Fouled lobes?

  • missionkz
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Fouled lobes?

10 Jul 2016 18:20 - 10 Jul 2016 18:34
#734507

Not liking some of the scoring on my cam lobes.
Under 45,000 miles and doesn't seem like I should be seeing these.
Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado
Last edit: 10 Jul 2016 18:34 by missionkz.

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Re: Fouled lobes?

10 Jul 2016 18:29
#734509
Stock cams? What do the shims look like?
Steve

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  • missionkz
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Re: Fouled lobes?

10 Jul 2016 18:33 - 10 Jul 2016 18:37
#734513

Intake cam.
Same one with the bent valve earlier this week,
Two lobes scored and the two shims are scored also.
Stock, these are my original 77" cams.
This shot is lobe #3 intake.
You have zoom in to get a good sense of the scoring.
Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado
Last edit: 10 Jul 2016 18:37 by missionkz.

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Re: Fouled lobes?

10 Jul 2016 18:44
#734515
With your motor, some "drop in" mid range cams will do the bike good.
Steve

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  • Nessism
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Re: Fouled lobes?

10 Jul 2016 18:45 - 10 Jul 2016 19:10
#734516
Those cams will run fine but I'd monitor the wear carefully. Some of Kawasaki's rocker arm engines ate their cams and the engines seemed to run well regardless. Such wear is a good reason to run good oil; something with a good bit of ZDDP.
Last edit: 10 Jul 2016 19:10 by Nessism.

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Re: Fouled lobes?

10 Jul 2016 18:53
#734517
Nessism wrote: Those cams will okay fine but I'd monitor the wear carefully. Some of Kawasaki's rocker arm engines ate their cams and the engines seemed to run well regardless. Such wear is a good reason to run good oil; something with a good bit of ZDDP.
My over active mind has me thinking higher friction with these cam lobes and a potential "spit out" shim at +8500 rpm!!
Been using Rotella 10-40 for the last two- three years now and 20-50 Castrol GTX for the first 35,000 miles.
Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado

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Re: Fouled lobes?

10 Jul 2016 19:12
#734523
missionkz wrote:
Nessism wrote: Those cams will okay fine but I'd monitor the wear carefully. Some of Kawasaki's rocker arm engines ate their cams and the engines seemed to run well regardless. Such wear is a good reason to run good oil; something with a good bit of ZDDP.
My over active mind has me thinking higher friction with these cam lobes and a potential "spit out" shim at +8500 rpm!!
Been using Rotella 10-40 for the last two- three years now and 20-50 Castrol GTX for the first 35,000 miles.

I wouldn't worry about spitting out a shim. Biggest worry, I think, would be possible extra metal debris in the oil

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Re: Fouled lobes?

11 Jul 2016 21:36 - 11 Jul 2016 21:37
#734642
I pulled all 8 valves out and replaced all the valve guide seals today.
I forgot what pain it is to pick those seals off the guide without the right tool.
Yes, I used those pale blue/green Viton seals you all rave about.
Even though the old ones had less the 4000 miles on them.
(I replaced the ones I put in last year in the spring.)
Those were the black ones from Z1.
Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado
Last edit: 11 Jul 2016 21:37 by missionkz.

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Re: Fouled lobes?

11 Jul 2016 22:29
#734647
That's the kind of lobe scoring seen in cases where the oil was too low on ZDDP.
1979 KZ-750 Twin

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Re: Fouled lobes?

12 Jul 2016 12:03
#734700
That is spalling. There were lots of bikes that did this back in the 70's and 80's. Use a good oil and if it gets worse change them out.
1980B4 1000
1978 Z1R
1978 B3 750

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Re: Fouled lobes?

12 Jul 2016 14:54
#734711
I have good pair of 78 KZ1000 cams that are well within specs.
Looking them over with my lens shows none of that galling. I'll probably use them.
Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado

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