Triumphrat

Blownfuse · 06-10-2005

THe bonneville wants to stall while i accelerate. It will idle, when i apply gas it boggs down or stalls. Also the battery seems to be draining while this happens. very hit or miss it seems to happen after a ride of atleast 30 minutes.
any ideas? thanks

crazypierre · 06-10-2005

Blownfuse
I will bow to the others' greater experience and this is probably not what I experienced, but worth checking anyway-I had a similar problem on my Bonnie and it turned out to be a worn ignition key switch. Over the years the mechanism had become worn and it was shorting out the electrics and causing it to try to die and stall. If I remember rightly it got worst after 15-20 mins perhaps as the electrics got hotter? I thought it was fuel/carbs/timing but put a new ignition switch in and hey presto-solved the problem.
Pete

Doublespin · 06-10-2005

Do you have points or EI? and what makes you say the battery is draining? I presume you have pleny of fuel available at this point.

Blownfuse · 06-10-2005

Maybe the battery seems low to me because I start it a few times right in a row. The llights are dim.
Also the bike will stall when in idle if i swith to high beam. I just noticed this. It had not done that before
The tank appears to be just under half. It has the small 2.25 gallon tank.

jimballard · 06-10-2005

O.K. try something silly to placate me. When it's in it's stalling mode, see if the zener diode is really hot. I had the battery on my '70 give up the ghost and it acted pretty much like what you're going through. The battery accepted little or no charge from the alternator and the excess voltage was absorbed by the diode. I'm surprised that it was still good after all that. Also, is the alternator and/or the rectifier working properly?

Just a couple of thoughts: Jim

okiecityflash · 06-11-2005

I had a problem 1 mo. ago. when I turned the headlights on at idle it died. It ran at 3grand lights on, at idle it died. Charging right, Battery shot. R&R'd battery, everything cool. Might check alt. output & batt. first. Good luck.

OzBloke · 06-11-2005

Blownfuse,
Good advice from Jim B. I'd be looking at a faulty Zener diode, changing it's threshold voltage under heated conditions. Also, if you've got the original Selenium rectifier, I'd recommend replacing it with silicon bridge rectifier (15-25 Amp from any electronics parts store) - mount on a L-shape piece of metal as a heatsink.

Let us know how you get on.

Doublespin · 06-11-2005

You didn't mention whether you had electronic ignition. Boyer's are pretty fussy at low volts and I guess that they would perform better at low revs when the voltage is critical. I think that they will not work at around 9v or lower. If you can grab or borrow a meter this would be useful and may also show if you have a zener problem. Don't disconnect the zener if you have EI though or you may blow the box.

Blownfuse · 06-11-2005

I have points.
Is there an easy way to check alternator output at Batt.
I haven't checked the book yet.
I started it tonight and it was fine. i went 50 feet down the road: slowed and it stalled.
Haven't tried other suggestions yet later this week.
thanks

Doublespin · 06-12-2005

To check alternator output at the battery you can get a good idea if you have a voltmeter. When you rev the bike to about 3000 revs it will go up to about 14.5 volts. Switch the headlight on and if the alternator is working you will be able to bring the volts up to 13.5 to 14v when revving to about 3000. On tickover the voltage will fall back to about 12v unless the battery is discharged or knackered when it will go lower.
You haven't mentioned how the engine dies does it misfire or tend to backfire when increasing the revs, if so check the condensors which effectively go across your points if these are open circuit then increasing revs just causes the engine to misfire. You could look at the points with the cover off and see if they are sparking a lot - this shouldn't happen if the condensers are good.
If the engine just dies then you may have a main jet /fuel blockage - check your filters and fuel lines.
Will it rev up whilst in neutral i.e. not under load?