What the?... can anyone tell me why this happened

hi Zeds,
I am a new '79 KZ1000 owner. Bought this bike a couple weeks ago and have been slowly cleaning it up. PO tells me he had the carbs cleaned, rebuilt and jetted by a specialist on the mainland. But it ran like shit - only capable of about 4500rpm in any gear and I was pretty sure this was a carb issue.

There is a leak at one of the intake boots and #1 and #4 dribble from the overflow when parked.I rode it daily to work (4 miles, max 50mph) and it could barely do that. Mileage was 30 mpg. Before taking the carbs off and fiddling with them, I thought I'd replace the points, set timing and wait for my new pipes to arrive and get fitted. I have a few other bikes so was in no hurry. Also wanted my mechanic to re-shim the valves first.

Getting to the good part... I noticed the pod filters were a bit old so bought a new set. The old pods look like they had been sucked inwards somehow - instead of being conical, the edges were concave. Anyway, I fitted the carbs and rode to work this morning. The old girl ran like a rocket! At about 4000 rpm, instead of stumbling and carrying on, it hit some kinda 2 stroke power band and rocketed to 7000 rpm. I was not expecting this and almost fell off the back of the bike! I may have wet myself just a little bit...

Although rather delighted, I'm also more than a bit curious as to why? Can anyone help me here? Any thoughts appreciated. Mechanic reckoned it was running lean before, but I thought maybe rich. Plugs were not black or white but a mid brown. What the f#%K has caused this rather nice change in behaviour? Also, do these monsters have a power-band like response in this rev range? I rode a Suzuki GS1000S for years and it was not at all like that!

Possibly a backfire melted the pods(If they were the foam type),but if they are the K & N gauze type, I have no idea of how they changed shape.

The k&ns could of just been really old and dried out,maybe replacing them allowed whatever was stuck in the carbs to get sucked out.
Is the motor stock internally,maybe differant set of cams that come to life around 4,000?
Ive got an old 1170 motor wrapped up in my barn that would run like an absolute dog till about 6500 when it would hit its happy spot and suddenly come to life and try to toss ya like a bull! :sick: :woohoo:

No idea of the engine internals and the pods were just standard gauze type. I replaced them with equally cheapish gauze filters. The change this brought about was surprising and... well... rather nice. The reason is something I'd like to know. BUT - the huge kick this old girl now has when everything seems to be running right has given me a new-found respect - and love for this engine.

WOW! I've ridden big quick bikes before. A Suzuki GS1000 Wes Cooley Special was no slouch back in the day (and probably even now). But this MOFO just scares the living sh#t outta me. My frigging legs were waving around in the slipstream - it was all I could do to hang on! (note to self... gotta replace those police bars with some flat ones so I have 1/2 a chance of hanging on).

:woohoo: :woohoo: :woohoo: :woohoo: :woohoo:

I wonder if the old pods had gotten wet and sort of mushed together then dried that way blocking air flow? Ed

I wonder if the old set of pods had covered the Air Bleeds at the Airhorn/ Bellmouth of the carb, causing the excessive rich running?

Motor Head wrote: I wonder if the old set of pods had covered the Air Bleeds at the Airhorn/ Bellmouth of the carb, causing the excessive rich running?

X2

u may have some aftermarket cams in there. they can cause a sweet spot like that .

Maybe the old pods were actually the paper type, and not gauze. Then if someone oiled them, they would be clogged. This would also explain the caved-in look, and 4500 RPM limit.

Paper pods look almost exactly like the gauze type, but are much cheaper, disposable, and require no maintenance.

hi Zeds,

I'm still not sure what the issue was. Attached is an image of one of the pods. BUT - I am now very much in love with this bike. She seems to have 2 personalities - one below 4000 rpm where she is sedate, agile, graceful and restrained, then the devil comes out at around 4500-5000. At this point, hang on, don't wet yourself, brace (cos otherwise you will pop a disc in your neck) and she will go like the clappers! I'm too old for this but once over the 4500 limit, she turns into a beast, I have a smile frozen on my face and I just wanna go real real fast. One scary bitch!

Maybe the cams are after-market. Whatever, its a real rush!

[attachment:1]IMG_3541.JPG[/attachment]

dl.dropbox.com/u/17898942/IMG_3541.JPG

loudhvx wrote: Maybe the old pods were actually the paper type, and not gauze. Then if someone oiled them, they would be clogged. This would also explain the caved-in look, and 4500 RPM limit.
Paper pods look almost exactly like the gauze type, but are much cheaper, disposable, and require no maintenance.

this caught my eye +1

folks hold them like a grip to keep them from coming off as they tighten the hose clamps,as they tighten the filters rubber boots slip off over and over and over...so they grip the filter and push em while they clamp...that is how they get like that imo

MFolks wrote: Possibly a backfire melted the pods(If they were the foam type),but if they are the K & N gauze type, I have no idea of how they changed shape.