1946 WL Runs Rough After Warm Up

[teambrownracing]

I have a 1946 WL. It has a new overhaul on the engine and a new carburator. Since the overhaul the motorcycle has been very hard to start and once running it starts running rough after about 5 minutes of warm up. Any ideas?

[T. Cotten]

Teambrownracing!

Please bubble-test the manifold assembly, even if it is 'new':
http://virtualindian.org/11techleaktest.html

When you get no bubbles, then we can go on to other things.

Good luck!

....Cotten

[teambrownracing]

Thanks for the idea. I would not have thought of this. I'll let you know how it turns out.
TBR

[teambrownracing]

You were correct. The manifold failed the bubble test. I am going to be out of pocket for a week but when I return I will remove the intake manifold and see if I can resolve the leak. In the meantime, thank you again for the assistance.
TBR

[teambrownracing]

I have some additional questions. Are the brass intake manifold seals reusable? Do you have to loosen the pots at the base to achieve good intake manifold alignment? Any help you can give with these questions would be appreciated.
TBR

[T. Cotten]

I have some additional questions. Are the brass intake manifold seals reusable? Do you have to loosen the pots at the base to achieve good intake manifold alignment? Any help you can give with these questions would be appreciated.
TBR

TBR!

Please do not loosen the base nuts.

Brass was all the founders had that worked at all, but you may wish to investigate more modern approaches.
Annealing them cherry red for a while was a bandaid for many, or so I've read.

And please inspect quite closely, both seal and nipple, where they butt against each other.
If the nipples pass the bubble-test, the rest is easy.

....Cotten

[teambrownracing]

Thanks again for your input.
TBR

[teambrownracing]

Cotton, I am reasonably sure there are now no manifold leaks. The bike now starts on a single kick and it will run at idle but when I put on a little throttle it starts to miss fire and sputter and I do not believe it is making reasonable power. I have followed the manual instructions for initial carburetor settings and it seems to idle ok. I have new points and condenser, the plugs are practically new, it is timed according to instructions in the manual. I am a little lost with reference on what to do next. I have a carburetor that was overhauled by the guys at at 45's Unlimited. It has a new style "rubber ducky" float. I'm considering taking the carburetor apart to determine if there may be a blocked passage or a chance that the float may be misadjusted or hanging up. Any other ideas?
TBR

[rudy]

I had the same problem,
I did a compression test and found a valve sticking open, still running like crap.i tried
different carburetor's , on a whim well test riding and frustrated i started backing out the high
speed screw to were it was not even in the same zip code from the books starting point.
Bike runs like a sewing machine now.
good luck with yours.
Rudy

[Paps]

Are you trying to throttle up with the timer in the retarded position ?

[T. Cotten]

Cotton, I am reasonably sure there are now no manifold leaks. The bike now starts on a single kick and it will run at idle but when I put on a little throttle it starts to miss fire and sputter and I do not believe it is making reasonable power. I have followed the manual instructions for initial carburetor settings and it seems to idle ok. I have new points and condenser, the plugs are practically new, it is timed according to instructions in the manual. I am a little lost with reference on what to do next. I have a carburetor that was overhauled by the guys at at 45's Unlimited. It has a new style "rubber ducky" float. I'm considering taking the carburetor apart to determine if there may be a blocked passage or a chance that the float may be misadjusted or hanging up. Any other ideas?
TBR

"Reasonably" ain't good enough, TBR!

You want it absolute, or it will just confuse tuning, even if the carb is perfect.
(Especially,.. .. . if the carb is perfect!)

You can't wish away a vacuum leak. The tiny ones are most diabolical.

...Cotten
PS: Your Ducky should do fine, depending upon your fuels...

[pisten-bully]

All good ideas to check for sure, so I'll throw in one more "maybe", and that is in the Indian Rider's Instruction book (dunno what HD tells you) the initial settings they give you for the carburetor are very rich, so you said it starts and idles...let it warm up and start leaning out the carburetor to see if your problem gets better or goes away!