Idling @ 8000 rpm

[cbfb]

When we spoke on the phone I could hear the butterflies slamming home when you shut the throttle I thought. Would be funny if that was infact a linkage hitting a hose clamp.

Aye that's right you did, I remember now. Althought by then I had taken the airbox off so still can't rule out that something was catching (although less likely to be something from there).

[jonbuoy]

Wasn't gonna call you on this, but I will cos your attitude bugs me.

Run a bike with CV carbs without a filter and it will idle fine, but run like a sack of shit when you are on the throttle. Because there is a delicate balance of spring tension versus air flow to be maintained in order for the slides to sit at correct levels for the engine speed.



When we spoke on the phone I could hear the butterflies slamming home when you shut the throttle I thought. Would be funny if that was infact a linkage hitting a hose clamp.

Wow I feel so shamed - I couldn´t care less if my attitude bugs you, I´m amazed you can tell what my attitude is through the interweb. My point was to try and help the guy identify if one or more carbs was causing the issue and maybe let him run the engine for more than a couple of seconds to ID the vacuum leak if there was any. There wasn´t much in occurring in the thread. I didn´t suggest he run full time without filters - No attempt at a good deed goes unpunished on KB.

[cbfb]

OK well I checked the carbs tonight (by that I mean the top; diaphragm, slides, butterflies etc). All looking good.

Next I reassembled everything. Put fuel tap on 'prime' and turned it over a couple of times, nothing. Switched to 'on', started with a bit of help from the throttle. Adjusted idle screw to rev around 2000rpm (although a little erratic). Holy shit, fuel pissing out of overflow hoses and smoke coming from front of engine (near rocker cover). Appears to be some coolant around, but could be a red herring - recently refilled radiator. Rad is still full. Oil level seems OK. Suspect fuel overflow due to me turning it over on 'Prime'? Cause of smoke unknown, thought maybe fuel burning off?

Let engine dry and used compressed air to blast away as much gunk as possible (concerned about residue from CRC, oil etc smoking)?

Started up again. Carbs not leaking but smoke definitely coming from centre of rocker cover (front), smell is like burning rubber. Wonder if it's possibly the rubber grease I used on the rocker cover seal?

Checked oil level - oil may have gone down marginally, possible oil leak around rocker cover gasket? If this was true would expect oil residue but it looks fairly clean. Would leaking oil smoke like that? Would oil smoke smell like burning rubber?

Rad has gone down slightly, but maybe expected seeing as though bike has only run for a few minutes since refilling coolant?

I degreased the engine, carbs, rad, exhaust and have left it out in the shed to dry off overnight.

So worse case scenario, losing oil and coolant but where's it going? Head gasket could be an explanation but I've just replaced the head gasket. Hmmm.

Anyway the only idea I can come up with is fill the oil and coolant up tomorrow then let it idle for a couple of minutes, just long enough to heat up. If the smoke is just crap burning off, hopefully it will stop. And if there is an oil/coolant leak somewhere hopefully it will give me some clues.

And as for the carbs, I am hoping that is all OK now... fingers crossed...

Any ideas/suggestions more welcome than ever!

p.s. sorry for being a bit of a hopeless mechanic so far, it's a steep learning curve unfortunately i've got more enthusiasm than ability at the moment...

[Katman]

Checked oil level - oil may have gone down marginally, possible oil leak around rocker cover gasket? If this was true would expect oil residue but it looks fairly clean. Would leaking oil smoke like that? Would oil smoke smell like burning rubber?

It takes a while for all the oil to drain back into the sump - particularly when it's still relatively cold. If the level is only down slightly then there is nothing to worry about.

[cbfb]

It takes a while for all the oil to drain back into the sump - particularly when it's still relatively cold. If the level is only down slightly then there is nothing to worry about.

True, however I just went back out to the shed and it hasn't gone up again yet.

