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Help diagnose clacking and rough idle?
- Virii
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- I like cheese
This 77 KZ650-C1 generally runs excellent. It seems to sound fine at 1500RPM but starts to act up when I try to set the idle around 1000 (by the dash gauge the accuracy of which I haven't confirmed). Acceleration is smooth from the curb straight through the gears and all the way to freeway speed. There are no hesitations or galloping.
Some history:
4-1 exhaust was replaced with a stock set of 4-2's. Carbs rejetted to 97.5/15/3rd.
The carbs have been thoroughly cleaned and adjusted this week with the exception of the float level which I didn't change. With help in a thread in carbs, I finally found the missing puzzle pieces of what to do with the fact I have both air and pilot screws and now have those set properly.
Valves were done 500 miles ago, while the 4-1 was installed. Have not been done since.
APE manual cam chain tensioner was installed a year or two ago. I've doubled checked it this week. Loosening the tensioner doesn't increase any noise. Tighter and the engine produces a "whirring" noise.
New battery this week.
Cleaned all electrical contacts I could find.
Coil mod done and wiring rechecked this week. Have not checked voltages but didn't notice any change when the mod was originally done a year or two ago.
Has dyna ignition. Coils are black and don't appear to be marked so far as I can tell.
It has the light switch and at idle, there's a notable difference in engine sound when I turn the lights on. Engine speed reduces very slightly and actually sounds like it evens out a little (not that I'm on a witchhunt or electrical problems but thought it might be relevant)
Any thoughts or directions to look in would be greatly appreciated!
Tess: 1977 KZ650-C1. VM24, 97.5/15/3rd. Dyna-S. Stock exhaust, coil mod performed, BR7EIX.
Angel: 1982 GPz550. Stock. DR8EIX.
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- MFolks
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Some light oil like sewing machine or 3-in-one will work fine for lubrication.Apply the oil to the pivot areas of the advancer and where the springs attach.
New sparkplugs,sparkplug caps and wires all will help in low rpm problems.
1982 GPZ1100 B2
General Dynamics/Convair 1983-1993
GLCM BGM-109 Tomahawk, AGM-129A Advanced Cruise Missile (ACM)
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- Old Man Rock
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Adjust your idle between 1000-1200 and confirm the difference!
1976 KZ900-A4
MTC 1075cc.
Camshafts: Kawi GPZ-1100 .375 lift
Head: P&P via Larry Cavanaugh
ZX636 suspension
MIKUNI, RS-34'S...
Kerker 4-1, 1.5" comp baffle.
Dyna-S E.I.
Earls 10 row Oil Cooler
Acewell 2802 Series Speedo/Tach
Innovate LC1 Wideband 02 AFR meter
Phoenix, Az
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- Krusty_47
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1976 KZ900 A4
1980 KZ1000 G1
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- Patton
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Proper engine tune (ignition, valves, camchain tension, and dynamic carb sync, etc.) should allow the lowest possible idle rpm before getting to the crunching sound.
Good Luck!
1973 Z1
KZ900 LTD
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- BSKZ650
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I think you may be trying to idle it too low also, the tach's are not acurate although you said you checked it, Ilde it where it runs the best and does not bog when you take off
77 kz650, owned for over 25 years
77 ltd1000, current rider
76 kz900, just waiting
73 z1,, gonna restore this one
piglet, leggero harley davidson
SR, Ride captian, S.E.Texas Patriot Guard Riders.. AKA KawaBob
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- 650ed
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1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- Bluemeanie
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OMR, how did you "freeze" a pic from the video??
1980 KZ650F1, Bought new out the door for $2,162.98!
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- Old Man Rock
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Simple... Pause the video on the frame you want(scroll back and forth) then DON'T use cntrl/alt/print screen keys on your keyboard... Just Print Screen Key only!
Then paste into paint or other imaging programs.... Whola!
1976 KZ900-A4
MTC 1075cc.
Camshafts: Kawi GPZ-1100 .375 lift
Head: P&P via Larry Cavanaugh
ZX636 suspension
MIKUNI, RS-34'S...
Kerker 4-1, 1.5" comp baffle.
Dyna-S E.I.
Earls 10 row Oil Cooler
Acewell 2802 Series Speedo/Tach
Innovate LC1 Wideband 02 AFR meter
Phoenix, Az
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- timebomb33
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1973 z1 2-1974z1-a,2-1975z1-b dragbikes1015cc+1393cc, 1977kz1000,1978kz1000,1981kz1000j, 1997 zx-11, 2000 z12r,1428turbo nitrous pro-mod and a shit load of parts thats all for now leader sask.,CANADA
I THINK MY POWERBAND BROKE
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- Virii
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- I like cheese
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I did put some gauges on and synced the carbs (cheap set of dials off eBay). The bench sync surprisingly got it extremely close and I only needed some minor adjustments to get balanced. While diagnosing, I also put in new plugs but have never changed the wires and caps which go straight into the housing of the coils.
I've just gone out to check. I can confirm that the advance appears to return nicely but I gave it a little oil just for good measure. The sound doesn't appear to change with the clutch or gearing. Visually the holders looked okay but I did a quick spray test just to be sure and didn't notice any behavioural changes.
Raising the idle very carefully, I can say that it's just barely over around 1200 or so (eyeballing by the dash gauge which I have no way to verify) that the engine finally evens out and the sound pretty much goes away entirely which seems to be expected so I think I'm going to take that as my cue to relax.
Thank you everybody for your knowledge and input. My fairly mechanically green mind had visions of pieces of loose parts shredding around, waiting to ruin my day.
It's very reassuring to hear from people who know the machine well!
Tess: 1977 KZ650-C1. VM24, 97.5/15/3rd. Dyna-S. Stock exhaust, coil mod performed, BR7EIX.
Angel: 1982 GPz550. Stock. DR8EIX.
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- TeK9iNe
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- What did you do!?!
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APE manual cam chain tensioner was installed a year or two ago. I've doubled checked it this week. Loosening the tensioner doesn't increase any noise. Tighter and the engine produces a "whirring" noise.
The whirring is normal, and closer to proper operation.
Sounds to me like cam chain...
I have to adjust my tensioner every season. Several times in three months after putting in a fresh cam chain.
With a manual tensioner, it should be turned all the way in by "finger pressure" only, with the engine at TDC.Turn the engine over, then repeat till tensioner will not go in farther. Remember, light finger pressure only! Then turn it out only about 1/8th turn, then tighten lock nut.
Hope it isn't somethin else serious!
Cheers!
Motorcycle Shop Owner/Operator
79 Kawie Z1000 LTD
81 Kawie Z1000 CSR
83 Honda VT750C A
85 Kawie GPZ900 A2
86 Zukie GS1150 EG
93 Yamie XV1100 E
Lucky to have rolled many old bikes through my doors
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