danny_galaga

That's getting a bit academic. I'm not building a 11kv transmission tower! Everyone uses copper cables for starter motors. so will I. Lucas sometimes used aluminium for field windings in their starters. The copper tag of the brushes were spot welded on. If you had to replace them, normally you would cut off the brush, leaving a bit of the copper tag behind. Then bind the new brush on with a single stand of copper wire and solder. One place I worked at did a lot of vintage stuff, and someone had a roll of 'aluminium' solder. Not sure what it was made from. Apparently unobtainium, because you couldn't buy it anymore. But it could solder copper to aluminium! I never used it though.

When you say some manufacturers, do you mean aircraft manufacturers? It's certainly best to keep the lead as short as possible. You need cable going to a starter motor. It needs to be flexible.

Fully agree. We always soldered our cables with gas. The flux was a paste from memory.

Particularly the 'motorbike sized' starters like Rotax and Jabiru. Just curious. Would be much easier to set up with automotive than tefzel. You can get pre-made lengths easily enough. Obviously a drawback is it would be more likely to create smoke in a dead short situation. My thought is that with an isolator, it shouldn't be a problem. The run is quite short in my plane too, which also reduces the risk of a short.

I think they use reduction gear starters now. Pretty sure my Victory did. At one stage Harley were using Hitachi starters 😄

Yeah that pic seems to be an aftermarket part from Turkey. Delco were ok. My own personal opinion was that Bosch were the gold standard in quality. Nippon Denso weren't bad (and as we are noticing on this little journey, quite ubiquitous on small engines). At the bottom of the heap in terms of design and or quality were Lucas, prestolite, magnetti Martelli and Hitachi There were niches of course. CAV made really good quality truck starters, albeit complicated. Bosch next in truck starters, then Delco. Delco weren't bad mind you. Just a bit simpler. Easy to overhaul though.

Damn it was hard to find a 3 brush starter example. I thought I was losing my mind 😄

Looks like the latter Rotax starters are 4 brush, and the earlier black starters are 2 brush

It's a very small force compared to everything else going on in there. A lot of the 2 brush jobbies are 90 degrees to each other. On my accusation of a RO-tax on the starter. Maybe I was too harsh. Here's the price for the similar Suzuki starter mentioned earlier 😲 https://www.cmsnl.com/suzuki-vx800-1990-l_model14275/partslist/FIG-23.html#.ZDZm6WR_U0E Price for that after market one is about $210 including freight as far as I can tell. 🤔

Oh actually, I think maybe two on one side and one on the other because one of the poles (I want to say +) might run hotter...

Most car and truck starters have 4 brushes. Some of the smaller Nippon Denso car starters had 3. Maybe I was mixing up that memory with something I'd seen recently! I never knew why 3 when I was an apprentice but I'm thinking it would be a way of increasing resistance for a lower current draw on existing 4 brush designs. Why not two then? Haven't the foggiest 😄

Apologies. I could have sworn I saw 3 somewhere!

You know, I've thought about it since more, and I'm tempted to buy that German after market F650 starter for shits and giggles. If it turns out to be not useful, it will be easy to sell on...

That's a two brush starter. What did you do for the third brush? Or were they ok? Can narrow down those kits to a f650 or vx800 starter. If you need to change the brushes for instance, there can be different compounds. That can make a huge difference. For instance, the only difference between a 12v 40mt truck starter and a 24v 40mt truck starter was the brushes, and you didn't undercut the commutator bars.

"Guten Tag The F1205 is sold out. warm regards" Oh well.

Yes that's the first link I found. That seems to be a car dealer. Doesn't matter, I'm sure there'll be something closer to home. The only problem now I guess is if the last model to use that starter was 2012 (not saying it is, but if it was) then NOS of starters is going to be thin on the ground. Motorbike starters wouldn't be a big seller to begin with. I know myself if it was my bike and it was out of warranty, I'd hit the wreckers first before going new. And then we are back to the aftermarket one. I'm sorry I opened that Chattanooga Choo Choo link now, it's screwing with my edit function... Let's see if I hear back from that German outfit.