Worse still, I noticed that there is a slight greeny colour to the oil. Drained some off, the oil is black but yeah it definitely has a green tint. I'm assuming coolant has got in there?

May not be so bad as I haven't changed the oil since refitting the head & block so maybe some coolant got in there then... was gonna change the oil after I'd got it running. Will do it immediately.

[Katman]

True, however I just went back out to the shed and it hasn't gone up again yet.

Worse still, I noticed that there is a slight greeny colour to the oil. Drained some off, the oil is black but yeah it definitely has a green tint. I'm assuming coolant has got in there?

May not be so bad as I haven't changed the oil since refitting the head & block so maybe some coolant got in there then... was gonna change the oil after I'd got it running. Will do it immediately.

If you fitted a new oil filter when you reassembled the engine that may well explain the drop in the oil level. The oil capacity cast into the engine casing is usually the amount needed without the oil filter being changed. You need to add some oil once the oil has been pumped into the filter.

[cbfb]

If you fitted a new oil filter when you reassembled the engine that may well explain the drop in the oil level. The oil capacity cast into the engine casing is usually the amount needed without the oil filter being changed. You need to add some oil once the oil has been pumped into the filter.

Nope I left the old filter in there, was being a cheapskate. Only had the motor apart because I had stripped one of the cam journal bolts and needed to take the head off to sort that out.

I'm getting a bit concerned that the oil is getting pumped up into the rocker cover and there's some sort of obstruction preventing it from getting back down to the crankcase? That would suck.

[FJRider]

I'm assuming coolant has got in there?

If water gets into the oil ... it goes white ...

[cbfb]

If water gets into the oil ... it goes white ...

Aye, I agree with that. Just thought coolant is green therefore oil + coolant = green.

Have read on t'interweb though that some bike oils are green??? News to me but maybe that's what it is.

Won't hurt to do an oil and filter change tho, was gonna do it anyway.

[FJRider]

Aye, I agree with that. Just thought coolant is green therefore oil + coolant = green.

Have read on t'interweb though that some bike oils are green??? News to me but maybe that's what it is.

Won't hurt to do an oil and filter change tho, was gonna do it anyway.

Finish what you started already ...

[cbfb]

Finish what you started already ...

Sorry don't understand?

[FJRider]

Sorry don't understand?

AFTER you know it's running smoothly, with no issues. (NO leaks of anything)

A short run if it seems ok ... with a clean engine to start with. Leaks then become obvious.

[FJRider]

Nope I left the old filter in there, was being a cheapskate. Only had the motor apart because I had stripped one of the cam journal bolts and needed to take the head off to sort that out.

I'm getting a bit concerned that the oil is getting pumped up into the rocker cover and there's some sort of obstruction preventing it from getting back down to the crankcase? That would suck.

The oil channels to the crankcase are not that big ... and it is usual to expect a drop in oil level if checked cold then run for a bit. The oil has spread itself around the engine ... as it is supposed to. It will drain down again ...

[Drew]

Don't over think stuff too much. The smoke is probably residue burning off, but a leaky rocker cover gasket is easy to fix.

I'm with FJrider, get it running and go for a short buzz down the road.

[cbfb]

AFTER you know it's running smoothly, with no issues. (NO leaks of anything)

A short run if it seems ok ... with a clean engine to start with. Leaks then become obvious.

Good point, yep will do that.

The oil channels to the crankcase are not that big ... and it is usual to expect a drop in oil level if checked cold then run for a bit. The oil has spread itself around the engine ... as it is supposed to. It will drain down again ...

You're right, they're not very big, that's why I was concerned about them getting blocked up. But yep it makes sense about the oil getting spread around, would be a bit buggered if it didn't!

Don't over think stuff too much. The smoke is probably residue burning off, but a leaky rocker cover gasket is easy to fix.

I'm with FJrider, get it running and go for a short buzz down the road.

I can't help it, that's my job!

OK I'll give it another crack tonight.