new bike and a half

Its a 1981 Honda CB900 with a DJP outfit on it.

It doesn't start, It needs a new Timing chain (supplied) and hopefully
that is all it needs on the engine front (thou I do accept it might
need major work or a change over)

other than that it needs a general clean up, a bit of surface rust
removed. maybe a new chain and some wheel bearings. Also its unreg.
I will also put in a rollcage and seat belt in the chair.

Its cost me $2500 and prolly another $1k to get it on the road...
cheap fun

http://martyh.com/cb900/54.jpg

http://martyh.com/cb900/55.jpg

http://martyh.com/cb900/56.jpg

http://martyh.com/cb900/57.jpg

 

No no Marty; the timing chain doesn't go on the front. It goes in the
middle!

 

I'll do it! My 2nd and 3rd timing chain installations were 100%
successful!

(Let's not talk about that first one).


BTH

 

Will you have it ready for the outfit rally in NSW in about 3 weeks Marty?

We could always take our outfits up to the rally


G-S

 

no.. thankyou, the last time I did look at a timing chain it was at
the front.. but it also had 2 more cylinders, one more wheel and a
couple of more seats..

the VFR had gears and I think the KLR was on the side

mh

 

can you please let me know how not to do it then?

mh

 

not a chance... maybe, but prolly not.

thats sound dirty...

mh

 

Isn't this the 900 they made out of the 750 and the jiggery pokery to
fit the head/cams in makes the timing chain the constantly busting weak
spot? Something about an extra sprocket in there somewhere.

Kim

 

I dunno, but I have been told that the top end on the 900 is a little
on the soft side...

but for $2.5k.....

mh

 

There is a sidecar rally in victoria in about 6 months... maybe you
should aim for that one.

Seriously, if you are going to take up riding an outfit you owe it to
yourself to check out the weird and wonderful homemade contraptions
people fit to them

Mine isn't the topless outfit!


G-S

 

You could probably pick up a CB750 DOHC motor cheap and fit it into the
outfit fairly cheap if it became an issue.

G-S

 

I think they used the 750 bottom end and relined barrels with new
broader head with wider apart cams. The cam chain didn't fit the chain
tunnel up through the barrels so they had to put in an idler sprocket.

My Suzuki GS1000 was a 1981 model, so I sometimes got in pub
conversations with others who had similar era bikes. Don't believe
anything you hear in a pub or on the internet....

Kim

 

I never heard that. I thought the 900 came out as a distinct new model and
maybe even preceded the twin-cam 750.
The only weaknesses I've heard were the famously misaligned frames and the
longish stroke (which caused higher than the norm-for-the-era piston-speeds
and conrod/gudgeon failures.)

 

1. Get a decent service manual first;
2. If for some reason you have to separate the sprockets from the
camshafts, use a torque wrench and loctite when you put them back on.
3. Try not to have visitors distracting you while you're working. ;-)


BTH

 

coming with the bike

almost bought a torque wrench yesterday..

thats OK... I have no friends

mh

 

Use new, genuine Honda sprocket bolts when you do. The old ones will
be stretched and can (and do) give up when you re-assemble with them.
For the cost of a half-dozen little bolts you could save a lot of
trouble later, seriously.
Oh, and line up the whole 'timing marks - chain links' thing a few
times till you're totally happy with it. One tooth out can make huge
differences and is dead easy to achieve; better to take a while to
make 100% sure than shag the engine the first time out.
Incidentally, if you have trouble getting spares (consumables and the
like) try David Silver Honda over here in UK - they do lots of stuff
for older Hondas.

Cheers,

Jeffles

 

As it turned out, I didn't *need* to remove the cam sprocket from the
CBR1000F motor at all, which made the snapped camchain and bent valves
all the more irritating.


BTH

 

Aye, now you mention it, with some bikes once you remove the pillar
bolts and take out the tensioner assembly you can sometimes just use
the slack to slide out the camshafts, although you'd still need to
'undo' the chain somehow. I *did* see a split link in a camchain once
(can't recall which bike) but think Therein Lies Disaster.

Jeffles

 

The GPZ900 one was already formed into a loop, and since the cam
sprockets are at the end of the motor rather than the centre it was a
doddle to fit.


BTH