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Oily exhaust valve
- toadson
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It's a bit dark, but you can tell the valve is oily. What is the most likely cause... bad rings or a bad valve stem seal? The bike has around 36k miles on it, and I have no idea if it has ever been rebuilt or not. While I was in there, I checked all valve clearances and they are all in spec. All of them were at .003" except the #1 intake and #4 exhaust, which were at .002". My last compression test was done almost a year ago. The results from that were #1-160lbs #2-140 #3-140 #4-150. It wouldn't hurt to check this again, but it didn't cross my mind tonight.
I'm contemplating on removing the head and cylinder just to inspect and clean up everything. Someone put a bad paint job on this engine and it has been peeling ever since I bought it. I could also get some head work done if my valve seals are bad, or replace the piston rings if they are causing the oily exhaust valve.
I would like some input on what my next move with the bike should be. I don't mind it being off the road for a few weeks as long as I get it running how it should and looking less like a junker.
79 KZ1000 LTD. Mikuni VM26 w/ accelerator pump. 4 into 1 header. Stock intake setup. GS1100 Swingarm, My swap thread: kzrider.com/index.php?option=com_kunena&...d=5&id=210872#210872
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- Patton
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Typically evidenced by exhaust smoke from cold cranked engine, with less smoke after reaching normal operating temp.
A common usually non-critical condition.
After assuring valve clearances are okay, would perform both compression and leak-down tests to help determine general condition of top end.
Good Fortune!
1973 Z1
KZ900 LTD
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- bountyhunter
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1979 KZ-750 Twin
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- Motor Head
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- FIX UP YOUR BIKE RIGHT AND CHEAP
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Good luck.
1982 KZ1000LTD K2 Vance & Hines 4-1 ACCEL COILS Added Vetter fairing & Bags. FOX Racing rear Shocks, Braced Swing-arm, Fork Brace, Progressive Fork Springs RT Gold Emulators, APE Valve Springs, 1166 Big Bore kit, RS34's, GPZ cams.
1980 KZ550LTD C1 Stock SOLD Miss it
1979 MAZDA RX7 in the works, 13B...
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- bountyhunter
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I always wondered how that's possible. On my 750 twin, there is a fair amount of overlap at TDC. The exhaust valve is already opening and the intake is not fully closed yet. I could not find any position where both valves were fully closed. I always tried to find one to make checking valve clearance easier, but there isn't one on mine.Go and do a compression test, if low or uneven then a leak-down test to find the source. If all good you can get the stem seals off and new ones in with the head on the bike. If you have a air compressor you can hold the valves shut at TDC firing position
1979 KZ-750 Twin
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- TeK9iNe
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The valve seals shrink after they cool, and can let some of the residual oils soak into the carbon powder that accumulates on the valve back. Even a tiny little drop seeps through and it spreads all over that stuff.
Try pulling the header off hte bike right after riding it! :laugh: Seriously though, put a fan on the header, then puller off after a run and see what they look like - probally fine.
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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- toadson
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79 KZ1000 LTD. Mikuni VM26 w/ accelerator pump. 4 into 1 header. Stock intake setup. GS1100 Swingarm, My swap thread: kzrider.com/index.php?option=com_kunena&...d=5&id=210872#210872
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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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- Old Man Rock
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Maybe it's just the old eyes messing with me....
OMR
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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- Motor Head
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What you're referring to, "Quite a bit of vale over lap at TDC" is 360 degrees off of the firing position. Turn the crank around 1 more time to reach the TDC mark again, then on #1 the cam lobes should not be pushing on the cam followers/ tappets.
Same is true for your Saturn engine, you can do the stem seals in the car without removing the head.
1982 KZ1000LTD K2 Vance & Hines 4-1 ACCEL COILS Added Vetter fairing & Bags. FOX Racing rear Shocks, Braced Swing-arm, Fork Brace, Progressive Fork Springs RT Gold Emulators, APE Valve Springs, 1166 Big Bore kit, RS34's, GPZ cams.
1980 KZ550LTD C1 Stock SOLD Miss it
1979 MAZDA RX7 in the works, 13B...
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- TeK9iNe
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Maybe I'm missing it but in those images, they seem carboned not oily thus depicting a real rich configuration in the cab jetting.
Maybe it's just the old eyes messing with me....
OMR
This depends on how much time he spends accellerating, and how much time he spends cruising.
If your just making short quick blasts around town, and not cruising around at minimal throttle for hours, then the exhaust valves will tend to look somewhat "carbony", if thats a real word :laugh:
Its from the carbs tendency to richen considerably upon accelleration... and doesn't tend to clean up easily (takes long cruise times to minimise it.)
Or he's just plain too rich at idle, and lets it idle all the time for extended periods! :laugh:
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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- Old Man Rock
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What I was meaning is they don't seem "Oily" saturated in oil thus ring issues... Only carbon....
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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