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Julian Tomkins

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took the bike out yesterday enjoying how it rode and pleased with my freshly clear coated airbox cover/fake tank,
got home to realise it is now not running on one or both rear cylinders at idle, now the weather has turned really cold so can't go taking bits off, stupid weather :rolleyes:
 

Fire-medic

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took the bike out yesterday enjoying how it rode and pleased with my freshly clear coated airbox cover/fake tank,
got home to realise it is now not running on one or both rear cylinders at idle, now the weather has turned really cold so can't go taking bits off, stupid weather :rolleyes:
Pilot jets!

That's my opinion. The good thing is, if you know how-to clean them, it's a no-cost fix. If that's what it is, time for an inspection of the gas tank condition and replacement of the fuel filter. Before you discard it, try blowing-through it to check for the degree of obstruction, and then open it up to see what it collected.

I hear-you about the temperatures, it's 21 degrees C today, I might have-to slip on a sweater.
 

02GF74

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can't take my Vmax out until all the road salt is gone, so I have put some fuel stabil in the fuel tank to see if it stops gumming up or fuel deterioration, or maybe it's just a waste of money
Symptoms sound like they are due to block pilot jets - so the stabil failed to prevent that perhaps?

Somebody mentioned that undoing yje carb bowl screws is not that difficult so that may be a better option or having a switch to the fuel pump to turn it off whilst the engine is running in order to empty the carbs.

Let us know if it is blocked pilots.
 

Fire-medic

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Symptoms sound like they are due to block pilot jets - so the stabil failed to prevent that perhaps?

Somebody mentioned that undoing yje carb bowl screws is not that difficult so that may be a better option or having a switch to the fuel pump to turn it off whilst the engine is running in order to empty the carbs.

Let us know if it is blocked pilots.
Just unplug it, or clamp-off the line. Then-again how-hard is it to drain the float bowls with the drain screws? 'Lefty-loosie, times-four.' Drain. 'Righty-tighty, times-four.'
 

02GF74

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Fitting a switch to turn on/off the fuel pump could also be part of a simple security system if it is hidden and saves having to unbolt the seat to get to the fuel pump. ... but yes, if the drain screws are easily accessible and easily undone then agree that that's best.
 

Julian Tomkins

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I don't know if the 'stabil' did anything, I tried it as my bike had a similar problem after the previous winter wait, but that time the bike was hesitant on throttle openings but while still riding and waiting for the opportunity to get into the carbs the problem cleared itself, from then on I just enjoyed riding it and left every thing alone,
it's possible that the debris may have still been in the carb and has now recycled itself into the pilot jets again, or not 🤔
I have never taken these carbs apart other the the vacuum slides for new diaphragms, I did fit a new fuel filter about a year ago as the one on it was discoloured, the fuel tank is completely silver inside on the areas that are visible,
I am hoping to remove the carbs today as the weather is supposed to be warmer but I have to confess to being a bit nervous about it, my wrist is bad and I can not always apply the needed pressure to screwdrivers or even spanners sometimes so I am worried (maybe for nothing) about damaging the brass parts on removal if they are stuck, I did buy some 'repair' sets last year but I will not fit them after the writeups I've read about them, maybe the aftermarket jet gasket will be ok ?
I'll keep you informed,
oh yes when I first bought this bike it had a switch fitted to it that was just below the side panel, I found out by accident that it stopped the fuel pump, not fun when you don't know about it, so I removed it,
I am uneasy with draining the carbs for any length of time as the last bike I did that with (GPz750), all the rubber bits shrank and fuel leaked everywhere
 

Julian Tomkins

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weather people are wrong again so if I get the chance I might try the shotgun clean until it is actually warmer
 

02GF74

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According to the forecast, today is the warmest day until Thursday.

Some tips.
1.when undoing the clamps, don't undo the screw fully as the little spacer (to prevent overtightening) will drop out
2. Use a length of wood to lever off the carbs but be careful what you rest it on to avoid breaking something
3. Make note of how the cable joiner block goes together and where it sits
4. Should the screws holding the carbs together prove stubborn to undo, use an impact driver to undo but rest the opposite side on a block of wood.
5. If the screws are hard to undo, then you can get away with undoing 3, maybe 2 of them - I seem to recall separaring them into 2 pairs and rotating the bodies to access the bowls.
6. Use a blunt flat knife blade between the jet block and the gasket and work your way along to remove gasket without tearing it.
7. Use the blunt end of a drill bit inside the hole of the rubber bungs to fully seat them. The cut out segments face each other else they won't go in.
8. Use the thickest blade screw driver that fits into the holes to remove the jets.
9. Note down the numbers stamped on the jets
10. Work on one carb at a time so you can reference one of the undismantled ones to see how bits fit together.

Carb overhaul has been discussed umpteen times, it sounds daunting but is no single step is more difficult than removing the seat.
 

Julian Tomkins

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thanks for the tips, I have had the carbs completely off before to fit new inlet rubbers and I have taken many carbs apart in the past from singles to fours but not like the vmax ones, it's my ability to use the screwdriver in the correct manner now that concerns me, when your ability drops for what ever reason so do your confidence levels
 

02GF74

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Not great here either. Super weather to get a few miles in but first start after autumn failed dismally. The battery was more or less flat, charged it a bit, kinda wants to fire but won't. Maybe the stabiliser I added to the petrol has made it so stable it no longer wants to burn. May need to pull carbs off too :(

Given up as battery on the car gas had it (new one ordered) and it would take an hour or more to charge that - car needs to move out of the way so bike can get past.

Sometimes things go to plan, sometimes not.
 

Bill Seward

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Got new diaphragms and boot rubbers for Godzilla over winter. Waiting for a good day to get the bike out to the garage and have at it. I might be getting to you about a rebuild & cleaning, Dan... Gotta spend that stimulus check on something.....
 

Julian Tomkins

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well the weather actually got warm by early afternoon so I thought I'd drain the float bowls to see if anything was in there, there was barely any sign of bits at all so I thought I'd try the 'shotgun' procedure as time wasn't with me, and you know what, it worked, my bike is running lovely again, previously at idle the rear exhausts stayed wet when sprayed with water but now they burn and spit the water off like the front ones do,
I hope everyone else can get their bikes running nice too 🙂
 

Fire-medic

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Does one out of three count?
It does, if that's the one you're riding!

Shotgun/peashooter, good it they work, but I usually just remove the rack and split 'em, and into the ultrasonic tank they-go.

Glad you got the easy-fix to work.
 

Julian Tomkins

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I'm sure I will eventually have to strip them for a proper clean but if they can stay good through a simpler method at least until the weather is warm and stable then I'm happy
 

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