What fuel are you using and couple of questions

Hi again. Glad to find this place again. I don't know if it's the same forum as before but I had to re-register.


I wonder if anyone can help?

What fuel type are you using. This is the first time I've been on the forum since E10 came out.
I've got intermittent knocking sound (sounds horrendous) when the morning start goes below about 5 degrees C.
The bike is very fussy exactly where the choke is, and then starts ok, but then after about 20 seconds and for a few minutes, produces a knocking sound,
and can, if that choke isn't exactly right, stall.


Also while I'm asking questions, I'm off on a 90 miles ride at the weekend, and would like to know something that has always given me anxiety.
The coolant is checked at the reservoir down below according to the Haynes manual right? How does this work? Why does the coolant not run straight down and spill out the reservoir by gravity? Sorry if I'm being an idiot?  It's just that I was stuck in traffic and I noticed the temp going up a b it higher than usual.

I've owned the bike over 20 years, but as you get older, you can start to question what you were previously ignorant to and clearly confident in your ignorance! lol

Hi,

On the question of fuel I use a mixture. If I can get it, E5, but usually E10 as I live in the sticks. I've had no issues with fuel causing either performance or other issues, other than the time I mistook diesel for petrol.

I don't notice any real difference with E10, though I'm pretty sure the supermarket petrol gives me worse mileage than my local garage  (both E10). 

My CB's choke is also a bit like you describe, and if I turn it off within the first 30 seconds or so it will stall, but there is no knocking sound, just sweet purrs and burbles. I have a VFR750 that had a horrible knocking sound when warming up though. Once it was warm the sound went away. It turned out to be a worn clutch basket and once I replaced it (I replaced the whole system, from lever to plates) it went away. Does the knocking go away if you pull the clutch lever in? If so it might be the basket. I'd try to locate exactly where the sound is coming from.

I don't really know about the coolant question, someone more knowlegable than me can answer it, but the reservoir should lead to some kind of pump that distributes coolant around the engine. When it gets hot enough a thermostat/gate opens that lets it into the radiatior to cool down and judging by my VFR, when it gets too hot there's an overflow that dumps it out a little pipe at the bottom making lots of steam and scaring the beejezus out of me. So it should be pumped around the engine from the reservoir, not just fed by gravity. This is all guessing though, I'm no expert. You might want to check if your fan is running if the temps are climbing, that was the issue with the VFR's steamy outbursts.

how many Km has the bike ?
maybe you are looking at a wrong direction, fuel quality, and it's just the cam chain tensioner.

the hose from the filling cap to the expansion tank is a two way hose, sends the hot fluid to the expansion tank when hot and siphons it back when cools down

Balth, no, the sound doesn't go away when you pull the clutch leaver, it stays exactly the same. I even tried rocking the bike side to side to slosh oil around. I expect the neighbours think I'm mad!!!

Panag, the bike has done 30,000 miles from new. Don't know what that is in km? The only work I've had done on it apart from one crash, is I had the manufacturer recommended clearances done at 16,000.

Superfly, what about spark plugs, air filter ? do you do common regular maintenance stuff ?

I'm running my bike on E10 and have had no issues. I'm at 110.000 km or thereabouts, and have replaced most of the model-specific weak-points; cam chain tensioner, regrec - and have made sure that the front engine bolt isn't seized in its seatings. Bike's got the obligatory clutch basket rattle on startup and that would have been my first guess at "noises on cold start". But it isn't that, as someone else beat me to the question/answer.

CCT?

The level of the expansion tank is designed to leave space for water (and air) to come down from the circuit and arrive below it so that everything that rises later when it cools is only liquid.

stormbringer, have you changed clutch discs ?

have you open it ?
I did the clutch discs at your Km (and the CCT later) , the basket looked Ok that time.
now at 181KKm the clutch is OK, no slipping, but the clutch basket noise is there at cold start ups.
pooling the lever, disappears , getting hot, the same.
In short: what causes this noise ?

The cold starts are just about over for this year in the UK. I went out to take a video of it and it wouldn't do it. DOH!

The bike coped well with the ride 80 miles one way and on the way back the whole of the A34 was closed and I did 120 miles down the lanes to get home. There was traffic and the temp gauge did go up, and the fan came on a couple of times and it stabilised and when got going again, it came back to normal. Still, I would really love to know why when you pull that rubber cover off the expansion tank it doesn't well up and spill all over the floor!

the expansion tank is not under pressure, that's why.
the expansion tank is open to the atmosphere through a small hose on it's top.
if you fill it up completely, you'll see fluid coming/dropping from this hose.
the expansion tank receives/resends the fluid from the hose coming by the rad cap to it's bottom.
this cap is a vital element, has a valve's action.
when the engine is HOT, excess fluid, due expansion, through this hose enters the expansion tank.
when the engine gets cold, fluid shrinks and sucks/siphon back fluid from the expansion tank to the engine.

Once we are sure that we have eliminated all the air from the circuit, then only fill it to the minimum marked to prevent it from spilling when it heats up due to overfilling.

Hi...what I do with my CB500S,1999,is using an infra red temperature gun with a laser dot.Use this all over the engine and radiator,pipes ectera, do this after each ride,record results to see how temperature changes .My bike runs best on E5 fuel.