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Engine seized

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coolmg
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Engine seized

Post by coolmg » Tue May 07, 2019 7:43 pm

Engine seized while running. Took my CA77 for a test ride, and it ran fine for 26 miles, within a 1/2 mile of home running about 30mph the engine all of a sudden seized. With a wrench on the crank nut the engine will turn very hard. Removed the clutch so as to turn only the engine, very hard to turn. Removed plugs oiled the cylinders same problem. Drained oil and found nothing like metal in the oil, it was fresh oil and looked like it. Prior to the engine stopping I did not hear any tell tail sounds, it sounded great. Any suggestions would help please.

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G-Man
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Re: Engine seized

Post by G-Man » Wed May 08, 2019 12:34 am

Bad luck.

Have a look at the starter clutch on the other end of the crank. You'll have to pull off the generator and will need an M16 x 1,5 bolt as a puller.

Sometimes the starter clutch screws back out and jam on the crankcase.

Alternatively, was the engine hot at all?
What color wre the plugs?

G


coolmg wrote:Engine seized while running. Took my CA77 for a test ride, and it ran fine for 26 miles, within a 1/2 mile of home running about 30mph the engine all of a sudden seized. With a wrench on the crank nut the engine will turn very hard. Removed the clutch so as to turn only the engine, very hard to turn. Removed plugs oiled the cylinders same problem. Drained oil and found nothing like metal in the oil, it was fresh oil and looked like it. Prior to the engine stopping I did not hear any tell tail sounds, it sounded great. Any suggestions would help please.
'60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160
'66 Matchless 350 '67 CL77
'67 S90 '77 CB400F

coolmg
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Joined: Fri May 27, 2016 1:01 pm

Engine seized

Post by coolmg » Thu May 09, 2019 2:31 pm

Engine was hot, I had just ridden it 26 miles. Plugs looked grey, were not white like it ran lean.

coolmg
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Joined: Fri May 27, 2016 1:01 pm

Post by coolmg » Thu May 16, 2019 1:44 pm

You were correct two bolts on the clutch were loose, and one was broken, engine is fine. My next question is when I reinstall clutch with a new kit what do I lubricate it with? Thanks again for advice.

jkv357
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Location: Middleton, WI

Post by jkv357 » Thu May 16, 2019 4:27 pm

Good call G-Man.

If not for a correct online diagnosis the engine may have been taken down unnecessarily or the cycle just parked indefinitely.

Pretty handy having so much knowledge available right here!

OldScrambler
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Post by OldScrambler » Tue May 21, 2019 6:44 pm

New Clutch.............clean everything..........soak plates and disks in new 30w..........use thread lock on the cap-bolts and let sit for 24-hrs before using.

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G-Man
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Post by G-Man » Wed May 22, 2019 2:48 am

Was that the starter clutch or the transmission clutch?

G
coolmg wrote:You were correct two bolts on the clutch were loose, and one was broken, engine is fine. My next question is when I reinstall clutch with a new kit what do I lubricate it with? Thanks again for advice.
'60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160
'66 Matchless 350 '67 CL77
'67 S90 '77 CB400F

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