So here's my starter

[SteveD]

I've read recently that the recess where the starter is seated, top rear of the casing, can have a small deformity that might allow the starter to sit nqr in position. That might lead to the open starter nose to crack. Might be worth having a quick look before putting it in.

Can anyone else confirm this?

[Zombie Master]

I've read recently that the recess where the starter is seated, top rear of the casing, can have a small deformity that might allow the starter to sit nqr in position. That might lead to the open starter nose to crack. Might be worth having a quick look before putting it in.

Can anyone else confirm this?

I will. Is the deformity near the nose of the starter in the crankcase?

[Zombie Master]

1- Make sure the new starter has the same number of teeth as the old one.

2 - You don't need that front bracket anymore

Yes 9 teeth.

Should I reinstall the bolt from the bracket to block the hole?

[SteveD]

I've read recently that the recess where the starter is seated, top rear of the casing, can have a small deformity that might allow the starter to sit nqr in position. That might lead to the open starter nose to crack. Might be worth having a quick look before putting it in.

Can anyone else confirm this?

I will. Is the deformity near the nose of the starter in the crankcase?

I think it was, gear lever side. This is just a vague memory of reading something about it...can't confirm but if the casting seems a little rough and raised then maybe it is? Anyhow, it's a simple quick task to look.

[SteveD]

This might be the issue? Snowbum I believe...

The upgraded Valeo's, with the clips for the magnet structure, are OK....and, at least in the USA, are much cheaper, and seem to hold up just fine over lots of miles. There can be interference problems when fitting a Denso or Valeo starter to a bike that previously from the BMW factory had a Bosch. If you have one of the engine blocks with the problem, you can cause problems unless you fix it, and the fix is pretty simple. You do NOT want to break the nose cone of your new starter. There can be a Denso interference problem too, and the below article describes the interference problems for both Denso and Valeo, with photos of both situations. You'll have to scan the entire article.

See:
http://bmwmotorcycletech.info/boschvaleostarter.htm

[Zombie Master]

Yes thank you for making me aware. Since my bike did originally come with the Bosch I'm concerned.
So I'm a bit worried about using this new starter. Sounds like bikes that came with the Bosch starter may need to have some metal work in order to fit a Valeo. Looks like some filling can correct it, but getting it wrong could cause the nose of the starter to break. This could damage the flywheel. Again I fail to learn my OEM rule.

From Snowbum:
"The starter might not fit perfectly, may not want to go fully downwards at the nose area & the Valeo threaded bolt holes (or even Bosch unthreaded ones??) may not line-up perfectly. Inspect carefully, & use a half-moon fine file, or a small electric rotary tool of some sort, to make this inside area smooth at the top, with NO metal that is 'proud' (or of lesser diameter, causing a reduced diameter). You can feel this with a fingertip, and usually see it with your #1 eyeball. I have personally seen this and had to remove about .020" (+-), on both sides, at that top area. This is easy to do, & then the Valeo (Bosch?) should fit & mount correctly."

As I read about this subject, I'm hearing more warnings about aftermarket starters.

Maybe time to tear into the original starter and find out how returns are done on Amazon.

[jagarra]

Snobum's mod seems easy enough to fit the starter, the picture at the end of his article shows where to file,
you could do it in about 5-10 minutes.

[Rob Frankham]

Yes thank you for making me aware. Since my bike did originally come with the Bosch I'm concerned.
So I'm a bit worried about using this new starter. Sounds like bikes that came with the Bosch starter may need to have some metal work in order to fit a Valeo. Looks like some filling can correct it, but getting it wrong could cause the nose of the starter to break. This could damage the flywheel. Again I fail to learn my OEM rule.

From Snowbum:
"The starter might not fit perfectly, may not want to go fully downwards at the nose area & the Valeo threaded bolt holes (or even Bosch unthreaded ones??) may not line-up perfectly. Inspect carefully, & use a half-moon fine file, or a small electric rotary tool of some sort, to make this inside area smooth at the top, with NO metal that is 'proud' (or of lesser diameter, causing a reduced diameter). You can feel this with a fingertip, and usually see it with your #1 eyeball. I have personally seen this and had to remove about .020" (+-), on both sides, at that top area. This is easy to do, & then the Valeo (Bosch?) should fit & mount correctly."

As I read about this subject, I'm hearing more warnings about aftermarket starters.

Maybe time to tear into the original starter and find out how returns are done on Amazon.

I wouldn't take it too seriously. It should be easy enough to see if your block is one of the ones with issues and put it right. If the starter fits cleanly and evenly in the recess, it'll be fine. BMW supplies Valeo starters as service replacements for all years so there can't be any insurmountable problems. I've swapped between Valeo and Bosch on a couple of engines without issue. The Japanese starters supplied by some shops do seem to have a couple of issues but that doesn't apply here.

As for unbranded aftermarket units, I have to say I would always go with a branded unit for preference but there's no real reason to discount others as long as you realise you will probably get what you pay for. If you buy cheap, you get cheap. It'll probably work but quality control may not be as good so it may not last as long.

Rob

[Zombie Master]

So I've go the new type Valeo starter in place. Bolt holes seem to line up without any problem. I am concerned that unlike my original, there is no bracket on the rear of the starter. So the body of the starter, when bolted down, would be suspended without any support. I guess I could fabricate a bracket or wedge a bit of rubber under the body of the starter? How does the nose drive gear mesh with the flywheel?

Here is the starter in place but not bolted up:

[Rob Frankham]

Thew Valeo type starters, being considerably lighhter and slightly shorter than the bosch type, don't require the front support. There's no need to be concerned about it, there were many thousands of post '85 airheads fitted with Valeo starters and not one of them had a support. No issues.

How does the nose drive gear mesh with the flywheel

• The drive pinion is on a drum which slides on splines on the drive shaft. (Note. on a Valeo starter the drive shaft isn't the commutator shaft, there is a planetary gear set to increase torque and reduce speed between the two)
• The drum includes an overrun clutch so that the engine won't drive the starter motor if the starter is kept engaged too long.
• The clutch is moved away from the body by a forked lever that runs in a groove on the drum. The other end of the lever is attached to the solenoid slug.
• When the solenoid is actuated, the slug moves backwards (away from the flywheel) so that the lever moves the drum forward (towards the flywheel) bringing the gears into engagement.... a spring moves it back out of engagement when the solenoid is released.
• In contrast to an inertia starter, the gears are engaged before the motor starts to turn.
• The teeth on the drive pinion and those on the flywheel are chamfered to ease the engagement of the two gears.

Apart from the planetary gear, this system is common (in principal) to all starters fitted to airheads.

Rob