danny_galaga

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?

oh, i can see in the manual it is Setrab, same as the oil coolers. Setrab have agents in australia. I'll see if i can find a part number in the picture, otherwise i will still have to have a physical look.

I've been having fun taking note of alternative spare parts for my build. I will try and see what brand my radiator is next im at the hangar. Bushcat roughly similar specs to the Savannah.

I got a tablet JUST for flying. So I've only installed a nav app, and the build manual for my aircraft. I actually deleted some of the preinstalled apps as soon as I bought it just to keep it 'light'. I just filled in my application. fairly straight forward, but I always worry I forgot to cross an I or dot a T 😄

A bit of a crossover of my two hobbies. Long read, but very interesting 🙂 https://www.kotaku.com.au/2023/03/the-racing-game-that-changed-everything-was-built-on-lockheed-martin-technology/

https://bydanjohnson.com/fantasy-or-fantastic-futuristic-retro-junkers-introduces-distinctive-a50-junior/

Received my solenoid from the kart shop ok. I was going to buy one from Ecclestone aviation in the UK where I bought my Rotax fuel pump from but I forgot. Hence my mad scramble to find something in Australia 😄

I'm way over the hump now with my project and I definitely wouldn't have kept it as long as this guy, but a few of us have been there https://www.kitplanes.com/stalled/

Looks like you've avoided the RO-tax 😄

Agreed. I've seen it, having been an auto electrician, but it's not common. But what I'm driving at I guess is you increase the risk of it happening if you get a cheap solenoid. The contacts might not be as good a grade of alloy, or not very well aligned etc. So the original thrust of this thread was to find a reputable solenoid brand I could go with that is available in Australia. The mercruiser one was mentioned, but hard to know if I'm getting the real deal or not. But everyone can stop looking, because I've discovered a popular Rotax engine that uses the same Denso solenoid 🙂 https://www.rotax.com.au/shop/item/starter-relay-evo Which you can get from Go kart shops etc. My journey is done, and I'm also fitting a starter indicator light as well thanks to this thread. Thanks guys!

I think I've covered all that in previous posts. If engine continues running with solenoid fused, starter destroys itself through centrifugal force because the starter will remain engaged with the engine. Ratio of pinion to ring gear is easily 20:1 so even if the engine is only running at 1000rpm, the starter is spinning at 20,000rpm! If you stop the engine, then starter keeps spinning the engine over until battery goes flat, or starter melts down. As you alluded to before, starters don't like cranking for long..they get hot really quickly. If it has field windings, the insulation burns up causing shorts . And whatever type, the armature windings can also short out if very hot. The brush tags, if soldered can melt off. If the armature has soldered commutator segments, those can also melt. Molten solder is a saving grace in this case because everything becomes open circuit very quickly. The only way the starter would keep spinning for any length of time is if the pinion clutch failed, or didn't engage the ring gear. Then the starter would spin quite happily for ages. Although that would give you plenty of time to disconnect the battery 🙂