Topic: 550 Shakedown clutch "grab"?

[exponent]

Hey all,
Took my freshly rebuilt 78 550 engine out for a real shakedown ride today. Toward the end I experienced a slightly scary grabbing feel of the clutch or final drive. Bike was in gear and cruising when it irks and front suspension compresses, loss of power etc. When I pull the clutch in I still coast and nothing is impeding. Cannot tell if this is exactly the clutch or carbs but it felt as though something was grabbing, not like a loss of fuel or spark. Would a clutch adjustment remedy this? I could not find proper adjustment instructions for the nut on the outside of the clutch cover when assembling, this was my first guess, second guess is that there was something in the plates or in the trans locking things up spontaneously.
Any info helps, note this was at the end of about an hour of riding. Maybe it will go away on its own like magic? If you've experienced this please tell

[bryanj]

Adjustment spec is in the Honda workshop manual, there is a mark on the case and a notch on the lever that you use the screw inside the nut to line up then lock up the nut,

WARNING. Do not turn the screw all the way as you will make the operatng arm jump the cam inside the case requiring case removal

[ekpent]

The symptoms don't really sound like a clutch problem but does "irks" mean jerks ?  You mentioned loss of power ?

[calj737]

First thing I’d check is the drive chain. I would carefully inspect the swingarm pivot bolts and rear axle adjusters to ensure they are torqued and chain slack is correct. I have never seen a clutch “grab” while riding especially under the conditions you describe.

[Nurse Julie]

Are you sure the engine isn't about to seize 🤔🤔🤔

[ekpent]

Are you sure the engine isn't about to seize 🤔🤔🤔

I kind of thought that also with the forks compressing and maybe the engine acting as a brake combined with loss of power.

[exponent]

Are you sure the engine isn't about to seize 🤔🤔🤔

I kind of thought that also with the forks compressing and maybe the engine acting as a brake combined with loss of power.

No idea why it would seize, has been fully rebuilt with new rings and seals

[Nurse Julie]

Are you sure the engine isn't about to seize 🤔🤔🤔

I kind of thought that also with the forks compressing and maybe the engine acting as a brake combined with loss of power.

No idea why it would seize, has been fully rebuilt with new rings and seals

Any newly rebuilt engine is a likely candidate for a seize for many different reasons. I certainly wouldn't rule it out going by your description of the symptoms.

[exponent]

What are the common failures?

[Nurse Julie]

What are the common failures?

The main one would have to be oil starvation to top end and the crank due to oil starvation, usually due to debris in the oilways and oil gallery going up and blocking the oil restrictor jets.
Then there is running in the engine incorrectly, by loading the engine too much.
There is also a high risk of seizure by leaving the engine running whilst syncing the carbs etc, with no air flow around the fins, the engine gets far to hot and seizes. This can also happen if you are riding the bike and not letting the engine go through complete heat cycles, ie hot, cool, hot, cool. This usually happens if you keep stopping regularly.
Incorrect piston / bore clearance, far too tight.
They are the most common reasons.
Then there can be errors made during rebuild, wrong parts/ wrong places / incorrect tolerances / component failure during or post build.
Poor cleanliness during rebuild.

[exponent]

What are the common failures?

The main one would have to be oil starvation to top end and the crank due to oil starvation, usually due to debris in the oilways and oil gallery going up and blocking the oil restrictor jets.
Then there is running in the engine incorrectly, by loading the engine too much.
There is also a high risk of seizure by leaving the engine running whilst syncing the carbs etc, with no air flow around the fins, the engine gets far to hot and seizes.
Incorrect piston / bore clearance, far too tight.
They are the most common reasons.
Then there can be errors made during rebuild, wrong parts/ wrong places / incorrect tolerances.
Poor cleanliness during rebuild.

Ok thank you I will consider these