Topic: 1974 cb550 intake manifold scratches...

[scaron]

hey gang,

i took a peek inside my intake manifold today and noticed these scratches... should i be concerned?

[bryanj]

Looks like something hard like a bolt has gone down there, if the cylinder is running i would hope any damage has been repaired already

[pjlogue]

Looks like someone tried to scrape off deposits at one time.  If there are raised ridges you can sand them down but it does not look like it is anything bad.  I would, as Bryaj suggested, check for any damage to the valve, cylinder in case it was a bolt that got ingested.

BTW/ some roughness in the intake path (i.e. not a smooth as glass finish) is good.  It promotes fuel air mixing for the intake charge.

-P.

[scaron]

@bryanj, yes the bike was running last year and can't think of any reason a bolt would have gone down it.

@pjlogue, as you suggest i think someone scratched it up but maybe not trying to remove deposits but rather trying to lever on a hard rubber intake piece? those things can be really difficult.

thanks for letting me know if the scratches won't cause the engine to run poorly.
 

[seanbarney41]

to me, it looks like someone did some very quick work with a carbide burr in a die grinder...maybe cleaned up some particularly nasty casting flash?...not really the right tool for the job done though.

I think it should run as good as an unmolested one.