what PHONY 'HOTTER CAMS' look like!

1978 kz1000 A2, standard edition.

Well the prior owner told me "Sonny, this here '78 kz1000 has a 1137cc kit and hotter cams."

NO, I DON'T THINK SO.
I pulled the valve cover gasket tonight to check the valve clearance and to my (untrained) eye, the cams look like STOCK KZ1000 cams. I found no special markings on them. If they were aftermarket cams, wouldn't they have a manufacturer's name somewhere? Didn't find one!

The valve clearance is fine -- I couldn't even fit a .1mm feeler gauge at all between the cam lobe and the shim after lining up the marks etc. as per the FSM.

I suspect some 'ace mechanic' ripped the old guy (prior owner) off. The prior owner was in his 60s when he 'had the hotter cams and the 1137cc big bore done' -- yeah they really 'done' him over but good.













Here's the coils on it:




Here's the carbs on it:






NO WONDER this bike doesn't pull my arms out of the socket. It most likely is on stock pistons too. They fed the old man a line of b.s. and took his money.

Cams, carbs & coils look like stock components.

Pull a plug on #1 or #4, bring piston to TDC and see if there's any dome on those pistons.

Sounds to me like your initial jetting estimate was pretty well in the ballpark but I think I'd drop the mains to 112.5 or 110 with stock airbox and go from there.

Put needlse in 3rd groove.

Pilots should be the long nose pilots and #15 if they're stock.

Pilot fuel screws are a hit & miss deal on those old carbs. Start with 3/4 - 1 turn out from lightly seated [closed] and work from there.

I've seen those carbs have anywhere from 1/4 to 1&1/4 turn out from the factory back in the days when they were new.

Check your fuel design level in each carb. I'm not talking about float height but the amount of fuel in each bowl.

That's cheked with a guage that screws into the drain hole on the float bowls. Check the service manual for instructions.

Trim the ends of the coil wires just enough to expose some good, clean copper and test your plug caps for resistance.

Check to see how many volts you're getting to the coils. FORGET THAT STUPID REALY MOD and fix your wiring if voltage is low. DON'T EVEN GO DOWN THAT ROAD WITH INSTALLING A RELAY TO CORRECT LOW VOLTAGE...READ THAT TWICE IF NEED BE... :laugh:

If voltage is low:

Clean your all your grounds.
Spray out your switches with brake klean and wd40.
Clean all your electrical bullet connections.

In short, bring the wiring back up to spec by making certain there's no corrosion in the connectors.

That, a valve adjustment and a carb synch should get the bike operating reasonably well. You may have to play with the carbs for a while to nail the fuel curve...

You actually make a great score with the bike. Having it bone stock to start with is actually a PLUS IMO...

Larry C

not trying to be a dick, but you might be the guy who got done good...those carbs look like 26 mm vm (stock)...stock coils....if you pull the cams, you can measure the base circle vs bottom of base circle to lobe tip and find out what you have....if they measure .320 or so,you have stock cams and at that point you can probably guess why you have decent arm sockets....probably stock bore too...iirc, in the day 1045 was a first overbore, 1075 was next.....like i said, gramps might have worked ya.....i m sure the more knowledgable will weigh in.....

Thanks Larry.

The bike runs strong, it feels just like the kz1000 1977 standard A1 model I owned new back in 1977-1981.

When I rode it I was expecting a real get-up-and-go horse because of the 'hotter cams and 1137cc kit.'

Instead, when I rode it, the bike felt *exactly* like my 1st kz1000, so I thought "Wow, 1137cc + cams, feels like a stock kz1000, something's wrong."

NOPE. Nothing is wrong. It *IS* a stock kz1000.

So besides the electrical stuff you mention, there's not must left to do except design fuel level, and I bought off eBay a special tool to do just that which I'll get to directly.

But in reality the bike runs like a strong stocker.

In actuality I *wanted* a stock bike, since if I decide to sell it, a stock bike is *always* more appealing to a buyer than a heavily-modded one.

Thanks for your electrical tips.

Can measure the cams with them in the motor

newOld_kz1000 wrote:

1978 kz1000 A2, standard edition...pulled the valve cover gasket tonight to check the valve clearance...The valve clearance is fine -- I couldn't even fit a .1mm feeler gauge at all between the cam lobe and the shim after lining up the marks etc. as per the FSM....

couldn't even fit a .1mm feeler gauge at all between the cam lobe and the shim after lining up the marks etc. as per the FSM

Am not quite understanding this statement.

The valves are supposed to have 0.05mm~0.10mm clearance measured between the lowest part of cam lobe and the shim.

What marks are being lined up?

I just point the high end of cam lobe away from the shim and then attempt inserting various size feeler gauges until finding the thickest one that goes in, which is the size of the gap that's supposed to be 0.05~0.10mm.

If the .1mm feeler gauge doesn't fit, what thinner size does fit? If less than 0.05mm, a thinner shim is needed to achieve correct clearance.

