Uneven timing?

[Dirty Ernie]

Is it possible that worn cam lobes on the distributer would caust the points to open at different gaps, causing the timing to fluctuate at uneven intervals causing the bike to idle and throttle at uneven speeds? It wants to speed up at steady throttle.
I've gone thru the carb (tear down, clean, adjust, replace) and intake connections and still have this problem. The advance springs aren't sticking or rubbing on the plate. I don't know what else to check. Anybody have a guess? Btw, it's a 73 sporty.

[newultraclassic]

Originally Posted by Dirty Ernie

Is it possible that worn cam lobes on the distributer would caust the points to open at different gaps, causing the timing to fluctuate at uneven intervals causing the bike to idle and throttle at uneven speeds? It wants to speed up at steady throttle.
I've gone thru the carb (tear down, clean, adjust, replace) and intake connections and still have this problem. The advance springs aren't sticking or rubbing on the plate. I don't know what else to check. Anybody have a guess? Btw, it's a 73 sporty.

Absolutely it could be a worn point cam. I've seen lots of them. With such a condition, it's not possible to get any sort of proper timing or performance.

The best fix would be to toss the point system and get a late-model electronic, either single or dual fire, depending upion whether you have the $$$ for replacement of the coil at the same time. There are literally dozens of them on the market. I would consider most of them to be OK, except for the ones that leave the weights in place for advance and simply change to a pointless design.

[Dirty Ernie]

Originally Posted by newultraclassic

Absolutely it could be a worn point cam. I've seen lots of them. With such a condition, it's not possible to get any sort of proper timing or performance.

The best fix would be to toss the point system and get a late-model electronic, either single or dual fire, depending upion whether you have the $$$ for replacement of the coil at the same time. There are literally dozens of them on the market. I would consider most of them to be OK, except fo rthe ones that leave the weights in place for advance and simply change to a pointless design.

Yap, that was gonna be my first priority, to convert the points to electronic. Problem being, spent the family fortune to buy this fixer-upper. Didn't leave much money for renovations. Just trying to muddle thru for now anyway. Thanks for the help ultra, you seem to be the go-to guy here. I wish I lived across the street from ya. I would nag ya to death for help.

[springer-]

On the older bikes I am not against using the fly weight advance system. But definately get rid of the points. The Twin Power Electronic ignition replaces the points and retains the advance weights. It can be used single or dual fire and can use your existing coil. It can then be upgraded to single fire later if you desire. Don't use the Dyna "S" ignition, it is the worst one made.

As for points and the timing accuracy, even with a brand new set of points and new point cam, the timing can vary +/- 10 degrees either way and from cylinder to cylinder. In other words, points are junk when they are in perfect condition and only go down hill from there.

[Dirty Ernie]

I agree with your point springer. I can't wait to get some electronics on this bike. Can I still use this distributer with worn cam lobes when I switch to electronic ignition?

[springer-]

I wasn't thinking about it being a distributor, but the twin power ignition is available in a distributor form. I didn't think the 73 sporty had a distributor??? I thought it was in the cam cover. I guess I will have to look that one up. But either way it is available.

The cam lobes you are refering to for the points will be removed with the addition of any electronic ignition.

[Dirty Ernie]

[QUOTE=springer-]I wasn't thinking about it being a distributor, but the twin power ignition is available in a distributor form. I didn't think the 73 sporty had a distributor??? I thought it was in the cam cover.

You're right springer. It doesn't have a distributer per se. I only reffered to it as a distributer for descriptive purposes.