Topic: Kent restores a '70 CB750KO

[kbart1]

hey guys

2 questions:

I recently rebuilt my petcock however it is still dripping a little fuel even when it is off. does the little wafer with the holes in it need to go in in a certain way? obviously one hole goes over the nub in the petcock to secure it but is there a front or back to the wafer? it looks the same on either side.

I also am trying to figure out the routing for the 2 hoses from the carbs that goes up to the petcock? anybody have a photo perhaps or can explain the routing?

thx a lot!
kent

[754]

Sometimes I used a bit of grease on the rubber in the petcock. Helps seal a bit till the gas will likely puff up the rubber bits..

[Greggo]

I used some grease and mine still leaks a bit.  I'm going to go back in and bend the washer behind the knob just a bit more.

[Johnie]

Here you go Kent. The pic is of the fuel lines between carbs 3 & 4.

[kbart1]

hey all

so i have rolled this cb750 out of the back of the garage after awhile of not playing with it. i am gonna have a couple more questions as i am starting to tinker with it again. here ya go:

there has always been a bit of a rattle at idle and i was thinking it was cam chain related. i adjusted the tensioner as per the manual at 15 deg off tdc for # 1 cyl. and it seems to have gotten a BIT quieter. i decided to pull the tensioner out of the bike which i didn't realize was so easy. the tensioner is working as it should and it is not near the end of its extension. i did however jam my finger in the opening to feel the part that it pushes on when installed to tension the chain. i tried to move that part to see if it was free'd up and i cant move it. if it is designed to move in relation to the cam chain tensioner should it not have some movement to it? FYI when i rev the bike up a bit the rattle seems to go away...........

i adjusted the valve lash however the cam cover is on so i had to use the tappet cover holes. my blade style feeler gauges do not fit in there very well so i am concerned how accurate they are. is there a different set of feeler gauges that would work better for this?

when replacing the tappet cover plugs i cracked one. stupidly over torqued it!  anybody know where a guy can buy just 1 tappet plug?

checked timing as well using my strobe. 1-4 were dead on accurate. 2-3 i need to work on a bit to get them spot on. stand by.

thats it for now. interested in any and all feedback. thanks!

[Stev-o]

hey all

so i have rolled this cb750 out of the back of the garage after awhile of not playing with it.

5+ years?!

As far as the rattle noise at idle, have you sync'd your carbs?

[MauiK3]

Get thinner ended feeler gauges
Do all tuneup work prior to adjusting the carbs.
Cam chain tensioner adjustment only works when the engine is in the correct position.
Look on ebay for your valve cap. As you now know, they are fragile and only require light snug up, the o ring is what seals.

[HondaMan]

Does the noise go away at, say, 1500 RPM?
(This is a loaded question...)

[Don R]

 clutch rattle?

[Don R]

 I believe the white corrosion was caused by gas additives from certain years fuel.