Old Ultra fired up easily and good response from throttle. Took it for a 2 mile run. Started her up the next day and immediately it was misfiring,backfiring and idling very rough. Checked the Ultima timing and it seemed ok. I noticed the day before that the Voltage Regulator was very hot after the 2 mile run. I foolishly forgot to check the voltage meter to see if there was the usual 12-14 volts on the gauge when riding. The recent rebuild included .... Evo 27 cam and Torrinton bearing. Adjustable Lifters. Must say that the Ultra was running beautifully during the short run. Any ideas anyone? Any suggestions much appreciated.

 

Carb or ignition. Check the voltage at idle, as if it is too low, the ignition can not function properly. Piece of trash in the carb? Float stuck?

 

Thanks Doc. will check these tomorrow.
Meant to say... The voltage reading was low when idling/running and misfiring. Also notice that the battery doesnt hold its charge ie, after shutting off engine and trying to restart the battery is usually unable to turn engine over again.

 

Well, a quick run through the charging system stickie is a good place to start. Start with charging the battery overnight. Then just the voltage at the battery off, running at idle, running at 2K RPM, say, and see if that is all OK. If it is, no need to go further.

 

Thanks for reply Doc.
We managed to find the fault re. poor idling,backfiring etc. The inlet manifold
was at a slight angle. This was allowing air to enter. Sorted, so running well and idling. The Voltage sits at 10 when engine at 2k revs then goes up to 11-12. Charge from motor to Voltage regulator is good. Appears to be Voltage
Regulator problem but not100% certain, Have tried another Voltage Regulator but no change. Where does the very long wire from the V. Regulator go to?
In the Factory Manual it looks like it goes to 30 amp circuit breaker.
As stated previously the Voltage Regulator body was very hot.

 

The regulator wire goes to the main breaker under the seat.

Kinda sounds like you have a short. Put an ammeter in series with the battery negative, then turn the ignition on (not running, just the ignition in the On position) and see how much current is flowing. I would GUESTIMATE that it should be around 7-ish amps, maybe 10 at most with the headlight on and brakes off. If it's 15 or 20 or more, you have a short or near short somewhere.

 

Fixed.!!! New Voltage Regulator solved problem. Backfiring and rough idling/running also fixed. Motor sounds sweet. Only task left is to fit a "Badlands" Turn Signal Module which should arrive Monday coming.
It has been 2 long years since rebuild was started due to rust at Swinging Arm. Hope to catch some of the UK summer before it disappears.!
Pics to follow soon. Many thanks to all members for their help and advice over the 2 years. without you the rebuild would never have been completed.Bungo

 

Pictures of you getting it out of the house?

 

Sorry Beemervet but I didnt even think about taking pics.
Wish I had now that you mention it. As there was only 2 of us handling the bike and the gap between the Batwing and the 4 doors (+ 4 steps down) was about the size of a *Midgies dic- it would have been very difficult.
*Midge. A very,very small flying/biting insect which is common in Scotland especially after hot then damp weather. It bites and can cause great irritation & itching. Sorry,should have added....only the Female bites. Beware if you ever visit Scotland UK.

 

Them ******* are why I used to visit Scotland in the winter...that and it's really difficult trying to get an ice axe to hold in running water...