105summat big bore and carbs

[RALPHARAMA]

I have just bought a Z1000 A1, imported from Italy. At first I was pretty convinced that the smoke emianting from the exhaust was oil smoke, it being fairly blue. On the way home it was smoking heavily, but seems to lessen closer to home. After a hundred or so miles I stopped at the services with the back-up team to check the oil level should she require an oily drink after wrecking the ozone for the last hundred miles, but the level was slightly over the upper limit already. I am aware that it is very easy to over fill a zed as I did this on one accidently many years ago which punished me by ejaculating a pint o black slippery stuff onto the back tyre, as I accelerated hard from reading a map in an effort not to get stuck behind an approaching lorry. You can imagine the laxitive effect of this event. I then learned why drag racers stick their breathers into a beer can! This bike has the breather going where Mr Quacker put it; into the air box. I am wondering if the previous owner over filled her with oil.

He did say that she smoked a bit when cold, which he attributed to the Wiseco big bore kit. When I bought her she had been ready warmed up and ran OK; well to someone who hasn't ridden a bike for eight years. The clutch is a tad snatchy but that'll either be a shagged cable or push rod. I started her tonight from cold after trying to breath hope into the brakes and found that she was very reluctant to warm up. Shaun (he's on here as Shaun) came around for general Zed chatter and when I tested her brakes and found they weren't much better, we swapped bikes (his A2 with single front disc) and found that mine is really guttless and that his brakes were massively better than mine. Have order braided hoses, master cylinder service kit and some pads. I'll prolly replace the piston seals in the calipers while I'm at it and add some of the wonder gunk a friend has been waxing lyrical about on the seals before installing them (sposed to be ultra slippy and makes the pistons move easier)

Sorry about the long preamble, but when I whipped a plug out it was covered in black sooty deposit, which suggested to me that she was running very rich. This supposition is further supported by the length of time to warm up and the fact the old old girl dosen't have the guts to pull a fifty year old divorcee with acne. I am guessing she has the standard carbs. She had a big bore kit fitted, by the owner previous to my vendor, who I don't think used her very much if at all. I was told that she had smoked like Winston Churchill in a streessful situation, and had the barrels whipped off exhibitting very scored pistons and bores, which is why she had the Wiseco pistons fitted (prolly cheaper than one size overs from Kawasaki).

My basic question is that presumably changing the swept capacity and shape of the combustion chamber will effect the carburation markedly, but what setting should be used? I'm hoping that someone will tell me that the standard carbs are OK, but I guess that they need different jets. the airbox is standard minus silencer and the exhaust is 4 into 2 with some after market Italian conical cans that are not disimilar in basic shape to Marshalls, but are quiet so prolly have standard back pressure.Ultimately I will either source a Harris 4 into 1 or make one outta 316SS, a major challenge for me - welding is OK but fabrication will be very tricky!

Can any one help with these dire carburation issues? Any advise on this would be much appreciated. Whilst I'm an aircraft trained engineer, I have close to zilch knowledge about tuning.

Ralph

[chrisNI]

What jets are in it? I would have thought with the airbox fitted standard jets would have made it a bit weak perhaps with the bore kit but wouldn't be that far off - I don't think the quiet four into two would change things that much. The standard 26s are a bit small really but it should still be possible to get it to work okay. A Harris probably would changer required jetting more than what you've got on.

You need to make sure the timing's right as well first off. Modern petrol makes the plugs burn quite black so it's harder to make sense of things than it was in the old days. Does sound rich though. Could be someone has stuck huge jets in it as a guess rather than using any science. If the jets are 120 or less there may be something else wrong.


Probably.

[steve bowdler]

I run 26 carbs on my z1000 with a 1105 kit standard air box k&n filter and home made 4 into 1,cant tell you what jets as Big cc set it all up sure seems to run fine,so you should be fine with a bit of testing.

