Author Topic: Weird topend noise cb750 with pics.. (Read 2171 times)

754 · « **on:** September 05, 2015, 01:21:43 PM »

I put 200 miles on this on this on Wed, 60-70 mph thru steep mountain passes.
At the end of the day it had gotten a lot louder..
I decided. To cut the frame and pull the tappet cover..

Does this look bad ? ? ?

Trad · « **Reply #1 on:** September 05, 2015, 01:25:34 PM »

Those lobes are pooched, it looks like the bearing surface is all scored too. Oil starved looking results.

goldarrow · « **Reply #2 on:** September 05, 2015, 01:26:32 PM »

Yes, look bad. Lack of oil up top?

BPellerine · « **Reply #3 on:** September 05, 2015, 06:34:57 PM »

does this look bad,a little humour there frank??bill

Garage_guy_chris · « **Reply #4 on:** September 05, 2015, 06:43:22 PM »

meh nothing wrong with that. Throw it back in change the oil to 85w140 gear oil. adjust the tappets to 1/4" clearance and enjoy!

enwri · « **Reply #5 on:** September 05, 2015, 07:08:53 PM »

VTEC?

jonda500 · « **Reply #6 on:** September 05, 2015, 10:16:22 PM »

I'd love to see the rockers that went with that camshaft- that's the worst one I have ever seen! John

mrbreeze · « **Reply #7 on:** September 05, 2015, 11:17:45 PM »

If ya keep running it like that it will wind up looking like Garage Guy Chris's piston!!

PeWe · « **Reply #8 on:** September 06, 2015, 03:16:30 AM »

Metal burrs all over the engine or at the top only?
Maybe time to pull engine and repair it all, find the reason for oil problem that might have caused more damage. Crank, rod bearings...?

754 · « **Reply #9 on:** September 06, 2015, 07:53:30 AM »

Changed cam, rockers, towers..runs like a swiss clock..

Old Scrambler · « **Reply #10 on:** September 06, 2015, 09:19:02 AM »

But will the Swiss clock be running after a few hundred miles?

754 · « **Reply #11 on:** September 06, 2015, 10:38:05 AM »

It better, got around 500 miles to ride back..

PeWe · « **Reply #12 on:** September 06, 2015, 11:33:58 AM »

Tick-tack-tick-tack-tick-tick-crack!

Henning · « **Reply #13 on:** September 06, 2015, 01:23:32 PM »

So, you just happened to have a spare cam, rockers etc. in the toolkit under your seat?

:-)

754 · « **Reply #14 on:** September 06, 2015, 04:38:54 PM »

Had to drive 390 miles round trip in a cage...to my stash..
Cut frame tore down, and fixed it Friday..
Did not remove carbs, moved coils.around, without unclipping the wiring..
Most of the debris settled under the cam tower, the pocket on outboard side, and the depression by the front oil drain..... A bit of stuff in filter housing but. Far less than expected. ..good thing

Got 200 miles on it..running great.... Finally on the road..

seanbarney41 · « **Reply #15 on:** September 06, 2015, 05:29:31 PM »

Did you check that there is a good amount of oil getting up there?

754 · « **Reply #16 on:** September 06, 2015, 08:04:56 PM »

Yes, oiled everything but the top collar on the valve..
Rode a couple miles pulled the tappet covers on 4.. The collars were oily..
We pulled the destructor jet and cleaned it and part of the passage.. The jet looked clogged and I got some stuff out of the oilhole.

PeWe · « **Reply #17 on:** September 07, 2015, 03:08:31 AM »

Silicone used at a previous repair? Or too much case sealer that fall off? More to come and block the passage?

754 · « **Reply #18 on:** September 07, 2015, 02:29:32 PM »

I like to hope its finished that.. It better get me home..
Yeah I new by the silicone hanging off case mating surface, that this could've a possibility.. Blank, no number cases on it..

754 · « **Reply #19 on:** September 08, 2015, 07:43:28 PM »

The Swiss watch has about 575-600 me les on it and got me home....good good..

mystic_1 · « **Reply #20 on:** September 08, 2015, 08:43:00 PM »

Glad to hear you managed to RTB safely.

mystic_1

754 · « **Reply #21 on:** September 14, 2015, 10:02:17 PM »

Got 1000 miles on it now... Don't know whether to call it...
The Blue Bastarde.....or the Swiss Clock.....lol

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Author Topic: Weird topend noise cb750 with pics.. (Read 2171 times)