Broken Magna driveshaft

13 Posts | Latest reply on 12/08/2010 22:29:59 by retrofan | Go to original / last post
Warhed's Profile
Warhed

In: London, Ruislip
Posts: 129
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Title says it all. Bikes a mark 2 Honda V-4 Magna cruiser (VFR750 CH/CJ, solid back wheel, 4-4 upswept 'rocket launcher' exhausts) This model only ran from 1986-88 and very few were imported. Although old and scruffy it's quite low mileage, a great runner and a much loved steed so I'd really like to fix her up.

Unsurprisingly for such an old, low volume bike, most parts have been officially discontinued for some time. I've tried all the obvious sources - Honda UK and main parts dealers - no joy. Ditto Dave Silver and Part Search.

It's looking unlikely that I'll find new parts so I suspect that my best (only) hope is finding a breakers who has what I need, probably from a crash damaged machine.

Any and all suggestions gratefully accepted, TIA.
Scrapyard monster's Profile
Scrapyard monster

In: Forest of Dean
Posts: 52
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what's trashed on it  ujs or the shaft the're both sortable.   Someone made it once so it can be done  again any thing can be repaired or manufactured just a case of the depth of ur pocket compared to the length of ur arm,  ha ha let me know see what i can do         scrappy                                                                                                                                                                              
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WheelyNealy

In: Near Driffield
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would not a cx  or wingding drive fit it ? mind you scrappy may just have the answer for you there                                                                                                                                                                             
Warhed's Profile
Warhed

In: London, Ruislip
Posts: 129
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Thanks for replying guys.

UJ and actual shaft main body are 100% fine, it's the ratchet/sprung shock absorber bit at the back connecting the shaft to the rear crown gear that's utterly trashed - the interlocking lugs on both parts are totally stripped and they've terminally damaged the outer housing they sit in in the process.

Sadly CX/Pan Euro and Wing driveshafts are all mounted right hand side and so rotate anticlockwise, mines on the left, so it rotates in the opposite direction. The part(s) that I need essentially form a sprung ratchet which transmits continuous drive from the engine to the wheel under power, but slips, disconnecting the drive, if force is applied back the other way e.g. if you downchange too hard and dump the clutch it stops the back wheel locking up. It also acts in place of the cush drive rubbers on chain drives to take the lash out of the transmission, apparently (the complete unit is listed as 'shock absorber in the parts book)

Anyway, long story short, even if parts from one of those other bikes actually fitted the Magna shaft, I'd have no drive as it'd be turning the ratchet backwards.

From checking part numbers and manuals it seems that Shadow and VT/NTV V-twins's use a different arrangement and different parts even though they have left-mounted shafts like my Magna. Mark 1 Magna/Sabre parts would possibly work, but they're even rarer now. Subsequent mark 3 Magnas were chain final drive.

I still have some outstanding enquiries with a few US breakers, but it's looking increasingly likely that I'm going to have to go down the fabrication route - seems like these bikes are like rocking horse droppings as far as most breakers are concerned now, so I may well be getting back to you in the near future Monster.

Again, many thanks for your replies.
Scrapyard monster's Profile
Scrapyard monster

In: Forest of Dean
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Yep understand the prob from ur desription should be repairable
if no luck with ur search let me know
scrappy                                                                                                                                                                             
Wills's Profile
Wills

In: New Brighton
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I may be saying what's bleeding obvious, but have you tried the Honda OC and/or VJMC? You can join the Honda OC forum without joining the full club.                                                                                                                                                                             
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retrofan

In: pontefract
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Hi, I realize you're from london area, but when i was at squires at sherburn  the other day, there was a advert on the for sale board for a near complete honda magna for £150, don't know if this helps, just a thought.                                                                                                                                                                             
Warhed's Profile
Warhed

In: London, Ruislip
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Cheers Wills, HOC and VJMC were among my first ports of call and some of the guys I know in those groups are putting the word out for me, sadly no joy so far.

retrofan, thanks for that, something like what you've mentioned is exactly what I hope might bail me out and I'll be pursuing that ASAP! I am indeed in London, but sorting a van and a trip to Leeds (or pretty much anywhere in England) is more or less par for the course when chasing down parts for old/rare machines like mine, especially if it means getting hold of a complete scrapper that will possibly yield plenty of other useful bits.
Warhed's Profile
Warhed

In: London, Ruislip
Posts: 129
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retrofan - many thanks for that heads-up, I contacted Squires today and got the number of the guy selling the Magna and after chatting to him (he's in Barnsley) it's looking good.

He's actually selling the model before mine, but I've done a pretty exhaustive search online and through ex-colleagues in the trade (used to be a bike partsman in a previous life) and it seems that although there are some minor differences between the many versions of Magna propshaft, almost all the parts I actually need are identical for every model. Seems like the gentleman in Barnsleys machine should be able to provide all I need to fix my beastie. Time to sort a van...

As an added bonus, a friend has that model Magna so is likely to want to take whatever I have left over (most of the bike, probably) after I've looted the parts I need. I'll let you know how it goes.

Once again thanks for all your replies, it's greatly apreciated.
retrofan's Profile
retrofan

In: pontefract
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Hi Warhead,  glad it's turned out to be what you were looking for, i was going to get you the number the next time i was at squires which was this weekend, but glad you've already got it sorted. let me know how you've got on.   Nige                                                                                                                                                                             
WheelyNealy's Profile
WheelyNealy

In: Near Driffield
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wow result ! good lad                                                                                                                                                                             
Warhed's Profile
Warhed

In: London, Ruislip
Posts: 129
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Result indeed - me and a mate went up to Barnsley today and came back with a more or less complete mark 1 Magna courtesy of a very nice chap who chucked in a load of spare gaskets, crash bars and other unwanted Honda bits and bobs (he has a very tidy new Yamaha Road Star Warrior now)

He'd been tinkering with the Magna on and off for a few years before deciding that realistically he wasn't ever going to get round to making it roadworthy again. He even had the propshaft out so I could see for myself that it was not only exactly what I need, but also in very good condition. Appparent mileage is about 14k . Although the bike is cosmetically tatty from having been dropped a couple of times and then stood outside under a cover for a few years, that actually seems quite plausible looking at the general condition of the insides of the mudguards, radiator, carbs (removed and stored indoors) discs (almost no noticeable wear) sump bottom, engine paint etc. Main thing is that the propshafts on these are normally very solid. I've had them up to 70k with nothing more than a little slack in the UJ and they generally outlast almost everything else on these bikes (we think mine failed because a circlip keeping the springs tensioned broke)

More good news is that all the circlips and oil seals and most of the spacers and springs are generic and still available from David Silver at quite sensible (well, not outrageous) prices, so I'll be replacing those whilst I have it all in bits, silly not to.

My friend with the mark 1 Magna definitely wants to take everything I don't use - his is pretty much a rat bike now, high mileage and tatty as anything. I think there'll be plenty of useful stuff for him. I know for a fact that the discs, seat, handlebars, clocks, sidepanels and radiator/fan unit are in far better condition than anything on his bike - all stuff that would be bonkers expensive to replace new even if anyone stlil had them. All in all it's hard to imagine a better result really. Well chuffed.

Yet again, thanks to everyone, retrofan, Simon from barnsley and Mikey, the man with the van (who fell in love with Simons Warrior and now desperately wants one!)
retrofan's Profile
retrofan

In: pontefract
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Hi warhed,   Glad it's what you were looking for, brilliant.   Nige.                                                                                                                                                                             


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