ZXR 750 J1 Help

[RickTaff]

Meant to MOT bike today, so started her up, let her warm up on various levels of choke, until choke off. Temperature gauge needle was on the first red notch and she was idling ok, nice consistent note. (with choke off) The odd pop in the exhaust when she first started; but nothing out of the ordinary

So jumped on the bike, clutch in popped her into first, clutch out - found the bite point, but soon as i rolled on the throttle she died. Every single time. I think i even tried opening the throttle first and holding it at a steady RPM, for example say, 4k, and then found the bite, but as soon as the bite was found..... revs dropped like a stone and it cut out again

Im not the most mechanically gifted when it comes to bikes and have had 2 suggestions which i wanted to run by you guys, see which would you'd lean towards

1. Clogged main jets. [however some google searches reveal bike would idle really rough, if at all, if these were clogged]

2. Dodgy side stand switch

But I have had the bike on a paddock stand, roughly 2 months ago, with rear wheel in the air going through the gears, and it didn't cut out at all then when releasing clutch and rolling on throttle

[MarJay]

It's not main jets, you don't come on to mains until the throttle is over about 60%. If it were pilot jets, the bike would give a lumpy idle. If it were sidestand it would probably die as soon as you put it into 1st rather than when you let the clutch out.

It's quite a weird one. Is there a clutch interlock? Do you need to pull the clutch to start it? (probably not on such an old bike).
____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[jaffa90]

If the bike free wheels then give it more fuel or less air (unwanted air) under load.

[Nobby the Bastard]

Is it firing on all cylinders? It doesn't sound like a fueling or interlock issue.

I'd suspect your only on 2 cylinders because either a plug, lead, cap or coil has failed
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trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[Ste]

I'd have a look at that ram air hoses as if one of them has become loose then the bike would do something like what you're describing.

[RickTaff]

[RickTaff]

[RickTaff]

[Nobby the Bastard]

Was it working before?
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[RickTaff]

[Nobby the Bastard]

Okay. It could be anything that has been ballsed up for a while.

To discount spark issues. Spray water onto the exhaust headers within a few seconds of starting it from dead could. If there's an issue there a couple of pipes will take a few seconds longer boiling off the water.

Sounds like you've been sold a dud, though.
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trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[RickTaff]

[oilyrag]

Try pulling away on the choke

[ThunderRat]

Try it with the fuel cap open. May be an air lock.

[RickTaff]

Cleaned all main and pilot jets with carb cleaner and compressed air, all clear and able to see through them. No blockages.


Bike started fine, let her warm up with various levels of choke and still the fucker will not let me open the throttle in the bite zone. Bogs and really flat response from throttle.

My only other suspicion now is air/fuel mixture. Have the manual so will see what its factory setting is meant to be, otherwise im stumped.

Did notice the odd little flame popping out of my exhaust, and odd backfire, maybe that is mixture related?

[jeffyjeff]

[MarJay]

Is the choke definitely off when you try to ride it? Does the bike start without choke?

I wonder if the choke is stuck on, or the choke plunger is damaged or something like that?
____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[Robby]

Do these have a fuel pump?

[RickTaff]

[RickTaff]

[MarJay]

[RickTaff]

[to v or not to v]

congrats on sorting it out

[RickTaff]