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1Back to top Go down    Valve Clearances on Mon Dec 18, 2017 10:29 pm

GF Wollongong

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Before I can properly tune my K100RS 1983, I am going after the valve clearances.

Unfortunately, they are all too tight (gap to small). On youtube, Michael Lovitch (?) uses a valve shim cup from a VW to hold his K75 shims as he grinds them down on an disc sander.

Any thoughts on this approach? Where do I get the cup from? Should I buy new? When ordering new shims, is my desired shim based on the existing shim and a few calculations X 8 shims?

Also, the cam shaft is showing some cams as shiny and others dull grey. To me this means they are not working / getting rubbed like the shiny ones. Any thoughts / experiences?

If I get a result here, maybe adjusting the idle screw will finally work (unresponsive at present using a carb tune). End goal is reducing vibrations at 4000+

Will do compression test after shims shorted.

Thanks 

Guy

    

2Back to top Go down    Re: Valve Clearances on Tue Dec 19, 2017 2:11 am

charlie99

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lots of posts about tuning the throttle bodies in the forum guy

if you haven't already cleaned up the bypass ports and removed the needle and seat of the air bypass  screws ,  carbi cleaner and pipe cleaners work well cleaning the ports through (everything below the butterflies suffers from blow back of fuel -carbon build up ) and are often found to be blocked on a "new to me bike"

but forget them all till you have clearances sorted




I wouldn't attempt the shaving of a shim down to thickness  I believe they are hardened on each face  so shaving them would-may  remove the hardened layer of metal.

a friendly head maintenance shop did the same for me on two of the shims I required doing on the car motor refurb a couple of years ago , after just a few hundred kilometers I found that they were showing really noticeable wear marks on the shaved surface

specialty shims I believe do the right sizes  and thicknesses , and aren't expensive at all really , so pull the shims on the tight ones and do the calculations for the correct size first ..be methodical and very detailed about what you find and position  ...  you may find that you have a closer size of one from a different location ?

perhaps some of the members on here could help with the right sizes as well ?

perhaps also the cam followers are stuck and not rotating properly anymore (more likely as the shims are too tight not allowing for proper rotation patterns ) to show even wear around the shim faces , and thus the cam face
in any case  perhaps new oil may help this after the adjustments , I know I would be putting in diesel oil to run her in again and clean out all the gunk accumulated over the years , which I will be doing , hopefully as soon as I move to new premises  and more engine work to come .


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cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
    

3Back to top Go down    Re: Valve Clearances on Tue Dec 19, 2017 5:42 am

MartinW

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Don't grind them. Some Yamahas' and possibly Suzuki's have the same size shim. Also some dealers will exchange shims for a fee. Just check exchange shims for wear, goods shops normally bin the dodgy ones.
Regards Martin.

    

4Back to top Go down    Re: Valve Clearances on Tue Dec 19, 2017 7:07 am

charlie99

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Kawasaki klr 650 ? shims fit ...I swap local at the service centre   $5.00 per shim


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cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
    

5Back to top Go down    Re: Valve Clearances on Tue Dec 19, 2017 9:15 am

Laitch

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@GF Wollongong wrote: On youtube, Michael Lovitch (?) . . .
Using michaelovitch—probably a Russian patronymic or surname—is the quickest way to find his vids.


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1995 K75T 68,000 miles
    

6Back to top Go down    Re: Valve Clearances on Tue Dec 19, 2017 10:56 am

RicK G

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Do NOT grind the shims you WILL regret it. If it needs thinner shims the head needs rebuilding. The early heads were designed to use leaded fuel and will often recess the valves causing the gap to close.
Best advice is to get a post 85 head with the stellite valve seats and better valves. It would be the cheaper option than a rebuild.


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"Every normal man must be tempted, at times, to spit upon his hands, hoist the black flag, and begin slitting throats."  from Mencken's 1919 Prejudices

Bikes 1993 K1100 LT, 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 for now
    

7Back to top Go down    Re: Valve Clearances on Tue Dec 19, 2017 3:49 pm

GF Wollongong

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Thanks for the replies

So I guess it's "put the angle grinder away"...

Have already removed and cleaned the throttle bodies and especially under the butterflies. Also removed the idle screws and cleaned these out.

Will be on the look out for a later engine. Will check parts engine for suitability for swapping heads.

But for now it's ride it and put the valve saver in. Xmas is upon us all and there are jobs aplenty to take us away from our favourite distractions.

Will post an update when I have had a result.

Regards

Guy

    

8Back to top Go down    Re: Valve Clearances on Tue Dec 19, 2017 4:05 pm

MartinW

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Guy I would still check the shims and determine whether it might be possible to insert thinner OEM shims. It is a longshot but if you don't check them you might be chasing a new head or engine prematurely. There is always a slim chance.
Regards Martin.

    

9Back to top Go down    Re: Valve Clearances on Tue Dec 19, 2017 4:44 pm

Andrew2

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I know where there is/was a motor for $250.


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1987 K100RS
    

10Back to top Go down    Re: Valve Clearances on Tue Dec 19, 2017 5:59 pm

GF Wollongong

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Andrew

Have PMd you

G

    

11Back to top Go down    Re: Valve Clearances on Wed Dec 20, 2017 1:50 am

Point-Seven-five

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I would check with a local machine shop for the cost to refresh your old head.  New seats, lapped valves, valve guides and seals and your engine will be good for another 200,000 miles.  I would guess that it can be done for not much more than what a good used head will cost if you add in the shipping cost.  And then you will still have an old head with miles on it.


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Present:
1994 K75RT
1994 K75S
1992 K100RS

Past:
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

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