Still Smoking!

[ROZZER]

Standard Z1b, fitted new valve guides, valves, stem oil seals as they were all knackered and oil seeping around outside of exhaust valve guides due to someones previous molestations. Bores pistons and rings looked OK (0.5mm o/size) so refitted. New Dyna S with new advancer and coils fitted, carbs with new jets, standard sizes.
Guess what, after rebuild still mucho blue smoke from No1 cylinder and evidence from the rest, does calm down when warm but excessive from cold, plugs slightly wet looking and black - probably a dumb question here but would you agree a rebore etc is necessary? I know plenty of Zeds burn some oil but mine seems excessive, bearing in mind not run on road since rebuild (roads too salty) could it settle with miles or am I kidding myself?
Very depressed
I've never smoked in my life but I'm considering it to match the Zed!

[chrisNI]

Here are a few obvious questions just checking as I'm sure you did all these... Did you measure the rings when you had them out? Were the ring gaps in different places on each piston? Did you put in a new air filter?

Is it easy to start?


It might settle down a bit if you haven't given it a really good run - there could be condensation involved. You really need to get it out and do about a hundred miles and work out if it's really using oil and how much. What you do about it depends to a great degree on how much it's actually using. It would might also help if someone could follow you for a while and tell you when it's smoking.

The plugs shouldn't really be wet looking even if it's using oil.

Don't panic.

[Pigford]

JOHN, do a compression test on her! Best way to see if bores are shagged.

[davejames]

If plugs are wet it could be excessive fuel and not oil being burnt. Is smoke black or blue ?? Do compression test anyway.

[Rich]

Do the compression test and note results for all cylinders, this should be done when the engine is up to running temp with a wide open throttle. Then put two squirts of engine oil into the cylinder you are testing and repeat compression test. If the reading rises dramatically the rings / bore are the problem.

When in SEP picking me barrels up I was chatting about running in - no oil / wd40 / running in oil / engine oil and the subject went around to a goldwing that had been run-in at a steady 40 mph - smoked like wet leaf bonfire!! The bores were glazed after 400 miles of "running in", instead of taking it to pieces and glaze busting the bores as is the conventional way, they used a glaze busting oil. Run for 300 miles underload new oil and filter and no more smoke.

If you think the cylinders may be glazed it could be a lot cheaper / less hassle to try this oil. Give them a ring to find out which they used but

http://www.gb-lubricants-fuels.co.uk/PD ... 010W30.PDF

Will take you to a spec sheet for the type of thing.

[davy thomson]

John, after my motor was rebuilt it smoked like hell,but i gave it the big Fer run in a good blast to the north west 200 it has never smoked since so maybe it just needs a good run to settle the motor in better to suck it and see first.

[phil churchett]

John,
i echo what most others have said, wait until the better weather and give it a good run, at least 100 miles. Then take it from there.

[simon gilling]

John, my Z1 smokes like an H1 after it has been left on the side stand. Does the smoke seem as bad if the bike has been stored on the main stand? Old Zs don't like to be left leaning, although they always look cooler on the side stand.

I agree with all the other advice. If it starts ok then give it a decent run when the weather is better, then you can do a plug chop to check the mixture is not too rich and check the oil consumption.

Just go steadily through the checks, they are tough motors, don't strip it unless you are sure there is some thing to fix.

[Pigford]

Rich, good advice, I do like the 'to run-in or not run-in' debate! Good link too!

I don't think its just over-rich as I've had experience of this symptom. I got some RS38 carbs off eBay for my old Gixxer 1100, and when fitted she ran REALLY rich. The bike would start up without choke, run for no more than 1 minute then just soot/foul the plugs up & die!

After much chopping main jets, turned out the mains were 155 instead of 135 and the pilot jets were a 30 instead of a 17.5 and the emulsion tubes were too large! Must have been off a highly tuned motor! Even with this set up so over rich, to the extent she hardly ran, the bike was only puffing out a small amount of black smoke!

