Triple starter swap

[sfcpiet]

As long as it isn't notchy, it should be OK.

Needs to be a loose'ish sort of fit on the crank to aid fitment and also in the cover so that it "finds" its place when the sleeve nut is tightened. Don't be tempted to use any adhesive, good chance it'll self-destruct within minutes after starting.

piet

 

[Paul Marx]

As long as it isn't notchy, it should be OK.

Needs to be a loose'ish sort of fit on the crank to aid fitment and also in the cover so that it "finds" its place when the sleeve nut is tightened. Don't be tempted to use any adhesive, good chance it'll self-destruct within minutes after starting.

piet

Thanks for that Piet. It's probably a bit tight in the cover. It's damn cold in the garage at the moment. The cover has probably tightened up on the bearing.
I wasn't tempted to use any adhesive, be assured.

I shall now therefore proceed with re-fitting the ignition and alternator.

Paul

 

[Rokka]

152 € ? usually they cost more than twice of this.
As far as I know, the Bosch type has its sproket retracted and it goes out when the starter is activated. The new one is permanently in the gears of the starter freewheel, which may have an impact to the starter cluch- but so far with my one it does not.

The link shown in Paul's reply to 2622 on page 1 actually takes you to Bluemotor's starter for the 350s 500's and is only 400w.
this link https://newstore.bluetraction.eu/nl/4-dc-motor#/page-12 takes you to the 600w motor ( or I hope it does, I'm not the most techy literate person ever ) and the price is now 225€ before postage and tax, They seem to add tax on even though we are no longer EU so I'm not sure what happens about tax when it arrives as it's over a £100, if anyone has bought one as a result of this thread i'd be interested to know. thanks.

 

[Paul Marx]

The link shown in Paul's reply to 2622 on page 1 actually takes you to Bluemotor's starter for the 350s 500's and is only 400w.
this link https://newstore.bluetraction.eu/nl/4-dc-motor#/page-12 takes you to the 600w motor ( or I hope it does, I'm not the most techy literate person ever ) and the price is now 225€ before postage and tax, They seem to add tax on even though we are no longer EU so I'm not sure what happens about tax when it arrives as it's over a £100, if anyone has bought one as a result of this thread i'd be interested to know. thanks.

I bought one and blew up the idler wheel.
There's a helical gear on the motor shaft and the part holding the gear has a corresponding helical thread. The only thing stopping that part from advancing is a 1mm pin which shears when the starter motor is used. The third time in fact. Then, the gear is thrown forward, doesn't mesh with the idler any more and grinds the teeth down.
I contacted the seller explaining the problem. No response.
Apparently, the 400 W starter works fine, you simply need to fill in the gaps in the mounting plate above the screw heads.

 

[Rokka]

I bought one and blew up the idler wheel.
There's a helical gear on the motor shaft and the part holding the gear has a corresponding helical thread. The only thing stopping that part from advancing is a 1mm pin which shears when the starter motor is used. The third time in fact. Then, the gear is thrown forward, doesn't mesh with the idler any more and grinds the teeth down.
I contacted the seller explaining the problem. No response.
Apparently, the 400 W starter works fine, you simply need to fill in the gaps in the mounting plate above the screw heads.
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I read that with Interest Paul, I think either can be made to work ok IF you know about them in advance and have a lathe or mill with which to create some new parts and machine the existing ones, and thanks to your post and pictures we now do. As far as I can tell the only reason the outer sleeve is needed is to support the edge of the gear, as on the original starter the shaft is turned down forming a shoulder from which the threaded section continues. that whole helical containing sleeve thing should be removed and a shorter collar with two flats machined out of it ( to stop the gear turning ) welded on. this would replicate the orignal shaft and the bendix/helical section could be left exposed or turned off completely.
As many have said already the pin is completely U.F.P. and making it bigger would likely introduce a weak spot in the shaft. better to make a sleeve which would slide tightly over the shaft from just below the pin/end of the helix, to the seating point of the the gear which might actually strengthen the shaft rather than weakening it. what do you think?
one other question. Is the helical gear a permanent part of the shaft or is that also located with a pin or woodfuff key?

 

[Paul Marx]

You are absolutely right. I don't have the machining skills for that.
The problem with welding a collar with flats to engage the gear is that you will no longer be able to dismantle the motor completely sine the collar will not pass through the end cap come mounting flange of the motor. So you'd need to mill a new one or modify the existing one.
Paul

 

[Rokka]

You are absolutely right. I don't have the machining skills for that.
The problem with welding a collar with flats to engage the gear is that you will no longer be able to dismantle the motor completely sine the collar will not pass through the end cap come mounting flange of the motor. So you'd need to mill a new one or modify the existing one.
Paul

That's right. and that's why I asked if the helical gear is part of the shaft or an addition. the helical gear appears wider than the shaft in your photo, so it seems to me if the motor was assembled with the helical section on the shaft then as long as the O/D of any added sleeve isn't wider than that the motor should still come apart. Another question ( sorry to be a pain ) did the starter come with the gear or did you fit the one from your old starter if it did, is the fitmentnof the 2 identical and therefore are the basic bare shafts or the genuine and replacement motors the same diameter?

