spluttering at 6-7k rpm in second upwards!

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CRM
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Re: spluttering at 6-7k rpm in second upwards!

Post by CRM »

lol, not too far from me then.
i live 5 mins from maxton, 5 mins from Jcn12 M56
If the things legal and rides of a sort, welcome to fetch it over here sometime and i know these things pretty well after all these years.
How does it run from cold ?
does it run better when cold or warm.
does it get worse as it gets warmer - longer you ride it.
it it brick wall shit running, or varying - ie sometimes, some gears ok, other times really bad regardless of gear / speed
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Chesh
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Re: spluttering at 6-7k rpm in second upwards!

Post by Chesh »

yea its legal to ride. Its great for about 20 mins, revs through every gear no problem then it'll start choking up in second at about 6000 but will go past it if i ease off and let it slowly accelerate past it and then the other gears it will splutter the more i give it.

Are you free tomorrow? I'm off and I really want to enjoy the bike I've had enough of it. Been sorting it since last monday, been problem after problem.
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Re: spluttering at 6-7k rpm in second upwards!

Post by CRM »

tell you now what it is - get a new set of plugs and i bet the problems vanish. if they dont i bet you have a coil failing when hot / under load.
no i work will 7ish and work in chester, prob around bits of the weekend though. got to take the Ducati over to wales and bring a 400 back, so sunday PM will be around.

get a new set of plugs tommorow, rears are a doddle to do, but i bet it will be the fronts (no one changes them as they are hard to reach without the factory tool)
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Re: spluttering at 6-7k rpm in second upwards!

Post by Chesh »

I changed them yesterday. It's only just started doing it 2 days ago. It'll been running like a dream for the past 9 days.
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Re: spluttering at 6-7k rpm in second upwards!

Post by CRM »

Before you changed them?
Also is the charging sys ok? 13.5v or more at 3k
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Re: spluttering at 6-7k rpm in second upwards!

Post by Chesh »

It was doing it before i changed the plugs. I'm thinking it is more electrical. I'll give all the terminals a good scrub to make sure the resistance is low. I haven't got a multi meter so can't check the charging system.
The bike has cut out twice while riding and the battery has gone completely flat when I try to start it again. The alternator rectifier is working as I get a full charge after bumping and riding for abit. I don't get this problem when i disconnect the lights that hunts gave me (double the power of the originals).
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Re: spluttering at 6-7k rpm in second upwards!

Post by Cammo »

Chesh wrote:I don't get this problem when i disconnect the lights that hunts gave me (double the power of the originals).
It sounds like the charging system is struggling to provide adequate voltage to the plugs. Get a multimeter (cheap) and conduct some checks.
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Re: spluttering at 6-7k rpm in second upwards!

Post by magg »

Recommend that you check your battery voltage with the bike running at idle and 5000 rpm. If the battery is going flat there may be a problem with the charging system and this could affect the ignition and thus result in poor running.
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Re: spluttering at 6-7k rpm in second upwards!

Post by thunderace »

Chesh wrote:It was doing it before i changed the plugs. I'm thinking it is more electrical. I'll give all the terminals a good scrub to make sure the resistance is low. I haven't got a multi meter so can't check the charging system.
The bike has cut out twice while riding and the battery has gone completely flat when I try to start it again. The alternator rectifier is working as I get a full charge after bumping and riding for abit. I don't get this problem when i disconnect the lights that hunts gave me (double the power of the originals).

I wish you'd said all this in the first place matey ;)

Nip down to the shops and pick up a cheap multimeter. Even some Pound shops sell them now :peace: Or Tesco have one for about a fiver.

As Paul said, it does now sound like a failing coil could be causing the running issues. My advice for this issue would be to ditch the coil packs and HT leads altogether and opt for a stick coil conversion.

However, that doesn't fully explain the fact that the headlights are wankering the battery so the reg/rec could still well be fubar or the generator may have gone a phase down. Also check to see if the relay mod has been done as I suggested before.
Conventional wisdom says to know your limits. To know your limits you need to find them first. Finding your limits generally involves getting in over your head and hoping you live long enough to benefit from the experience. That's the fun part.
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Re: spluttering at 6-7k rpm in second upwards!

Post by Chesh »

right! Today I checked all the electrical connections for corrosion and cleaned them all like new, I then disconnected the battery so the ECU can reset it self as some cars when they go into limp mode they have to be reset.
While doing this I also gave the air filter and carbs a good doing over and it works like a dream now!

Gave it a good 4 hour test ride and it didnt splutter once! well apart from when I had to go on reserve fuel lol.

The only problem I have left now is coolant is dripping out of the overflow pipe. I've changed the cap, took the thermostat out too to see if that was causing it. I've since put the thermostat back in as it didn't effect it at all. But when I changed the cap that has stopped it alot but every now and again some does come out. I've back flushed it too.

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