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Honda CB516 Cafe
Mace53:
Hey guys
After over 20 years sat rusting and feeling sorry for herself, I have finally got the old girl started! Very chuffed.
She runs really well, and sounds great with the 4 to 4 drag exhaust I made up.
Carbs are all synced and work great together.
She fires up straight off the kick even on a cold start.
However, I didn't think that my first engine rebuild would go smoothly and I do have a problem which im struggling to figure out.
The #1 cylinder is smoking quite a bit but only one the bike is fully warmed up. Nothing on cold idle or light revving from cold. Its a combination of blue and grey smoke and is definitely an issue.
Compression tests across all 4 cylinders :
1- 150
2- 155
3 - 150
4 - 158
After 5 mins of idle and revving these pictures are what I discovered:
Still image from a video I took.
End of the exhaust.
Exhaust valve.
Wet oil from the exhaust hole.
But the spark plug looks ok?
I've been reading reading checking and struggling to figure out what the primary cause may be.
I'm running the carbs lean on 3 turns out due to the pods and 4-4 exhaust.
The previous topics on here point to leaking oil around the piston rings and leaking oil from the valve stem seals. But both are brand new.
I'm running an electronic ignition with brand new dr8es ngk plugs and ngk caps and leads.
Any ideas at all?
Sent from my E2303 using Tapatalk
Bryanj:
Bad stem seal or cravked guide in my opinion
Mace53:
Cracked guide as in the guide it physically sits in?
Sent from my E2303 using Tapatalk
Bryanj:
Yup, if some one in the past has not been carefull when fitting the valve cover you can crack the guide below the seal
Tomb:
And if cracked guide or bad stem seal on exhaust valve your plug will look ok as you don't suck oil in the cylinder.
Check the actual valve stem where it sits in the guide within the exhaust port.
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