 

[Paul Marx]

That's right. and that's why I asked if the helical gear is part of the shaft or an addition. the helical gear appears wider than the shaft in your photo, so it seems to me if the motor was assembled with the helical section on the shaft then as long as the O/D of any added sleeve isn't wider than that the motor should still come apart. Another question ( sorry to be a pain ) did the starter come with the gear or did you fit the one from your old starter if it did, is the fitmentnof the 2 identical and therefore are the basic bare shafts or the genuine and replacement motors the same diameter?

I'd need to measure but the helical gear is proud of the shaft and integral with it, it's inner diameter is that of the shaft so it can be turned down.
You need to use a gear from the 120° starter motor, not supplied, with the corresponding idler gear.
Paul

 

[Rokka]

Thanks Paul that's what I was hoping. I can't see any need to turn it down other than for appearances sake to make it look more like the original but it will obviously pass through the end cap seal and bush if its part of the shaft so that means any sleeve added round the rest of the shaft can be at least that wide and not affect disassembly. I do have a good RGS gear and idler.

 

[Rokka]

Hi Again.
so I ordered the 400w starter from the website. however the same 600w motor with the sleeved helical starter shaft arrived. mine was slightly different than the one previously described in that it didn't even have a role pin or hole in the shaft just a lump on the shaft sleeve which slightly gripped the shaft, enough to allow a normal nut to be tightened but not enough to allow the tightening of a lock or nyloc nut on the end of the shaft without it turning inside the sleeve and climbing the shaft. As ever an auto response was received in response to my email but no actual sentient reply has been received.
So what to do. the original nut from my original starter is a flanged nut with a high grip insert. I was fairly sure that the hammer action of the sleeve every time the starter was operated would eventually loosen any standard nut so I was keen to use the high grip nut from the original shaft. The helical sleeve can only move at all if the nut loosens so it's massively important to make sure that can't happen. In the end I put a washer and then a slim locknut on the end of the shaft as that could be tightened up without the sleeve wanting to climb the shaft but I'b previously put screw lock on the shaft and the thread. After this was tight I could then put the original grip nut on top and because the lock nut was already on the shaft I was able to tighten the second nut up really tight. The two nuts ( for which there is just enough thread on the shaft ) should be able to hold the sleeve in place. I've used it about 10 times so far then taken the alternator cover off and checked it and there appears to be no loosening of the nuts whatsoever, never the less i'll be regularly checking this from now on, luckily it's a really easy thing to check.
the old girl is intermitently running on 1 and 2 at the moment so I won't be doing a lot of milage till that is sorted

 

[Paul Marx]

Hi Again.
so I ordered the 400w starter from the website. however the same 600w motor with the sleeved helical starter shaft arrived. mine was slightly different than the one previously described in that it didn't even have a role pin or hole in the shaft just a lump on the shaft sleeve which slightly gripped the shaft, enough to allow a normal nut to be tightened but not enough to allow the tightening of a lock or nyloc nut on the end of the shaft without it turning inside the sleeve and climbing the shaft. As ever an auto response was received in response to my email but no actual sentient reply has been received.
So what to do. the original nut from my original starter is a flanged nut with a high grip insert. I was fairly sure that the hammer action of the sleeve every time the starter was operated would eventually loosen any standard nut so I was keen to use the high grip nut from the original shaft. The helical sleeve can only move at all if the nut loosens so it's massively important to make sure that can't happen. In the end I put a washer and then a slim locknut on the end of the shaft as that could be tightened up without the sleeve wanting to climb the shaft but I'b previously put screw lock on the shaft and the thread. After this was tight I could then put the original grip nut on top and because the lock nut was already on the shaft I was able to tighten the second nut up really tight. The two nuts ( for which there is just enough thread on the shaft ) should be able to hold the sleeve in place. I've used it about 10 times so far then taken the alternator cover off and checked it and there appears to be no loosening of the nuts whatsoever, never the less i'll be regularly checking this from now on, luckily it's a really easy thing to check.
the old girl is intermitently running on 1 and 2 at the moment so I won't be doing a lot of milage till that is sorted

Fingers crossed. 600W is a lot of torque on those nuts.
Paul

 

[Rokka]

Fingers crossed. 600W is a lot of torque on those nuts.
Paul

It is. But depends on the compression, cc and no of cylinders of the engine. Its only forcing one 330cc ish cylinder over at once. Turning it with a spanner I was suprised how easy it was compared to my BSA B44 for instance. So cautiously hopefull but will be checking pretty much after every ride.