Do you have a link?

Yes I still think of them as Nippon Denso. The Denso solenoid is made in Japan. Wherever the Denso starter is made that Rotax uses will be good enough for me 😁 So if it is an F650 starter, wherever Denso gets it made is obviously speccy enough. Although I think most of their motorbike starters are still made in Japan.

Good point, except that a badly made starter can get just as explodey as one that has the solenoid stuck on, which we decided in another thread might not be good for your engine. Although now I think about it, no shrapnel from this design of starter can get into the engine if it disintegrates. Maybe aftermarket would be ok to try, so long as you don't mind a dead short for a few seconds while the armature windings hit the magnets 🤔 Onetrack, Australia is not the UK so I doubt brexit would matter to a German supplier sending to us. a lot of the stuff vectriq are selling is made in Holland for instance. However I might try and contact an Australian BMW parts outfit about the F650 starter. See what they would charge.

They have quite clearly sourced the correct genuine Denso starter 🙂 I have shot them an email to ask about price and availability. Sometimes, like with my fuel pump guys, the info stays online years after the business has gone under. Let's see if they reply.

I have dealt with them before. Great service. They stock the aftermarket regulator/rectifier for the 912 that I bought 🙂 https://www.vectriqparts.com.au/product/rotax-voltage-regulator-carr5115/ I am becoming somewhat confident the starter is the same as the F650, so not too worried about the VX800 unless that is more easily had and at a great price since it sounds like you would have to swap housings. Doesn't look like vectriq does either. And while the aftermarket regulators are an improvement on the originals, I'm not so sure of the quality of aftermarket starters. That's a much harder thing to emulate well than electronics. If you are ok with aftermarket, then the guys I linked to earlier would be a source (provided I am right about the F650 being the same starter) https://www.stein-dinse.biz/product_info.php?language=en&products_id=524427#prettyPhoto

The German site is informative, but I'm thinking I've nailed it with the F650. When you have similar machines or within a range people making starter motors don't make different specs for every single machine out there. Classic example is the Bosch car starter, from about 1960 to 1990. The same starter was used on Holden's and Ford's, Ramblers and Triumphs. Only the front housing was different. The carcass was the same. I'm confident that Suzuki starter, f650 and Rotax 912 have the same carcass. And I strongly suspect the Rotax 912 IS the f650.

I should say, this is obviously for us Experimental, or 19 rego guys. I've had luck with the solenoid so far. Kyle seems to have found what fuel pump Rotax source. There's only so many things to measure on the starter, if I can get my hands on one. I might try and find a U/S one from the wreckers cheap to measure up. It's unlikely they are modifying the starters to suit their engine, but I concede it's a possibility. Most likely thing would be to machine the face plate for some reason. Still unlikely because they would have to pull apart the starter to machine it, and all that extra labour to potentially make it slightly weaker than it was before. Better to design the starter mount around an existing design. Same with the fuel pump- why reinvent the wheel? And I'm guessing it will be the same for the stator, and maybe rotor.

Phew! That was a lot of work, not even going TRY to look for the stator or rotor. You guys can do some research there 😄

