Idle drops on sidestand part 2

[porndoguk]

MAKE THAT 3 MART, i was taught by the best

[oldgreyandslow]

[At last.. somebody else who can fit V4 carbs in a matter of minutes without using a sledgehammer!

And OGS.. I'm picking up the 30 on Saturday! Woop!

Post that vid then?

Update, I'm fairly sure its a carb's issue. I took it out again and it cuts out when warm, when started from cold, choke in after a short while idles happily upright at 1500, on the sidestand drops a bit.

Anyhow off for a short ride and everythings OK until I come to a junction and the engine is properly warm. Pull in the clutch, no throttle, it dies.

Starts OK, gets home, this time even upright starts OK then if I don't touch the throttle it dies. Tried upping the idle speed. OK when upright, back on the sidestand it dies. At this point the engine was properly warm, fan on, and it just won't idle.

So I guess its a carbs off job again. Mind you I don't really know what I'm looking for!

So all you clever "carbs on in 10 seconds" merchants, let us into the secret!

[arsey30]

Make sure fuel is flowing and there is no tap diphragm or vacuum hose problem.
Lay tank across bike with vacuum hose connected and fuel tap outlet over bottle and spin the engine over with the kill switch off.
Fuel should flow near full bore, not a trickle.

Loosen clips right off so little thread showing past the nut and position clip screws so that they are accesible.
Note, when tightening the screws, the clip will tend to turn round so that you cant reach the screw, and they are difficult to position back, so go gently with the screwdriver until the clip bites into the rubber.

Grease the carb stubs and rubbers, if warmed they are more supple, but I don't bother.
Engage the fronts first, pushing down until you hear them pop into the lip/groove, then perfectly align the rears, over the ports.
The carb won't sit directly over the rubber as the pitch in the V is wrong until the carbs are installed.
Because of this, the carb will try to fold in the back edge of the rubber, so slide a thin blade inside the rubber to bend out the rubber to allow the carbs to start.
You may need to prise the back of each rubber twice.
Push down on the rears until you hear them pop in , and check all 4 are fully seated.

If you try with washing up liquid first, they will go straight on, you can allways then remove them, clean off the liquid and apply grease, once that you have found how easy it is.

Dave.

[alexandervf]

Hi there,

If i get it right, until now, your problem might be your neutral switch, which is located somewhere on the left side of your engine (i do not know how i can give better description). I'm sure people here can give the exact words on this.

The exact symptom happened to me a few years ago (my bike is a nc35). You can run a simple test. Try, but be very careful, to lean the bike (while the engine is running, let it warm up first) as if it was on side stand, but of course do not use the side stand. See if it dies,
Then run the same test with the bike leaning on the side stand, if it dies when the bike is on side stand then you just solved the problem.

Alex

[oldgreyandslow]

Hi there,

If i get it right, until now, your problem might be your neutral switch, which is located somewhere on the left side of your engine (i do not know how i can give better description). I'm sure people here can give the exact words on this.

The exact symptom happened to me a few years ago (my bike is a nc35). You can run a simple test. Try, but be very careful, to lean the bike (while the engine is running, let it warm up first) as if it was on side stand, but of course do not use the side stand. See if it dies,
Then run the same test with the bike leaning on the side stand, if it dies when the bike is on side stand then you just solved the problem.

Alex

Not quite sure how the neutral switch makes it die when I came to a halt with the bike in first, clutch in and then it died still in gear, but I'll check anyway. And the rev's falling when on the side stand?
Still I'll try anything and everything!

Make sure fuel is flowing and there is no tap diphragm or vacuum hose problem.
Lay tank across bike with vacuum hose connected and fuel tap outlet over bottle and spin the engine over with the kill switch off.
Fuel should flow near full bore, not a trickle.

Loosen clips right off so little thread showing past the nut and position clip screws so that they are accesible.
Note, when tightening the screws, the clip will tend to turn round so that you cant reach the screw, and they are difficult to position back, so go gently with the screwdriver until the clip bites into the rubber.

Grease the carb stubs and rubbers, if warmed they are more supple, but I don't bother.
Engage the fronts first, pushing down until you hear them pop into the lip/groove, then perfectly align the rears, over the ports.
The carb won't sit directly over the rubber as the pitch in the V is wrong until the carbs are installed.
Because of this, the carb will try to fold in the back edge of the rubber, so slide a thin blade inside the rubber to bend out the rubber to allow the carbs to start.
You may need to prise the back of each rubber twice.
Push down on the rears until you hear them pop in , and check all 4 are fully seated.

If you try with washing up liquid first, they will go straight on, you can allways then remove them, clean off the liquid and apply grease, once that you have found how easy it is.

Dave.

Dave

Its a new vacuum hose. I'll check the fuel flow. I used a screwdriver as a lever on the rears when I refitted the carbs, what I didn't do though was fully fit the fronts, perhaps I'll use a couple of old dinner knives instead?

I guess its carb's out, check floats etc and then try this method I have a huge tub of red rubber grease so I'll apply that to both carbs abd rubbers

Thanks all.

[arsey30]

A faulty or disconnected neutral switch will stop the engine running or starting.

A thin narrow blade is best, but if the rubbers are flicked out when they try to turn back in, then that's OK.
Push down on the back carbs in turn, engaging 1 at a time.

As I said , washing up liquid is the best lubricant for carb rubbers and any other rubber parts like fitting wiring grommets or fairing lugs into their housing and lugs into them.

Dave.

[oldgreyandslow]

A faulty or disconnected neutral switch will stop the engine running or starting.

A thin narrow blade is best, but if the rubbers are flicked out when they try to turn back in, then that's OK.
Push down on the back carbs in turn, engaging 1 at a time.

As I said , washing up liquid is the best lubricant for carb rubbers and any other rubber parts like fitting wiring grommets or fairing lugs into their housing and lugs into them.

Dave.

OK mate. thanks, I'll find something thin and narrow and washing up liquid it is. Probably be next week before I have a go again, watch this space.

[oldgreyandslow]

Fuel flows out of the tap OK, however I did notice a bit of petrol on the outside of the pipe leaving the tank when I lifted it, also the securing clip seemed a bit loose.

Before checking the tap I thought I'd start it again, started OK on choke ran at about 4k when I put the choke back it wouldn't idle at all well, actually stuck around 2000 rpm for a while, when I opened the throttle a bit it was reluctant to fall back.

Took all the plastics off and tried again after checking the tap, its still dropping on the side stand and still not idling right, so its off with the carbs again, check floats etc again! and try the refitting technique advised by Dave (arsey 30) above. However not till next week as I'm cycling the Wight Sportive tomorrow.

[arsey30]

It sounds like you still have the original fault, fuel related , either air leak or weak mixture.

Does the fuel flow near full bore out of the tap.
Try fitting a funnel or bottle to the feed pipe so that you can pour petrol direct intp the carbs, I suspect tap diaphragm.
If you remove carbs, check pilot screw settings and pilot jets and airways.

Dave.

[oldgreyandslow]

It sounds like you still have the original fault, fuel related , either air leak or weak mixture.

Does the fuel flow near full bore out of the tap.
Try fitting a funnel or bottle to the feed pipe so that you can pour petrol direct intp the carbs, I suspect tap diaphragm.
If you remove carbs, check pilot screw settings and pilot jets and airways.

Dave.

Yes the fuel comes out full bore, a constant steady stream

I am going to take the carbs off Monday and clean and check yet again.

Pilot jets are new, purchased from Rick Oliver last month, pilot screws are set 2 turns out

I'm pretty sure its been running rich not lean

I'll check and clean everything again or look at getting a recon'd set of carbs