z650 sounds like a bag of bolts

[Bosun]

got the z650B running
all standard b1 apart frrom k&N air filters

runs and idles ok, but under 1500 revs sounds like a washiing mashine full of bolts and you can feel it through the bars

we know its meant to rattle a bit but this uis incredible, runs ok and over 1500 its fine

any ideas, big ends?????

we have a spare z750L4 engine ( i think thats the model) if not does anyone know if a fiddly swap due to electrics etc???

cheers me dears
so close to an MOT as well

[johnr]

under 1500 rpm? what, on the road riding it, or just ticking over under no load?
if its actually riding it, then you shouldnt really be expecting a z650 motor to pull fom 1500rpm in anything but first gear, i know theyre a nice motor but 1500 rpm is too low revving for the motor to be making any power at all. if its rattling when its not under any load, then id be pretty sure of the carbs being out of balance. imagine it as 4 single cylinder engines each with its own carb. if the carbs are out of balance, you have in effect, 4 seperate engines all connected, but all trying to run at different speeds. balance the carbs before you start messing with other motors. im 90%sure balancing them will solve the problem.
as or the z750 lump, it should drop straight into the 650 frame.

[Creature]

i would suspect either camchain outa tenstion or over worn or carbs outa ballance

[Dougie]

My GS runs like a bag o' hammers at tickover if the carbs ain't balanced.

[Bosun]

thanks for reply

sorry should have said on stand

will check carbs next

[Mustang Boy]

Fayji, what carbs have you got on it?
Should be slides.
My Z650 chop runs cheap k and n's and an open v. short pipe, think i've got 130 main jet's in it.
Balance the carbs and check ignition timing.
Think you should have points but mine won't time up any sense on a timing light so i've done it by ear!!!!!
Check points and condensors too.

Got loads of spares if you need anything gis a shout!

Cheers'en. :D

[Creature]

Got loads of spares if you need anything gis a shout! Have u got a spare float ????

[kiffer38]

z650s are another old ujm motor that had big end bearings that werent realy up to the job :o

[Mustang Boy]

Have u got a spare float ????
I don't think so old chap, will have a look today.
Suffering from post Farmyard ride home disorder.....(sore arse)!!!!

Cheers'en. :D

[Bosun]

Fayji, what carbs have you got on it?
Should be slides.
My Z650 chop runs cheap k and n's and an open v. short pipe, think i've got 130 main jet's in it.
Balance the carbs and check ignition timing.
Think you should have points but mine won't time up any sense on a timing light so i've done it by ear!!!!!
Check points and condensors too.

Got loads of spares if you need anything gis a shout!

Cheers'en. :D


cheers not sure on carbs, as really my brothers project, im a spanner passer :) and he produces things out of boxes

cheers all for tips though, balancing is next

[Mustang Boy]

z650s are another old ujm motor that had big end bearings that werent realy up to the job :o
That's the first i've heard of it.
I've had 'em for the past 14 years and don't ride 'em gently, but never had a prob.
Maybe i've just been lucky!

Cheers'en. :D

[critch]

z650s are another old ujm motor that had big end bearings that werent realy up to the job :o

what bollix....

i had em for years with no problems and i thrashed em unmercifully

me mate rode back from lemans with only two cylinders after welding his points together :rolleyes: didnt even mark the bores....

my last one had done nearly a 100 000 miles on it before we replaced the shells and finally gave it a rebore

not quite up to the job???



oh yeah recone your cabs are out fayji :D

[Bosun]

oh yeah recone your cabs are out fayji :D

thanks for that
we are trying that first as cheapest option :)

[johnr]

to be honest, the Z650 is one of the most bulletproof engines to come from japan, its right up there with the gs/gsx suzuki and the goldwing motors for longevity, and spawned the z750 and gpz750 which was developed into the gpz 750 turbo and the gt750, and the 750 was also the grandaddy of the zephyr 750. i dont think they would have developed it so far if it had been a pup. if you want poor jap bike engines, try early vf750, or early gsx400 suzukis, (dodgy cranks) early cx hondas, xs 750/850/1100 gearboxes, all pups, but z650's, it wasnt for nothing that the term bulletproof was applied to the z motors and still sticks.

[kiffer38]

i had a z650 hardtail it had the big ends go, got a replacement motor, same thing happened, so bollix it aint ! after 2 motors givin up that was the end o 650 zeds for me, stuck with suzuki motors with roller cranks, never had 1 o them chew the crank ! :mad:

[Creature]

im a honda man thru and thru and to make matters (some say worse) i ove the old 500/550 sohc models to bits. in fact 95% of all my bikes have been these models.

I recently brought kwack z650 - mainly on reckomendations of others and I know of at least 4 that have gone round the clock with nothing more than routine servicing.... and too be honest was amazed at the kwack....

but I cant wait to get back on a old honda sohc - remember them everyone says the chew camshafts !!!!!!!!!!!!!!!!! never happened to me - all i do is change the oil n filter at the correct times and use decent oil - problem solved....Theres always someone whos had this or that go wrong - maybe just bad luck or maybe the motor wasnt looked after properly by previous owners...

[johnr]

i had a z650 hardtail it had the big ends go, got a replacement motor, same thing happened, so bollix it aint ! after 2 motors givin up that was the end o 650 zeds for me, stuck with suzuki motors with roller cranks, never had 1 o them chew the crank ! :mad:

my mates had a half dozen of em over the years, all run to stratospheric milages on nothing more than oil, ilter and plug changes, and he's never had a single mechanical breakdown, of all the ones he's had, its always been the cycle parts and running gear thats worn out and broken before the motor. you sure you jut didnt buy a crap one to begin with?

[johnr]

i had a z650 hardtail it had the big ends go, got a replacement motor, same thing happened, so bollix it aint ! after 2 motors givin up that was the end o 650 zeds for me, stuck with suzuki motors with roller cranks, never had 1 o them chew the crank ! :mad:

and as it happens, my mate threw a rod twice in two months, one on a gs thou, and then on a gs 850. a year or so later i threw a rod on my 1100 katana, but that doesnt mean theyre all bad, my other kats are all bombproof.

[kiffer38]

looks like i got a couple o dogs at the time !, but it put me off em, just unlucky i guess :(