My old Z1A used to smoke for a good couple of minutes when left on sidestand (no main stand anyway!) but cleared after a mile or so!

[ROZZER]

Thanks everyone for the comments. Bike is always kept on the centrestand, this coupled with the fact that guides, valves and stem seals replaced really dismisses any chances of oil coming down valve gear.
Bike starts and runs great, needs choke to start but starts easily, I always cut choke ASAP after starting and kept revs up using throttle until warmed up - doing my bit for global warming!

Must admit I did not check ring dimns, my engine builder was convinced the problem was the valve gear 'cos it was in such poor condition, he said the bores etc showed some wear as you would expect on any motor but he thought they would be OK- kicking myself now for not doing rebore at the time - but cash was a problem.
Smoke is blue not black, however the fueling may not be perfect as I have set the float heights rather than fuel level cos I don't have the special tool - tried making one but not succesfully- anyone got one I could borrow? Float heights were all over the shop when I bought the bike and to obtain the dimension from the manual for the heights the tangs are bent a fair bit. Bikes history is non existant so anything could have been done in the past 32 years, mileage is unknown but crank, clutch basket and gearbox show virtually no signs of wear, quite conceivable that the top and bottom ends are from different bikes.
As I said initially smoke is pretty bad from No1, some condensation as is normal, but smoke very evident so there is an issue here. I will try a long run come the spring and see what happens. Can't afford to rebore anyway at present.
If I do rebore, what do you suggest- already on +0.5, Kawasaki+1.00 from Z Power is ?500 for piston kit, Wiseco 1015 10.25:1 kits I have seen at less than ?300, will I need to make any other changes for the 1015 kit i.e carbs? Any suggestions on decent workshops for boring to suit Wiseco pistons?
Thanks again for all the help to date

John

[ROZZER]

Forgot to say, before motor was stripped for head work, did compression check. All cylinders between 130 & 140 dry, with oil they increased 150 to 170. Because they were all within 10% of each other I thought they were Ok if not ideal when dry. (more convinced when head came off and saw the state of the guides/valves).
Gauges are all different, if I used another gauge the results would most likely be different due to calibration/accuracy so results can only be a guide to compression anyway.
With 20 /20 hindsight the results could have been interpreted to show a bore problem- Comments please.

[kiwiz]

If you need to rebore etc. I would go for a Wiseco. With their kit you get all the bits whereas my feeling of assembling all the OEM bits in oversize was a much more expensive excercise. Also most experts seems to think Wiseco produce better pistons.

My only concern was the increase in compression might require a jet change ( however it goes fine with Std jets), and a bit of a hassle assembling the engine due to loss of bore champfer on the rebored cylinders

[london calling]

SEP at Kegworth J24/M1 East Midlands,near Donington Park,for all engine and machining work.
TEL:01509 673295.

Try GREMLIN RACETECH for a great price on Wiseco Piston Kits,as well as braided hoses and all other bike related products.
Stephen Walls a.k.a. GREMLIN
Tel&Fax:01785 220899
Mobile:07950 876368
email:gremlinracing99@aol.com
www.gremlinracing.co.uk

[Rich]

I'd go with Jack for that - Gremlin did the best prices when I was looking a few months ago. The only way that would be cheaper is to import directly from the states. With the current exchange rates it is worth looking into even with paying duty.

Your compression figures are ok for std pistons, it may be that the bores are glazed and you just need to glaze bust them or the rings would just need replacing (but that is just as costly as buying a set of wiseco pistons)

[Pigford]

John, definitely go for Wiseco. A 1015 will only need a rebore, no other mods, oh, + Cometic head gasket too!
Me old Z1A had a wiseco with standard carbs & air box, and required no jetting. A fresh engine usually operates better & more efficiently, so doesn't always need rejetting, but a Dyno run is well worth ?25!