My Guzzi 950 has eaten it's starter!

The nose casting which holds the shaft that the bendix slides on has broken off on my Bosch starter

My friend who is a proper engineer and fellow Guzzi enthusiast thinks that the starter ring has got worn / damaged and when the bendix has “ridden” the ring it has put strain on the casting and subsequently broken it.

My Guzzi has always been a poor cold starter (but OK when hot), turning the engine once, nearly stopping and then turning it again, etc, so either the starter is weak or I have too much static advance??

So I am fitting a new starter ring and was wondering about taking the Valeo route as I cannot now exchange the Bosch starter. I know about the magnets falling out of the Valeos but understand that that issue is now apparently sorted?? I have heard that the Bosch are ultra reliable but struggle to turn the engines over…which on mine has proved correct. It is a 950 with 9.1:1 compression.

Experience/opinions please.ReggieV2014-03-15 20:12:26

sent you PM
I would have a bosch over the valeo as they seem more robust and more powerfull to me
if you let me have all the bits I can dares say find a front casing in my spares and build you one as good as new

The later Valeo starters are much better. There is also now a Bosch permanent magnet starter available, as fitted to the CARC bikes.There are also other starters which will fit and which have been mentioned here.The valeo design does produce more power than the older Bosch, as it is not a direct drive starter.

Blimey never heard of that before

My Guzzi has always been a poor cold starter (but OK when hot), turning the engine once, nearly stopping and then turning it again, etc, so either the starter is weak or I have too much static advance??

Sounds more like a battery problem. (?) The starters usually turn over Spadas etc. OK, even 950 Le Mans conversions.

Mike H wrote;
Sounds more like a battery problem. (?)

I’ve got a 3 month old 32 ah Motobatt battery and some state of the art Gutsibits battery leads so I’m confident that’s ok.

What I haven’t also mentioned is the Guzzi has also eaten my spare “tired” bosch starter in the same way.

And to top it off car went off the road on Tuesday (a/c compressor broken and sounding like it will sieze up), T160 already in bits and Norton started playing up and wont run properly which I think is the electronic ignition self destructing.

I’ve never had so many problems arise with vehicles in one week, and I am mega **ssed off.

Looks like I’ll be walking to work in the morning Grrrrr.

p.s. If anybody has a totally knacked starter motor, it migh help me out if you want to release it.ReggieV2014-03-16 13:17:58

how many teeth you have on the starter gear

OK on second thoughts as you were, something wrong with ring gear, if there something jammed between two teeth for example that might do the breakage.

Edit: also if teeth are binding for some reason, would also explain starter being very slow or hardly turning, too much load.

Is starter not flat on bell housing or bell housing distorted?
Mike H2014-03-16 16:10:08

reason I ask is you can get themwith different teeth numbers on the starter this results in the gear being a different diameter , if not enough teeth to small diameter and therefore it does not fully mesh with starter ring resulting in the teeth chewing up and jamming

Ray, both starters have 8 teeth.

Mike H wrote;Is starter not flat on bell housing or bell housing distorted?

Starter fits the bell housing perfectly, and as far as I am aware the housing is not distorted.ReggieV2014-03-16 22:09:39

will check for you



I had the same on my Spada III, no matter what battery I fitted. I also put in an extra earth lead from battery to crankcase to no avail.This bike should have had a valeo starter according to the spec, but an older Bosch was fitted. It would often stall before turning the engine over TDC. Second push of the button always worked.

Can get the alli nose casting still as a new Item aprox £40.00 so the lot is repairable

BUT need to find out why they’re breaking (sorry if stating the obvious)

Mike H wrote;BUT need to find out why they’re breaking (sorry if stating the obvious)

I think the reason it is happening now is because the starter ring is ****ed up. Why / how it got like this I don’t know. ReggieV2014-03-17 20:33:37

Well if you fit the new flywheel ring and a new starter motor, you should have no more problems.

some rings get buggered because the starter starts spinning to early and chews the end off the starter flywheel ring and little starter gear
I am doing one at the moment that requires a new gear on the starter as 25% of it is chewed up I can only imagine the flywheel ring is the same

Or, operating starter while flywheel is turning wouldn’t do it much good either, e.g. rain water in starter button (have had this happen), or, just playing silly b*ggers with the starter button while engine spinning or trying to restart before it has properly stopped turning from last time (cars typically have a lock out so you can’t operate starter again without turning it off first)

  • for the Bosch starter I ahd tried a Valeo on the older Guzzi it will not turn it over on a cold morning long enough to get it started. The Bosch I find is reliable and will take all sorts of abuse.They are also easily rebuildable with a good network of auto repair dealers.

Brian UK wrote; Well if you fit the new flywheel ring and a new starter motor, you should have no more problems

That is what I will be doing.

I rang Nigel at NBS about this last week and he suggested the starter motor relay could be sticking/ not releasing the solenoid and causing the bendix to get stuck in the ring gear with the engine running, but when I tested it without the starter, it worked OK, but I am also fitting a new starter relay …just in case.

p.s. I’m fast becoming an expert at crabbing the frame on this bike as my gearbox ate its speedo worm last year and I had to get that repaired, so it was a “gearbox out” job. ReggieV2014-03-18 21:17:11