CB650 Swedish Cafe

Snejkaj

Active Member
This is my first motorcycle. So why not enter with style :)
Got it from my father in a semi poor condition. Blue smoke and rubber brakes.
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First step was to put on some new valve seals and steel braided brake lines. I got my learner permit and got a few hours in the sadle.
My plan is to make it cafe:ish during winter. Poor valve seals has left thick black layer in the cylinder head. So I pulled it off snd threw it in a washing mashine at work and then a couple of hours in the ultrasonic cleaner.
This is after washing. Ultrasonic cleaning will be finnished today.

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Made some adjustments to the front fender
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All electrics will be new.
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Engine will get lapped valves and new piston rings. For the gearbox I've got som NOS gears so it will not pop out of 5th
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Then there will be som new clipons and switches.
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The ultrasonic almost did the job. Need some manual work also. Next step is to resurface it in the mill.
 
Lapping new valves is unneccessary if you are going have the seats machined. This is an antiquated process that reduces the life of the valve and the seat.

You might find that front fender to be a bit short to keep rain and stuff from coming up, but thats a minor issue imo, and I like short fenders.

You need to inspect and measure your shift forks and drum, not just the gears. Popping out of gear is usually due to worn forks, not worn gears.

Welcome to DTT, lots of cb650 projects popping up!
 
Think I'll order a drum and forks. Nice to have som NOS-parts just in case :)

Tank is primed an ready for filler.
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DohcBikes said:
Lapping new valves is unneccessary if you are going have the seats machined. This is an antiquated process that reduces the life of the valve and the seat.

You might find that front fender to be a bit short to keep rain and stuff from coming up, but thats a minor issue imo, and I like short fenders.

You need to inspect and measure your shift forks and drum, not just the gears. Popping out of gear is usually due to worn forks, not worn gears.

Welcome to DTT, lots of cb650 projects popping up!
If the guides are good and seats+valves are fresh there is really no need to machine them is there?
 
datadavid said:
If the guides are good and seats+valves are fresh there is really no need to machine them is there?
One of the best ways to gain power is through a 5 angle valve job. He seems to have access to some nice machines, so I did jump to the conclusion that he will have his seats cut.

In any event, the only time it is practical to lap valves is if the valves are new, and the seats are not. And so when we take that into consideration, we should realize that what we are doing at that point, is asking a new valve to make nice with an old seat, and we are effectively shortening the life of the new valve AND sometimes the seat.

Personally, I dont really see the point to putting new valves in an engine unless they are really bad, and in that case the seats likely are wide and cupped just like the valves are. When you slam a new valve in there and immediately grind it to match the old seat, well, you tell me what happens.

Now granted, if thats the combo, then at least light lapping is almost a must, but it will never seal as well as new valve, fresh cut seat.

With a new valve, a new guide and a fresh 3 or 5 angle, done on a SERDI with air float centering, lapping the valves has been proven to increase wear and decrease power.

I'm not sure whether he has new valves with old seats, old valves and old seats, or new valves with new seats. I'm interested to hear more.
 
DohcBikes said:
One of the best ways to gain power is through a 5 angle valve job. He seems to have access to some nice machines, so I did jump to the conclusion that he will have his seats cut.

In any event, the only time it is practical to lap valves is if the valves are new, and the seats are not. And so when we take that into consideration, we should realize that what we are doing at that point, is asking a new valve to make nice with an old seat, and we are effectively shortening the life of the new valve AND sometimes the seat.

Personally, I dont really see the point to putting new valves in an engine unless they are really bad, and in that case the seats likely are wide and cupped just like the valves are. When you slam a new valve in there and immediately grind it to match the old seat, well, you tell me what happens.

Now granted, if thats the combo, then at least light lapping is almost a must, but it will never seal as well as new valve, fresh cut seat.

With a new valve, a new guide and a fresh 3 or 5 angle, done on a SERDI with air float centering, lapping the valves has been proven to increase wear and decrease power.

I'm not sure whether he has new valves with old seats, old valves and old seats, or new valves with new seats. I'm interested to hear more.
Yea, well, lapping the valves IS wear so.. but yes, of he can do it why not? Everything looks fresh in pics but who knows?
 
Unfortunately I don't have access to a machine to do a valve job :/ New valves are a job for next winter. My budget is a bit limited right now. :/
 
I got some black paint to se if the tank was smooth... It was darkgrey metallic. Looks nice so I'll keep it that way :)

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