Having identified the part at fault , the question now is where to source the part and does it need to be a factory part ?
With the support, technical manuals and assistance from the good people of this forum I was able to remove the clutch and gearbox from the MV . Thanks must be given to Donsy for the straight forward step by step instruction he posted
The offending part stopping gear selection was found to be a small spring ( Part # 800071009 ) that pushes a sliding pin against a floating key at the base of the selector fork drum
(see page g11 of parts manual ) also on forum.
Shown below are photos of the two keys inside the gearbox . The first pin is not holding the key in it's proper place. not allowing it to lock into position and rotate the drum as the gear lever is rotated.
My iphone is fearless!
Have not pulled this part yet but it sure looks small, can't cost more than $ 5.00 Right ?
Under a $ each, try Andre at Startwintrading Chris, you can get your new gaskets from them too. eMail him for cheaper shipping options if that's what you need.
Chris;
somebody else had the same problem, (or maybe it was you)
the bike would only shift one way, up or down (i don't remember which), i said it was item #25 p.G11
Thanks Noel, I originally joined in on another 312 gearbox thread,
Have to say some of the little things, comments posted may seem trivial to an onlooker but are important when it comes to passing on the the knowledge and therefore confidence.You guys are the kings , Thank you to all the Senior Members.
Donsy;
is far as i know the only 'different' transmission is in the SPR
its +10 % on the bottom and -10 % on the top
i wish i had the money for one of JDS's transmission kits......but i don't:bawling:
my Brutale is too short on top, i'd like to change 5th and 6th
Chris;
i didn't use search, but i'm very familiar with transmissions
MV has the best stock transmission i've ridden.....and it does have the best shift mechanism......
as long as you don't put the little shift lever bushing in backwards, because it WILL fall out:jsm::jsm:
The EVO3, SPR and Senna 750, had different gearboxes Noel.
I think I might start looking at the Brutale ratios just for fun, but pretty sure they are the same as the F4's.
I found one bent fork, and two badly worn forks between the 2 gearboxes, so not bad at all for two highly abused gearboxes.
I will have a look next month to see what Andre wants for new forks, might as well get new one's, the gears in those boxes of mine are like new, testimony to what you said about it being good equipment.
Donsy, I think your'e getting Evo3 confused with the SR final edition. It has the SPR/Senna gearbox. Evo3 is same as 1&2.
From the engine designer Andrea Goggi :"F4 EV03 engine is same as EV02, only with painted pick-up, clutch and sproket covers (same color as Brutale)."
I've got a complete Evo1 motor I probably need to part out....:naughty:
AGO also Noel ? I didn't know that.
I do believe the EVO3 is different to the SPR, sort of in between the SPR and regular gearboxes.
I will look up the ratios, if I can find them all again somewhere Noel, thanks for that.
.
Sorry Dons.. I haven't got any gearbox forks in stock ( only a couple of new gears for the 750's)..
As you know, CAG or Mark is your best and cheapest bet for these second -hand parts, as long as they're prepared to split a gearbox unit .. I can get them new from MV with some trade discount, but I wouldn't know what the time scales on delivery would be..
Just to play devils advocate , why could metal not be added to the forks and the bend corrected with some heat ?? Be gentle with answers guys , John Britton welded his cylinder liner before a race plenty said it shouldn't work
Noel,
You are scaring me which part are you referring to, I don't wish to put any part in backwards !
(remember you are viewing my pics from the northern hemisphere they may look upside down but not backwards)
Thanks Noel, I will have a look at all these things.
It can't be the Q/S though, as you still manualy use your foot to shift, maybe my foot riding the lever a bit.
the ratio spread in the 2 boxes
2.456 to 1.981 or ~20% tighter
so 1st gear will be 10% faster and 6th 10% slower.....
i tried going through my parts books but there are too many updated numbers to compare.....but a few of the numbers are the same on both the main shaft and the counter shaft
my bet is the F4 and Brutale have the same internal ratios
Ian; i don't think Brutales have a shorter 6th....it just seems so right:drummer:
Thanks for welding and straightening reply Noel. Not knowing cost of replacement or delay just thought the question needed asking as a kiwi I am logging that as. It is possible !
On arrival of parts I will be vigilant in my reassembly
the 750 Brutales are geared
1. 2.92
2. 2.21
3. 1.78
4. 1.50
5. 1.32
6. 1.21
same as an F4 except for 2nd (2.12) and 6th (1.19)
primary is 1.72 (47x81)
910 Brutales are geared
1. 2.92
2. 2.12 same as 2nd in a 1000 F4
3. 1.78
4. 1.50
5. 1.32
6. 1.21 lower than a F4
but primary is 1.58 (50x79) like in 1000 F4s
There is a good side to having such a mechanical failure it is the great opportunity to inspect and do those things you always mean to get around to, Have serviced rear hub, found petrol overflow pipe not connected from last service ,found missing screw from underseat wire retainer in engine crevice ,found crack in exhaust weld at four into one,will probably give exhaust a polish while it's off "be rude Not to" generally clean and check over everything as you do. Tracking says parts have crossed globe and are now in NZ now watch them take twice as long to get across town!
Ordered from Star Twin , Our forum linked suppliers Rock.
Thanks for tip Dons, actually looking forward to doing the install ,
Am I right in thinking these would have been access able without removing gearbox throught side plate on box ??
If you are suffering from a gearbox problem thought to be caused by a faulty gear selector return spring or the springs on the selector drum rotator you Do Not have to remove the gearbox to verify or replace these parts .
To access these parts drain oil and water, remove water pump from motor and allow to hang or tie back should you find it in the way , remove he gear selector from shaft and the three hex head bolts holding the select cover in place, from here you can inspect or replace the springs on the selector side of the gearbox . Although for me I was happy to remove and inspect clutch and gearbox and to gain the expierence But the simple replacement of the selector springs could be done in a comfortable hour or so
Have just finished installing selector rotator springs, refitting gearbox and repacking clutch plates , at time of removal the clutch and sprocket nut both were found to be only just seated only held in place by the lock washer on inspection the clutch nut is partially stripped from being cross threaded by factory and needs replacing.So for me the removal and inspection has surely been worth while.
Well done Chris. If you told us what was wrong we would have told you where to look first ...lol.
Anyway, good thing you took it apart, did you get a new nut, cos I have a few lying around in new shape as I don't use them at all.
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