Timing advance springs

I tried to set the timing on my bike tonight. When idling the mark lines up great but I lost all top end power. I watched it with the light as I held a fairly steady higher rpm and you could see it changing bad. The spring on one side looks tighter than the other. With 70,000 miles on it I figure the springs have sprung and need replacing. What's the best thing to do? Should I go to the dealership and get a set of springs or replace the whole unit with an aftermaket setup?

I'm not sure if your '98 police model 1000 has a mechanical advance. That would be weird. Most late model machines are all electronic. But in case it does: dig out your shop manual for the specifics. Test your timing at idle like you did, there should be a second timing mark that lines up when the ignition is at full advance. If its not lining up then the mechanical advance needs to be removed, cleaned and lubed (not a big deal). If this doesn't fix the problem, then I think the only option is to replace it as a unit. Or convert to an after market electronic but that would be pricey.

hope this helps...Sam

pidaster wrote:

I tried to set the timing on my bike tonight. When idling the mark lines up great but I lost all top end power. I watched it with the light as I held a fairly steady higher rpm and you could see it changing bad. The spring on one side looks tighter than the other. With 70,000 miles on it I figure the springs have sprung and need replacing. What's the best thing to do? Should I go to the dealership and get a set of springs or replace the whole unit with an aftermaket setup?

Spring Tech 101...

Three kinds of springs... I AM SORRY I DON'T REMEMBER THEIR OFFICIAL HARDWARE STORE NAMES!

The first is the type that only pulls open. The second is the one that only pulls closed and the third is the both way type spring.

IF you pull of a spring from your mechanical advance and pull it out, it will be RUINED. It is a close only spring... I THINK they call these compression springs in the hardware. I know because I pulled a couple OUTWARDS trying to get off a rusted mechanical advance center piece. Needless to say, the springs were ruined. I did find some compression springs of about the same gauge wire at the hardware. Some work with some pliers and I made the ends hooked at the same length as the originals and they worked OK but not quite as well as the orignal type springs.

You will very likely not find springs sold as separate parts from a dealer. I suggest, you just replace your mechanical advance... clean the new one good; removing all rust and lube it up nice and you will be as good as new. It is very likely that your OEM springs are tired on your cop bike after 70K miles. I always keep a spare mechanical advance or two in the shop just for this reason. One for use with points or a Dyna S and another "fixed position" advance that only has the full set of timing marks for the 1/4 cylinder (they generally have the TDC mark for 2/3 only. They are on eBay all the time.

Want to know something about springs besides your basic F=-kX from first year physics? Have a look at this site on spring design and making your own springs .

So the only way that I've found to replace the springs is to purchase a governor kit. Depending on where I get it, price ranges from $80-$150. I was told that it is simply a crankshaft counter weight but I don't understand that part at all. The only local shop (other than dealer) is unwilling to help me. As soon as he realizes it is a cop bike he'll tell me he can't get it. He's just a buttwiper though. Any other ideas? I found some older units on ebay that are NOS that will not fit but maybe the springs will.

There is a possible option, but it involves some simple modification

Loudhvx has designed an ignitor that you can build yourself for ~$45 using HEI modules with the built in advance locked out. He expressed an interest in designing one using the HEI's built in electronic advance if someone wanted to lockout the stock mechanical advance by welding it (Take the springs and weights off and spot weld the advancer to the shaft).

If he doesn't see this thread and post here, you might send him a PM and ask him.

The governor/advance assembly is $75.04, for a new one, from Ronayers.com. Plus $8 shipping.

It's possible to learn enough to make your own springs from the site I linked earlier.

You might be able to retemper your old springs if they are not corroded.

I am going to try and re-work my springs but if it doesn't look good I'll order the new one from Ronayers.com. Thanks for the link.