DR.......BIG Bang

[Dave#22]

Hi all, I had hoped to visit Llanthony on Saturday, but was stuck down by a bug on Thursday which knocked me for six until Saturday, so I went for a ride into North Wales on Sunday and on the A470 just outside Betws y Coed, DR BIG lurched and went clatter clatter etc until I pulled up, I had thought the chain had snapped until I looked down and saw the starter gear housing lying at a peculiar angle and the clutch cover split from top to bottom and a large pool of oil appearing underneath. On further investigation there was a fist size hole in the front of the crankcase with no conrod visible( memories of the first TC ride when Bruce's Goldie went bang), the rear balance shaft had burst through the case smashing the starter motor.......anyway a call to the RAC was made and it took 6 phone calls and 4hrs before I left the scene.....not good!
ps. anyone know a good ally welder.....only joking, there are very few usable parts left, it looks like a grenade has gone off inside the engine.
     Dave   

[guest7]

Sorry to hear that Dave... which one was it, the nice shiny touring one?

Anyway, hope it gets better soon.

Any thoughts on why it happened?
GC

[Dave#22]

That shiny black one is not quite as shiny now with 70,000km on the clock and out in all weathers, it was my old '88 DR BIG which I rebuilt a few years ago with '95 DR800 running gear (I came to Llanthony on it two years ago). It looks like the conrod has sheared below the piston (probably metal fatigue) and taken most of the internal parts with it.......but it did rev well when it was running.....
Shame I didn't make Llanthony, I wanted to see the Gospel Pass in daylight, unlike last Easter, when Pat & I came from Hay in the dark in gale force winds and torrential rain I thought we were riding down a river bed. I was so glad to see the Half Moon Inn that night.
      Dave

[Jez F]

Hi Dave, I've just bought another DR750 lump, that makes 3! Do you need a bottom half of a motor? If so, let me know and we can agree on a price.
Jez

[Steve H]

It looks like the conrod has sheared below the piston (probably metal fatigue) and taken most of the internal parts with it.

Thats going to have made a mess !.
Does it look like this ?

[squirrelciv]

Ouch!! Bad luck buddy Look on the bright side, at least you'll have something to fiddle with in the shed this winter, or is that pushing optimism too far

[Dave#22]

Hi Dave, I've just bought another DR750 lump, that makes 3! Do you need a bottom half of a motor? If so, let me know and we can agree on a price.
Jez
Thanks for the offer, but I havn't dug out my spare parts yet to see what I have available.....I need to get my project bike to a position where I can ignore it for a while. Can you give me you phone number and if I need a bottom half, then I will give you a bell.
    Dave

[andy230]

Hiya Dave-

Just saw this on the british supermono site.  I presume its in europe, which is a massive hassle, but I just thought it may be of interest?

cheers....

a

---------------------

I have an engine of Suzuki Dr Big 800. I bought on
January 17 2008 on ebay to build a
supermono, but I lost the sponsors so it's remained in garage until now.
Missing the carburetor and alternator.
SUZUKI MOTOR BIG 800 SR 41
The sale of 800 € treatable + shipping

[Jez F]

Hi Dave, I'm in sunny Wolverhampton, phone is 0one90two, 7five2nine5one, leave a message if I'm not in and I'll get back to you.
Jez

[Dave#22]

Hi all, thanks for all the info, after digging through boxes of parts I have most of what I need to build another engine for DR BIG and still complete my project bike.
     Thanks again
       Dave

[guest7]

I am sooooo looking forward to seeing the project bike.

(for those who don't know, Dave's workmanship is superb and the detailing of his projects is a joy to see).

GC

[Dave#22]

Hi all, I took the dead engine out of the DR today, removed the head and barrel and was amazed that there was no conrod on the wrist pin. I found it's remains in the sump....but when I examined it, the first fracture was obvious, but the rod then split vertically up to the wrist pin, then disintegrated, removing most of the contents of the crankcase.....(photos submitted)..amazing.
    Dave
ps. all I can salvage from the mechanical mess is the alternator, the clutch and the head assembly, which suffered a bent inlet valve.

[Steve H]

[squirrelciv]

Dave mate, I think you're just being overly pessamistic. Bit of araldite and a smear of old chain grease and you'd have her back on the road in no time

[Andy M]

People work for months making cross sectioned motors. This one seems to made it all on it's own 

Good Luck and hope you are back on the road soon.

Andy