[Pigford]

Even with the Wiseco & a 4:1, standard jetting won't be too far off
If its running rich, she shouldn't take long to warm up & run without choke
Clean out the airbox & filter, probably full of GTX
Try running with filter out to see wot happens, better or worserer

[RALPHARAMA]

Whipped all the plugs out tonight when the old girl started missing on no 2. The plug had died complet?. It was only making tiny sparks from the central electrode to the insulator; bloody strange, never seen it quite like that before. Odd thing is that there were a set of oiled up plugs in the tailpiece compartment, something you might expect on a stroker.The first two of these plugs wouldn't spart at all. I naturally swapped the plugs and leads around but it was clear that it was the plugs at fault. They were all NGKs. I wonder if they were from a duff batch sourced at a boot sale? I finally found one that worked and put it all back together. The old girl ran on all four again. While I had the plugs out I did a compression check and all the cylinders were around 75 PSI (+/-5PSI) whilst warm but prolly not at running temperature. Seems low to me but what is the consensus? I have no real idea what it should be for this engine.
The brakes seemed better tonight (though a long way from being good) and I took her for a nice run around Mendip. She was running much sweeter, but smoked like a true addict after her plug issue, but did clear later. Haven't taken the plugs out since I got back but will have a look tomorrow.
Thanks for all the replies so far.
Any views on electronic ignition for Zed Thous?

[uk kev]

Dyna-s

[chrisNI]

Compression is low at that reading I'm sure there'll be a few theories as to why I'll let someone else kick that one off...
NGK plugs and their propensity for dying after a soaking has been discussed a few times before on here a lot of us prefer Denso - NGKs don't seem to be what they were.

[RALPHARAMA]

I'm fairly sure that the old gurl needs another re-bore. I guess a 1075 Wiseco kit is prolly going to be the least financially painfull route to take. I'll not know for sure till I take the lid off, but my guess is that, assuming that there is nothing really ill about the engine, that whoever bored her out last time was especially good at reading and internal micrometer.
Any one know know of the most cost effective sourse of a 1075 piston kit? I will a punter (whoops - valued client) with an engineering company in Bristle, so I guess I should be able to use his knowledge to find someone to bore her properly. Does anyone know the limits and fits usually speced for a Wiseco kit (eg +.001" - 0.000 or H7etc), so I can make sure the job is done properly before I bolt it back up together. In my experience there are too many monkeys driving machines these days - OK, I'm a bitter, cynical old bastard!....but only through experience!

[davejames]

Ralph

Make sure you have the throttle fully open whilst doing the compression test.

[FLC]

sometimes a larger bore requires smaller jets, all things being equal cams valve sizes.etc because in effect you have fitted a larger pump thats pulling harder on the jets, does that make sense?
also i would have it dynoed before spending money on new bores/pistons as you will still have the same problem. having scrapped a set in my GPz 1100 i know how much this hurts but to do it twice ouch!
The problem sounds like overfueling which would wash bores and top up crankcase oil level. have carbs off for a look and to check jet sizes/choke linkages.
Hope this helps.

[RALPHARAMA]

I went down to see an old mate of mine today, who has a vacuum pump bleeding kit. I used his kit to bleed the brakes when I changed all the seals, pipes etc. They are now fab! He has a super duper Snap-On compression tester so I used that on the old gurl - try 150PSI on each pot.

She's still smoking and it looks pretty blue. Next job I spose will be to get the carbs right as she's prolly running rich as you say. A decent set of plugs would be good. I'll try and get some Densos on-line. I went into Fowlups on the way home, but they only had the dodgy NGKs. Incidently I assured that the Japanese NGKs are OK; it's the European ones that are iffy.

If getting the carbs right doesn't sort the probs then I guess it'll be time to lookat the valve guides.

[Pigford]

VDUK, sorry, but, if its blue smoke, that points to OIL mate, not RICH mix

[RALPHARAMA]

Yeah I know, but I keep hoping that I'm judging the colour wrong - tad unlikely, but there's nothing wrong with ungrounded wild optimism