BGM Stator Failures

[Philipp]

As I told you, I would like to keep you updated about our bgm stator plate R&D we are doing at the moment.

To give you the complete story and share our findings this will be a little bit more comprehensive. First I have to admit that the statement for the HP (=high power) was a little bit optimistic with all the different ignition components out there. We have used the power rates of the stators as some manufacturers do. So we have stated the highest power output we have achieved. Somewhere we still think this is right. On the other hand there is a lot of misunderstanding on electrics. If you tune an engine and it gives 20 hp, then you should be ‘allowed’ to state it gives 20 hp, if you have dynoed it. But if you sell the engine and the purchaser over gears it so much that you can’t achieve this readings, you may get the problem to explain…

If we get back to the bgm stator, we have used the Vespa Cosa winding of the coils for the HP version. We have done a prototype using a contact breakers back plate and riveted the Cosa coils to it. Like Mark has invented it back in the 80’s with P-range coils. This was a straight conversion and we were able to power bulbs connection which summed up to 120 W.

The main goal with the bgm stator plate back then, was to have reliable setup with high quality field coil and Pickup for ultra high reliability. This was a serious problem back then and you may like to check the chapter of the ignitions in the Sticky manual for that. And with lots of positive feedback on that, I am convinced we did sort of right.

For the lightning power output the conversion from 6 V to 12 V is the first important step to increase the efficiency. With a 35 W headlight beam at 6 V current the Ampere readings are roughly 5.5-6 A at the beam. This high reading gives high thermical losses at the loom, switches, connectors and so on. This is the reason for dimming at low revs. With increasing revs the heat increases further. With 12 V current you can cut back the A readings to the half. The loom and connectors are not as highly loaded AND the thermical losses are only 25%. This leaves more energy for the bulbs itself.

For a high power output the coils should have thick wire to the maximum possible for the dimensions of the coil. Fixed in stone by the ignition design. The HP state plate does this. While we were more than satisfied with the bgm stators on our personal bikes, we take the forum critics very serious. We started to fiddle around to see what happens when the setups of the ignition systems were altered. We found the regulator have a massive effect on the performance.

We have looked into the DC conversion of the bikes as well. These ‘DC conversions’ use AC power output to run the main and rear light as well as the speedo bulb. While you use the DC power to run the horn/buzzer and the stop light. The problem WAS that you have to use a battery to have DC power saved for running at low revs. Despite of this, this gives top performance with no dimming of the lights when you use the horn or brake. Not a problem, when dimming is only recognized with the speedo bulb. But definitely frightening if you use the brakes running your Lambretta in the dark at mountains or in the rain on a motorway.
At the moment we are still testing different stator plate mods and have developed our own bgm regulator.

This gives AC and DC power output. We hope to have it produced later this year. But sadly these things are not as easy. The aim is to have the AC power output with a SENSE function. For this you have to do (on a first sight) strange connection from the power IN to the AC power out. But this connection is used to tell the regulator how much load is on the consumer. If the readings drop the regulator gives more for it. A bridge direct at the regulator is fine. This regulator should enable you to convert all bikes to DC, regardless if a AC or DC loom is used.

But back to the plot: We found that the magnetism of the flywheel has an important effect for the power output. Our fav stator for the testing (before we started) was a NOS old AF/Ducati flywheel. Sadly this gave the worst reading of all. Due bad storage it has lost nearly all its magnetism. Doh! We have different grades of magnetized flywheels for testing the stator plate now. We are considering this in our testing. We won’t state the power output in the future because of the given reasons. But it seems that a high power output reading isn’t the goal. Instead we are aiming to realize a solution that gives not max power output readings, but high output over the complete rev range. Especially low down the rev range. So like a good tuned engine!

For the stator plate test, I would like to ask the people who reported about the faulty stators to get in contact to me. I will give a free exchange plate. It would be nice to see one and use it for our tests.

I will keep you updated.

cheers philipp

[drunkmunkey6969]

Philipp......above all else, thank you for taking the time to write and post such a thorough and comprehensive response for everyone to read.

Cheers

Dan

[adriang]

Philipp......above all else, thank you for taking the time to write and post such a thorough and comprehensive response for everyone to read.

Cheers

Dan

I second that.. a very interesting read..

[Lamaddict]

Yes it was interesting but it doesn't seem as if they fully tested the product before they released it. Perhaps they should speak with the people in Tawian that are making the BGM gear and give them the clear scenario and the problems we enjoy with setting up Lambretta engines. I've tried various ignitions but my present engine has gone back to the SIL model which is the best I've had. More effort with the CDI and regulator make a difference IMO.

[MarkH]

I'm not really sure how you came to that conclusion.

The overwhelming majority of customers have something they like. Every product ever made has a rate of failure. Ian has stated MBs (though I am not sure if that is a true failure rate or simply a return rate), Philipp has stated Scooter Centers as being significantly less than MBs and I can tell you that ours is exactly zero. We had to replace one pickup on one stator that came from the very first batch. No returns and no complaints since. If you are not happy with the product than you should return it to the dealer. If the dealer won't help you than your complaint should really be with their service. In that case, take it up with the distributor.

The BGM products are constantly evolving and improving in an effort to make them as good as possible. There is a lot of hard work, effort and real dedication by some very good people going into these Lambretta products. I think BGM has shown that they are committed to producing the best product possible and are always willing to listen and respond to any and all feedback.

[Philipp]

Yes it was interesting but it doesn't seem as if they fully tested the product before they released it.

I can't see your point. I have told you how we tested and how the name came up. I have admitted that we are not very happy with the given name that states the power output as well.

MB once quoted the failure quote of the bgm stators. That was nearly 3 %. BUT that was not the failure quote, more the quote of the returns. As tests of these 'faulty' stators showed.

And only because we are looking into this issue and found improvements that can be done, you are slagging us off?

[Lamaddict]

Philipp, I'm expressing an opinion on an open forum not slagging you off. Some people aren't happy with your product and you have the right to defend it equally people have the right to question it. I hope you get the problems sorted with it.

[Diablo]

Its not the first time I've heard people say oh I've gone back to my original Indian set up. To imply these are more reliable than the BGM ones is laughable.
Indian ignitions may be ok on std type engines but I wouldn't think of putting one on a tuned bike without enough workshop time and parts to make it much more expensive than a BGM which I'd fit straight out of the box. Indian stators must have cost me more money in comebacks than any other part.
Every product has failures some companies deal with it better than others. I don't think you can fault Scootercenter here.

[J1MS]

Agree with that Al, Ive got at least 12 broken SIL stators, that I have taken off scooters in the last couple of years...

[corrado]

My combination of BGM stator and Ducati regulator blows all the bulbs. Changed back to SIL stator with same Ducati regulator and all is fine. BGM say my regulator is faulty. Discuss?