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1Back to top Go down    Engine case and cover tolerances on Fri Apr 06, 2018 1:52 am

FreyZI

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Left the K sit all winter and did a bit of work on the Guzzi instead, but mostly just mourned the crappy weather in central Pennsylvania (still mourning). I'm getting reinvigorated to finish this project and get the old girl back on the road. So, today I drained the oil so I can address a leak.

I did the whole top end (er, left side end) in the fall (an effort to address smokiness). Upon reassembly, I noted that there was a bit of an offset between the engine case and the front cover -- not much, maybe a fingernail's thickness. Despite a liberal spreading of ultra black, I ended up with an oil leak -- probably several drops a day -- apparently right where that offset is, below the timing chain.



Now, admittedly, I rushed and tightened down the case cover before letting the ultra black cure a bit. So, the questions: Is this gap anything to worry about? Should I just give it another go with the ultra black and allow proper time for cure before tightening down the cover, or do I need to do something more involved, like filing?

Cheers,

Frey

    

2Back to top Go down    Re: Engine case and cover tolerances on Fri Apr 06, 2018 2:45 am

TacKler

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The gap is just how it is made and the sealant you applied is what is required. However the manual says to apply the bolts to the correct torque values as this avoids distorting the seal.

However, looking at the photo, the bolt to the left of the indicated area looks to be loose. Could this be the problem?


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3Back to top Go down    Re: Engine case and cover tolerances on Fri Apr 06, 2018 2:55 am

Laitch

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@FreyZI wrote:Despite a liberal spreading of ultra black, I ended up with an oil leak -- probably several drops a day -- apparently right where that offset is, below the timing chain. . . .allow proper time for cure before tightening down the cover . . .
Curing isn't the problem. If the surface is not perfectly free of oil, you'll have problems. Did you reuse the old gasket?

Like TacKler, I was wonder what was happening with that screw, too.


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1995 K75T 68,000 miles
    

4Back to top Go down    Re: Engine case and cover tolerances on Fri Apr 06, 2018 4:12 am

Point-Seven-five

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A trick we use in the boatyard is to tighten down on sealant in two stages.

Put the sealant on the surface you want to seal and then assemble, tighten the fasteners only enough to get a bit of sealant to squeeze out all the way around the joint, then stop.

Let the sealant cure for at least a day, longer if possible, then tighten to the proper torque.

What you have done is used the sealant to form a thick gasket that is compressed when it has hardened enough so that it doesn't all squeeze out.


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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
    

5Back to top Go down    Re: Engine case and cover tolerances on Fri Apr 06, 2018 5:30 am

RicK G

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The crankcase end cover probably has been put on incorrectly which makes the other end sit out a bit the best way is to remove the crankcase cover then position the front cover so the ends are flush then once the front cover is tight the crankcase cover and cam covers can be put on without that uneven surface. Just a very small dab of sealant then tighten the cover bolts finger tight, let the sealant cure the tension the cover bolts to 8-10ft/lb.


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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 & 1976 SR 500 Yamaha for now
    

6Back to top Go down    Re: Engine case and cover tolerances on Sat Apr 07, 2018 2:33 am

FreyZI

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Indeed that bolt was loose. Another duh moment in this project. I'll try re-aligning the timing chain cover before putting the valve cover back on. So, what's the best way to get the old ultra black and the oil off the gasket so I can get a good seal?

    

7Back to top Go down    Re: Engine case and cover tolerances on Sat Apr 07, 2018 12:15 pm

robmack

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Careful scraping with razor blade to get the large portions off being very careful not to gouge or scratch the surface. Then follow that with a cloth wiping with acetone. You want to remove all remnants of old sealant so that will take time and effort. Don't be tempted to rush the job and use abrasive scrubs.


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Robert
1987 K75 @k75retro.blogspot.ca
2011 Moto Guzzi V7 Racer
http://k75retro.blogspot.ca/
    

8Back to top Go down    Re: Engine case and cover tolerances on Sun Apr 08, 2018 8:52 pm

FreyZI

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@robmack wrote:Careful scraping with razor blade to get the large portions off being very careful not to gouge or scratch the surface. Then follow that with a cloth wiping with acetone. You want to remove all remnants of old sealant so that will take time and effort. Don't be tempted to rush the job and use abrasive scrubs.
Carefully cleaned.

Questions: Per Haynes manual, "Apply smear of sealant to stick in cover groove." Is there a sealant that's easily removed the next time I have the cover off? When they say, a "smear", what exactly is that? Is it really necessary?

    

9Back to top Go down    Re: Engine case and cover tolerances on Sun Apr 08, 2018 9:07 pm

Laitch

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@FreyZI wrote: When they say, a "smear", what exactly is that? Is it really necessary?
It's a smidge that's been spread out by downward and lateral pressure. As far as being really necessary, don't do it and let me know. I'm a slave to instructions.


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1995 K75T 68,000 miles
    

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