Engine seize after complete engine rebuild

[RBoss]

Hi all,

So I have rebuilt my engine completely to replace the primary chain. Put the freshly painted engine in a freshly powdercoated frame, but after riding two trips of a total of 100km, my engine seized on the motorway. After getting to a stand still the electric start could not turn over the engine anymore and the kickstart was seized up as well. I feared for the worst.

However after being towed to the first gas station the kickstarter was free again and I could start the engine with the electric starter. The engine didn't sound as nice and quiet as right after the rebuild though. I am quite lost what the problem could be...

I'm thinking of the engine running too hot and seizing up the pistons, especially as it freed up again. I am also afraid that this is because I might have used too much liquid gasket when putting the two engine cases together.

Some context info: I have ridden the bike two times after the rebuild and before the breakdown. 1st time was on the motorway at a normal pace, second time was on countryroads quite easily. The breakdown ride was a little faster at around 130km/h for 15 min on the motorway before it seized. I started on the motorway almost straight after starting up the bike.

Anybody that has some advice or might know what this would be, as well as how to solve it, or diagnose the bike? All the help is welcome!

attached some pictures of the engines liquid gasket, and my breakdown...
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[K2-K6]

Ooooh that doesn't sound good

The gasket cement I would guess could be the prime suspect here. If any oil supply routes have been compromised by excess squeezing into them, then that can easily lead to problems.

Not easy to assess without looking inside,  at least the cam cover to start with.

[K2-K6]

To add, I'd not run it like it is until understanding quite what is happening inside.

[Oddjob]

What exactly was done on the rebuild?

Did it have a rebore for example?

First thing I'd do is pop the camcover off, I suspect the cam may have seized, it freed off when the engine cooled as the metal would contract when colder allowing it to start to spin again, however it's probably toasted the head and most likely the cam. You may get away with the rockers as the mileage was still low.

Did the oil light come on before it seized up?

[RBoss]

What exactly was done on the rebuild?

Did it have a rebore for example?

First thing I'd do is pop the camcover off, I suspect the cam may have seized, it freed off when the engine cooled as the metal would contract when colder allowing it to start to spin again, however it's probably toasted the head and most likely the cam. You may get away with the rockers as the mileage was still low.

The oil light didn’t show so I guess oil pressure was OK.

Did the oil light come on before it seized up?

I replaced the primary and cam chain, and lapped the valves and replaced the valve seals. I didn’t do anything else to the head and cilinder as the pistons + rings and cilinder bores looked good.

I’ll start pulling the top off soon to start diagnosing.

[Charliecharlcomb]

Let us know what you find. Any oilway that has become blocked will cause terrible damage if not cleared. Good luck!

[K2-K6]

Worth pulling the oil filter to inspect it and see what's in there.

Also the gauze filter on the oil pump sump pickup, inspect and assess to see if it's impaired.

[McCabe-Thiele (Ted)]

That looks as though you have a gasket between the Crank case halves not an ultra thin layer of Hondabond?

[Sesman]

Any news on the cause?

[Oddjob]

Worth pulling the oil filter to inspect it and see what's in there.

Also the gauze filter on the oil pump sump pickup, inspect and assess to see if it's impaired.

Second that, when my oil filter collapsed on the motorway (pattern filter BTW) the oil screen was almost completely covered in fibres, I'd imagine yours will be full of gasket cement, it should be really thin, that's FAR too much.

[McCabe-Thiele (Ted)]

As a serial worrier I would be concerned that the excess crank case sealant might lead to an issue with the main bearing clamping causing excess clearance or loss of oil flow elsewhere. As has been said more likely the sealant has entered the oil galleries.
I hope its not caused damage to the internals - removal of sump & oil filter should help you decide the best way forewards as has been already said.

[Laverdaroo]

It's probably the angle of dangle of the photograph or the fact that you might have moved the internals during getting the cases apart, (especially with all the silicon on there). BUT, I was having a quick look and the Primary chain is well 'on the wonk' and looks to be running at an angle. Is it the former and the latter or are my eyes getting worse?

[Deano400]

It's because there's no primary shaft holding the primary drive in place. Primary shaft is in the lower case when assembled.

[Laverdaroo]

I thankyou.
Thought that might be something to do with it but you gotta ask haven't yer?
See, I told you I knew nowt