Honda-SOHC

Hi, would welcome some further advice, please.

I had a minor blow from the head gasket, which became a small drip whenever I stopped and popped it on the side-stand. I investigated the nuts visible next to the spark plugs. One of them (next to cyl  no.3) was so loose I could turn it with my fingers. Cyls 2 and 4 were also not very tight. When the previous owner bought my bike, he found a handwritten note stating the piston rings had been replaced. The bike has done 650 miles since then. I'm guessing it has settled and requires a re-torque. That's my experience with old British twins, don't know if that happens on the CB750?

I've tightened them up and I think it is much improved. I would also like to check the rest. Is it possible to check and tighten the remaining head nuts, without removing the engine?

Thanks,

Martin

I've hopefully got the carbs where they need to be, for the moment!

Rather than add to that topic, I thought a new one is in order!

I have some miscellaneous other minor issues to have a crack at and any words of wisom are very welcome:
- Neutral switch needs checking, remains dimly lit when in gear;
- I have a strange tramping sensation through the bars on some roads at speeds over 30mph. I'm hoping it is wheel balancing, as the red dot is not right on the tyre valve, and there is a 20g wheel weight close to the valve, which isn't where I'd expect it? However it may be front suspension. Standing, front brake on and pumping the bars, it moves up and down and seems damped, but is stiff. Will check which fork oil it has in there. What grade is recommended for a compliant ride?
- Difficult to find neutral, easy when rolling to a stop, but not when stationary;
- May be related; the clutch bite seems quite late in the lever outwards movement, but no clutch slip is evident when i open the throttle. Is this usual?

👍

Hi,

My neutral switch is bright when the bike's in neutral, dim in 1st and 2nd and extinguishes further up the 'box. I've searched on here and checked the wiring under the engine, which looks ok. I thought I would remove the switch and clean it, but with the locating screw undone, it will not budge. Is there a knack to getting it out?

Thanks, Martin

Hi,

As mentioned in a previous topic, Im looking into why my new 750K6 is reluctant to tickover and run, particularly no.4, along with a stiff throttle that won't return on its owm. The ignition / timing looks ok. Plugs will be replaced.

I've removed and cleaned the carbs and fuel lines. I found 2 things;
-Floats were set at around 30mm above the bowl rim. So maybe it was lean? I've put it to 26mm and will watch out for leaks!
- I was unable to see through two of the slow jets (one was no.4). Hopefully, now all clean.
I'm not familiar with Keihin, nor multi carbs set ups. Im used to single Amals!  At this stage, I only cleaned what I could get to from the float bowl without dismantling them from the gantry system. I'll replace the fuel, the tank is very clean.

I'll crack on this morning. A couple of questions:

I know the carbs were not synch'd prior to taking them off. Is there a good method to getting a base setting on all 4, before re-installing? I have vacuum guages for once it's running (that will no doubt, be fun and games!).

The issue with the throttle not springing back remains a mystery. Cable run is smooth arcs. They were a little, very slightly, stiff.  I don’t think this was the issue. I've flushed them through with silicon lube. They are now nice and light. Off the bike, the throttle movement on the carbs gantry is very stiff. Im not able to shift it manually. On the bike, once the cables were removed, they did operate and spring back. The springs look ok. Should I be lubricating something, or easing any clearances? Is there perhaps a 'usual cause' for this?

Thanks, Martin

Hi,

I introduced myself a couple of weeks ago, when i was looking for a CB750. Well, I've just collected my new (to me) K6. I'm working through a gremlin it has:
- Won't run if it's off choke, after warming for a few minutes, by which time it'snot happy running on choke;
- No.4 is not getting as hot; and
- No throttle play / not returning back on the twistgrip).

I'll go through the carbs. Check, clean, synch etc. Manifold rubbers look OK and clean new airfilter, airbox looks OK. Before I do, I'm going to check the ignition over (points), plugs, coils and leads, plus timing. I'd also like to clean and check the contacts on the kill switch. I'll also look at the valve clearances (and cam chain tension while I'm at it).

Would be grateful for some advice:
- The throttle cables are the stock push/pull arrangement and look to be in good condition.  The spring is there on the gantry. Is there anything obvious I should look into? Cable adjustment be a cause?
- How do I get under the kill Switch, does it pop off from the outside, or do I need to remove the control from the handlebars, to get in from behind? Couldn't find this in the Service Manual.
- Any other suggestions on where to investigate? Afraid I don't have the kit to do a compression test.

Thanks, Martin