Does anyone happen to know what other machines the starter and alternator appear on? I forgot to have a close look at the starter while I had the engine out, but I'm pretty confident it's a Denso. That makes sense since they also use a Denso solenoid (it does not necessarily follow, but as a manufacturer, if you've decided a companies starter motor is of high enough quality for you, then their solenoids should be too so why not stick to one supplier). Likewise, there seems to be a good chance the alternator is a Denso too. If not, following my logic, since the reg/rec is Ducati (which is probably Magnetti Marelli) then maybe so too is the alternator. That makes me sad, because if it's Magnetti Marelli, they kinda blow 😄 I have been having a bit of a look around while I compose this, and so far I have found these which are specifically for the 912: https://ecclestonaviation.co.uk/product/889751-electric-starter-set/?v=79cba1185463 (Rotax OEM 500 squids, plus freight) https://www.aircraftspruce.com/catalog/eppages/skytecRX12.php (improved aftermarket. 700-900 USD, plus freight. ) So going with my hunch, I started looking at pics of Denso motorcycle starters. Those superfluous lugs are a clue they normally bolt to a crankcase) I hit on the BMW F650 starter. It will need further investigation, my friend has a BMW F650. I can have a squizz, but not sure if I will have enough access. It certainly makes sense, since the F650 is also a Rotax engine. Single cylinder, so it would need ROUGHLY the same amount of force to spin as the 912. As well, someone else here pointed out that the F650 radiator cap is the same. What this is adding up to is that Rotax, naturally enough utilise what they are already getting for other engines they make. Of course the F650 has been around a while, so there may be a few iterations of the engine, which could include the starter. So even if it is the F650, we need to determine what years it used the same starter (if of course it is the same) The below link is for an AFTERMARKET F650 starter. Before anyone jumps the gun, I'm showing this link because it has quite a few pics from different angles. It is my preference to buy the same genuine part that Rotax buys, but paying the automotive price. I probably wouldn't get a cheap aftermarket starter. https://www.stein-dinse.biz/product_info.php?language=en&products_id=524427#prettyPhoto Too see exactly the same starter, it's useful to look for genuine second hand ones on ebay: https://www.ebay.com.au/sch/i.html?_from=R40&_nkw=bmw+f650+starter&_sacat=0&LH_PrefLoc=2&Brand=BMW&rt=nc&Brand%20Type=Genuine%20OEM&_dcat=177959 Particularly this listing https://www.ebay.com.au/itm/394431030976?hash=item5bd5ebe6c0:g:jbIAAOSwnQFjzr7C&amdata=enc%3AAQAHAAAA4BBbngib0YSE%2B6CMmjsCmTpUvXc9UZlt%2FfgQCtHur%2FN9tqAkwgwYcHrHWpcLICJlLUbPp3XbvdKtGA8KIW8R6raYzZcfQYI0gQP49M%2BQY7usc%2BqH%2BZgmY0sZwBeQTl%2BNZc0ab28Ev9pQvqeWGiUBDs7neO3lXe04bVr5ghxLIJleIFF8myKupAhmW1pZ09HT0OJTyX8IxFAibhoV%2BbPQavFTrJVmbVjI%2FPEtKbpSloRToz3CqwbwFicn6kkY7jWDj8A7psox9wg3rixECg3cM6Dl8EyZMoU3uWE%2BNtcoEv0E|tkp%3ABk9SR9K2rIXtYQ Of note, they clearly show the Denso part number ( 428000-5630 . Also 294 359 ) which is useful, should this turn out to be the correct starter. Again, gun jumpers, please I'm not intending to fit a second hand one unless I knew where it had been (only from a known 912 engine, not from a motorbike thats probably been submerged in rivers a number of times in its life 😄 ) If I'm reading the listing correctly, it's for models from 2006-2012. Italian listing, so not sure how well they translated it. They could mean only 2006 and only 2012, but that seems unlikely. Note that the Aircraft Spruce link also has some handy drawings with dimensions. Note that I'm attaching the pics from that ebay listing for posterity since ebay listings disappear after a while. The last pic (the clean, silvery one!) is of the genuine starter, for comparison from Ecclestones site. I am specifically only looking at the late model starter, as I believe the Black starter wasn't as powerful and should be upgraded anyway. NOTE NOTE NOTE NOTE!!!! I'm NOT saying this is definitely the same starter, but it's looking plausible. Something as simple as the wrong number of teeth on the armature could blow this out of the water (This starter has 9 teeth). Does anyone know anything else?