up the timing severely before I try and start it again. Im leaning towards it being electrical gremlins, but would rather rule out internal damage just to be safe.

If it is the starter clunking then you must have put the wire on correctly in which case it's either the starter or the main feed cable to it. You shouldn't need to take the heads off, If you could turn the engine with the back wheel it must be about right.

 

[gog]

When jiggling wires on removal, the one the red arrow is pointing to that connects to the spade on the RHS of the diode board cracked. It appears just to be a brittle sheath though, as theres a red wire underneath that looked fine.

The little black wire at the top is the one I connected to the starter.

 

[Rob Farmer]

That looks ok.

 

[gog]

problem sorted. turns out it was a bad connection to battery +ve. bit of a clean and sandpaper and fired right up.

thanks for the advice, much appreciated.

 

[Smug]

Always check the simple things first