Am maybe misinterpreting something here. :S

Good Luck!

keith1 wrote:

not trying to be a dick, but you might be the guy who got done good...those carbs look like 26 mm vm (stock)...stock coils....if you pull the cams, you can measure the base circle vs bottom of base circle to lobe tip and find out what you have....if they measure .320 or so,you have stock cams and at that point you can probably guess why you have decent arm sockets....probably stock bore too...iirc, in the day 1045 was a first overbore, 1075 was next.....like i said, gramps might have worked ya.....i m sure the more knowledgable will weigh in.....

He had no reason to b.s. me about the mods. He gave away this bike for free and it's on the road, running strong, 140psi in the bores, stock carbs/airbox (mostly) and electronic ignition, new battery, cleaned out carbs with all stock stuff except a street-baffle 4-into-1 Kerker pipe.

He didn't even mention the mods until I was loading it into my truck. When he mentioned the big-bore kit and cams, I was uneasy about that because I didn't want any more risk in this 'free' bike than just putting in a new battery, rebuilding the brake calipers, and cleaning the carbs. I knew it was going to cost me at least $50 for a new battery, probably $50-$75 for caliper rebuild kits, and then the hassle of disassembling the carbs.

Plus with a 31-year-old bike that's been sitting for 10-12 years, maybe the electronics stuff will need replacing. I thought "Great, he waits until I'm loading it on my truck to tell me he tweaked the motor like a 21-year-old kid. Just great."

I am glad to have discovered it's in stock trim. But I wish I knew the full story about who screwed the guy and how people can do that.

Patton wrote:

newOld_kz1000 wrote:

1978 kz1000 A2, standard edition...pulled the valve cover gasket tonight to check the valve clearance...The valve clearance is fine -- I couldn't even fit a .1mm feeler gauge at all between the cam lobe and the shim after lining up the marks etc. as per the FSM....

couldn't even fit a .1mm feeler gauge at all between the cam lobe and the shim after lining up the marks etc. as per the FSM

Am not quite understanding this statement.

The valves are supposed to have 0.05mm~0.10mm clearance measured between the lowest part of cam lobe and the shim.

What marks are being lined up?

I just point the high end of cam lobe away from the shim and then attempt inserting various size feeler gauges until finding the thickest one that goes in, which is the size of the gap that's supposed to be 0.05~0.10mm.

If the .1mm feeler gauge doesn't fit, what thinner size does fit? If less than 0.05mm, a thinner shim is needed to achieve correct clearance.

Am maybe misinterpreting something here. :S

Good Luck!

I line up the 180 degree opposing lines on the chain wheels of the cams exactly like the photograph does in the FSM, page 15, photograph B9 (this is Factory Shop Manual with part #99924-1006 01 on the back cover, and a green 1978 kz1000 A2 on the front cover). Then I put my .10mm feeler under the bottom of the cam lobe (the side that is 180 opposite the 'striker' part of the cam lobe) -- and my .10mm feeler gauge will not slip in there. I'm expecting with a bike's mileage and age that there would be excessive clearance, ie. more than .10mm. But there's not.

However -- your point is "Okay, the shim's not out of range on the 'too thin due to wear' side of the spec -- but is the shim 'too thick due to improper shim' ??"

I'll find out tomorrow after I buy a feeler gauge that has thinner feeler leafs than my current gauge, whose thinnest feeler is .10mm.

newOld_kz1000 wrote:

I'm expecting with a bike's mileage and age that there would be excessive clearance, ie. more than .10mm. But there's not.

However -- your point is "Okay, the shim's not out of range on the 'too thin due to wear' side of the spec -- but is the shim 'too thick due to improper shim' ??"

When you have wear the tolerance gets smaller not larger. Sounds backwards but when the seat wears the valve stem raises which makes the clearance smaller. So you have to use a thinner shim to make more clearance. Does this make sense?

New/old. As valves/seats wear, clearance goes away. Valve seats widen, valves develop grooves and travel deeper into seats. not vice versa. .001 may as well be NO valve clearance. adjust...Bore size... Pha...If compression #'s are within spec. and you don't process oil, ride it. the difference between a stocker and a "big bore" is usually @ 7-12 HP. Flowed heads/cams/carbs yield more (IMHOP}. I reserve arm-pulling acceleration to bikes which deliver at least 130 hp. or better. measure your cams from base circle to max lift before discarding, Cam manifactuers were plentiful in the day, Just because they never made the "big time" doe'snt make 'em bad. Lift and duration are compromises, fine tuning and flowing even more so. thus the life of drag racers for the last 20 or so years. luck g

Okay, I get the 'clearance goes away as valve seats wear' -- so it's even more important that I do what I've planned for tomorrow, which is to buy a set of thinner feeler gauge leafs, Kragen Auto Supply don't let me down! Else I'll have to wait until Monday to find a real automotive tools supply store.

I know I have less than .10 mm of clearance. The manual says the acceptable range is .05mm to .10mm -- so after I measure tomorrow, if I have less than .05mm clearance -- DOES IT MEAN I NEED TO GO TO A THINNER SHIM or get a valve job?

28,500 miles on the bike.

newOld_kz1000 wrote:

...if I have less than .05mm clearance -- DOES IT MEAN I NEED TO GO TO A THINNER SHIM or get a valve job? 28,500 miles on the bike.

Most likely just needs a thinner shim.

Good Luck!