Topic: Top end rebuild advice

[mook32540]

Hello,

My name is Mike and I've been reading this forum for the past year (about 10 months before actually buying my first SOHC) and have found it really helpful. A couple months ago I picked up this 750 K7 with the hopes of bringing it up to the 21st century.

I started with a 3000 mile tune up and carb rebuild since the previous owner said it hadn't started in a couple years and before that had trouble idling. So I get to the taper valve adjustment portion of the show to fine the screw and nut completely absent from #2 intake side. At that point I decide to not try and start it to see if it would turn up (it didn't) so long story short I checked the compression and on all 4 they were right around 100 psi but went up to 160 after a T of motor oil. I figured now is a good time for a top end rebuild so took it to a highly rated mechanic near Ann Arbor (I live in Michigan).

I have had bad experiences with mechanics in the past which have led me to work on my vehicles myself which brought me to the SOHC world but I am realistic about my skill set and don't feel comfortable trying to rebuild an engine just yet. Could someone do me a solid and explain what this mechanic should be checking and replacing and how much time it should take to do so (labor hours etc) I'm afraid of being charged $1000 only to find out he just replaced a head gasket (extreme circumstance but not out of the realm of possibility). I'd like to be well informed of what goes into a top end rebuild so I can ask educated questions when things get moving. Thanks.


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[mook32540]

Forgot to post the pic.



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[BPellerine]

I think I would try to find the adj screw and nut by looking in the tappet  covers and fishing around with a magnet before I took it apart,you seem to have even compression,drop the oilpan to see if there is any metal in there.bill

[mook32540]

I think I would try to find the adj screw and nut by looking in the tappet  covers and fishing around with a magnet before I took it apart,you seem to have even compression,drop the oilpan to see if there is any metal in there.bill

Thanks Bill. I poked around the best I could with a magnet after I discovered it missing with no luck. Dropped the pan only to find a small amount of metal shavings. Nothing I'd think would amount to a nut and a screw. Like an idiot I just tossed the shavings (I'm new at this) so I couldn't tell you if they were aluminum or steel.


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[BPellerine]

a top end job would include,
rings,or pistons if required
bores checked for wear
cylinder head checked for warpage
guides checked for wear,and replaced if necc
valves checked for pitting and wear,
new valve seals at a minimum,
maybe you could just do the head,
or you could pull the engine yourself and look under the valve cover.bill

[mook32540]

a top end job would include,
rings,or pistons if required
bores checked for wear
cylinder head checked for warpage
guides checked for wear,and replaced if necc
valves checked for pitting and wear,
new valve seals at a minimum,
maybe you could just do the head,
or you could pull the engine yourself and look under the valve cover.bill

Thanks Bill, really appreciate you taking the time to share some advice. It's in the shop now so I'm glad I have a list to go on. Keep an eye out in the future for som build pics when I get it back.


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[calj737]

If the compression jumps to 160 with a bit of oil, I wouldn’t rush to rebuilding it. It’s not uncommon for a motor that has sat a while to be low. Definitely want to locate the adjuster screw, which may require pulling the cover altogether.

[BPellerine]

yes the screw can lodge itself down around the bottom of the valve spring and not be seen without taking the cover off.bill