too much compression ??

[bob fell]

Hi All

just a question that might prevent me breaking my ankle....My Z1B is bored out to 1015 and apparently the head has been skimmed for greater compression, I was informed about this by the guy who did an engine rebuild for me about 14 years ago.....anyway I have always had to start it from cold with the kick start as the electric although ok when the engine is hot does not seem to have the oomph to fire it up from cold, do I need to upgrade anything i.e. higher voltage starter motor or battery?
I find as time marches on its a pain to put it on the centre stand get the kick start to it`s topest position and do gymnastics to get my full body weight crashing down on it several times (you would not believe the bruises from wearing unsuitable boots and kick backs)

any top tips ?

Bob

[hillbilly]

believe me,i know all about the bruises,iv got an xt500.hahaha

[steve.w]

u could but a spacer under barrell to lower the comp a bit bgb had to do this with his harris as it had the same probs .. it wouldnt turn over with a tractor batt

[Pigford]

You can get drag-race starter motors. If the starter is in good nick, and can start it from cold - it should work with a hot motor....

....if the starter don't work when its hot - probably just electical breakdown:

More Heat = More Resistance

[steve.w]

You can get drag-race starter motors. If the starter is in good nick, and can start it from cold - it should work with a hot motor....

....if the starter don't work when its hot - probably just electical breakdown:

More Heat = More Resistance

put ya glasses on and read it again

[hanskloss]

my stock starter happily turns 1075 higher comp pistons so yours should deal with stock comp 1015 no probs, I'd check/clean the ground connection to starter motor and the one around the kickstarter

[Rich]

Providing the battery is good:

Replace both starter feed and the main earth cable, 16mm2 welding cable is good.

If that doesn't work check starter brushes and commutator, get it skimmed and clean out the mica slots.

A CB900 starter motor will give more power than Z900/1000 units. You will have to alter the sprocket cover casing or it is possible to skim out the starter and relocate the brush holding plate if you have access to a lathe.

[steve.w]

my stock starter happily turns 1075 higher comp pistons so yours should deal with stock comp 1015 no probs, I'd check/clean the ground connection to starter motor and the one around the kickstarter

but if the heads been skimmed itll drastically increase comp??

[hanskloss]

but if the heads been skimmed itll drastically increase comp??

surely not as drastically as the higher pistons, if you could track how much's been taken off than surely some experts would chime in with precise advise, my head has been just licked to clear the old gasket imprint

[debben1]

1400cc with high compression motors start with no problem on the button so if 1015 wont then its probably poor battery, Yuasa batteries are good, poor wiring, or often its the starter motor now, many starter motors have had no attention whatsoever in 30 years, it could also be ignition timing issue down to weak spark, so check ignition, coils and leads, Dyna ignitions are good. Hope you nd you can sort it

[big green bus]

Mr D is spot on, I pulled a starter motor apart and it was full and I mean full of shit carbon, dirt you name it. I cleaned it up blew it out greased the bearings it is spot on now.

[steve.w]

Mr D is spot on, I pulled a starter motor apart and it was full and I mean full of shit carbon, dirt you name it. I cleaned it up blew it out greased the bearings it is spot on now.

wot about ure harris ??

[PAULJAC47]

Modern gel batteries are worth a cheap fix give around 20% more power!

[neilbarrett]

do what i have to do sometimes,a good push and bump

[zed1015]

If you still have probs after checking all the wiring etc get a later four brush starter from a J/gpz.
They are higher torque and should easily do the job.
Also if replacing the battery those Motobatt gell ones are very good and deliver more cranking amps than a normal lead acid one.