Bogging and dying at high revs

[karlos4]

Hi All,


Having a bit trouble with my 1990 400, I know the battery wont hold it charge but im assuming that isnt the problem, when i give it any over 4000rpm when the bikes warmed up it bogs and dies like its starving of fuel but it cant be that as its fine when cold! coming home from work today i got on a strech took it to about 70mph and it started bogging, till i slowed, when i reached the junction and started shifting down it just died, then it seemed like no power was getting to the battery at all, i left it for a while then tried again and all i got was the starter motor clicking (it wouldnt even click when hot) i got a mate to come with a set of jump leads and it fired up fine and i rode home. anybody any ideas? possible electrical fault? (note the bike didnt get excessively hot when riding, temp gage was about a 3rd of the way up). could it possibly be the coils?

any help greatly appreciated,
karl

[Variablevalves suck]

Sounds like your reg/rec is not working so battery is shot.

[karlos4]

im no electricals expert so correct me if im wrong, but can it tell this by.. connecting multimeter over battery terminals and revving the bike (this should give around 14v?) if it doesnt its the reg/rec? might sound daft but why does this only happen whent he bikes warmed?

cheers

[Variablevalves suck]

You get all sorts of weird stuff going on once you get heat into stuff.
Could be something else but first thing to check.
Lights on full hold revs at 5000 and you should get about 14.5 v.
Anything less than 13.5v and its duff.

[karlos4]

cheers, il give it a bash when i get in from work tomorrow and come back with the results!

[karlos4]

Right, got hold of a multimeter used bike for work today and kept the revs low, got home battery is reading 12.7 when not running and 15.6 at 5k rpm with the lights on. the strange thing is when it started to bog and die it flattened the battery? yet the battery isnt bad, could it be the alternator thats doing this? it seems strange how its only killing the battery at higher revs!

Karl

[gixxer400]

Charging voltage should not exceed 14.5V. It would appear you rectifier / regulator is faulty, and is breaking down. You may have to replace your battery if it is fried!