Pigfords OLD effort......now JULES NEW PROJECT!!!!!

[Pigford]

Al, static timing is OK......

Have checked the timing marks with a degree wheel so used that ...... Lawson has Dyna S (Black Zed has Dyna 2000).... You can hold rotor on full advance by hand & adjust backplate so it sparks at the mark
Its near enuff for what I'm doing.

http://www.z1ownersclub.co.uk/forum/vie ... 0566#70566

As for comp ratio..... Not checked.... Coz its a 10.25:1 Wiseco... and I have Unitrack barrels, the comp ratio is probably a bit less..... but to be honest, no idea what The Uni barrels are about 1mm taller

This could be a point..... coz if its too low it'll be a pig to set up to idle I shall see if I can borrow a compression tester as a starter Cheers

[Rich]

Do you have air adjuster screws on the pilot system, use them to see where you want to go with the jets. When you say it won't rev over 1/4 that should be off the pilots and on the main system.

I think you'd better do a comp check if you are using that barrel / piston combination as I heard it was good for turbos!!!!

[london calling]

Back to the drawing board Piggy,sorry I mean't IRONING BOARD

[Pigford]

Rich.... they're "fuel" rather than 'air' screws...... RFS have the screw at the 'barrel' end of the carb, not filter end.

I suppose I could always get the head skimmed if needs be

Will do a 'gauge' comp test this week

[steve.w]

try a different set of carbs ive had this problem before with a mk2

[Pigford]

Up-date.

Thanx to help from some very very nice members..... I have made a few more steps forward.

I have measured the compression ratio and it is a healthy 10.44 : 1 (Cheers Romeo)

Checked the compression pressure using s gauge that screws into the sparkplug hole. I was naughty & did it with a cold engine (supposed to be operation temp) and got a range of 105 - 115 psi

I then did the oil thing for the ccv (combustion chamber volume) to get the comp ratio, and after cleaning out most of the oil, redid the pressure check and got 200 psi

So I think thats soopa doopa. The engine being fresh & cold won't be sealing to well yet, so this test will need to be re-done when its hot

Next on me list is to dial in the cams.... I have faxed Megacycle Cams Inc & await a reply to confirm cam type & settings

[Rich]

No good for turbos then!

[Ginger Bear]

Up-date.

redid the pressure check and got 200 psi

'Kin Hell

[kano]

can too much compression cause starting problems?
my uncle used to tell me that when he re bored his barrels, he would leave them out over night to pick up a bit of surface rust to allow tiny imperfections.
for this reason but this was a triumph and a long time ago.

[Al]

Cautionary note on rebores for any who did like me.

Had my J barrels honed after they had run new pistons and rebores for two years with the previous ownerbut had then stood for seven years which is when i got hold of it. If that makes sense.

New rings went in with this hone and i ran it in carefully for 500 and then bonkers after that.

Smoked like mad when it had been honed and over the last three years has got progressively worse and worse and worse.

Had the top end off it now for new barrells and new pistons etc.

Looking at the old bores that i had honed;

Firstly they are golden yellow. (glazed)
Second thing you notice is that there are still honing marks very deep and very visible all over the place.
Next; many of these honing marks have carbon built up in them.
Lastly; there are discrete but highly noticeable patches randomly scattered about all four pots where the rings have never touched!!!!!!!!! Four or five patches per pot on average.
It looks like the honing was done with an angle grinder!!!
No wonder it smoked like Dot Cotton.

I think moral of this tale is dont run them in too lightly!


AL

Not an attempted hi-jack but rather a comment on what your about to do Mark!

[Pigford]

Al, apparently there is an ART to honing...

You can easily end up with non-circular bores......
Some honing tools that are used are too short and you can end up with different diameter bores top & bottom

Best to get it done by a 'true professional" who is used to doing Jap bikes & ideally comes recommended....

Its a Circus Out There

[Pigford]

OK............. not been tinkering much over the last few weeks....

Chased MEGACYCLE about the cams...... they reckon the are CAM MOTION I emailed Cam Motion who say they need more info.
Apparently there are ID marks behind the cam sprox Before I take the cams out again, I decided to try the RFS36's off the black Z1000, which I know are OK
Lawson started OK (bit smokey burning off the oil I tipped into #4 when I did the compression ratio check) but it still 'hangs up' on the revs

Ignition timing is OK (Dyna S set statically with 'F' on the mark & rotor held fully advanced)....
Nice correct grade Denso's....
NO air leaks in carb rubbers....
Carbs have twin cables & are closing properly....
Engine sounds reasonably OK....
Decent fuel now in tank....

So, what's causing it Could the cam timing make this happen (Don't see how really).

Can't see how its running too rich... carbs are OK on the 1075.... so shouldn't be too rich on the 1170

The bike starts & runs OK, so must be set up about right.... the cam sprox have not been touched.

Any bright (useful) ideas anyone

[tlc]

And why shouldn`t it be too rich with larger capacity ?

Increased displacement doesn`t necessarily mean increased fuel flow !

[Steve Cooke]

Mark as long as there's definitely no air leaks, the revs hanging up at idle is usually a sign of too lean a mix in the pilot system as opposed to being too rich.

[Ginger Bear]

Mark,

I have some standard cams kicking around, you're welcome to try them, if you want to. Even if it only eliminates the cams you have as being the problem.