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engine dies when opening throttle?


tooty
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Hello i hope someone out there can help me. Ihave an xj900 "89" which starts and runs on choke (sounds sluggish) but engine stops if i remove choke or make any attempt to turn on throttle. If it helps i have replaced float needles and seats, thoroughly cleaned everything including all jets and emulsion tubes, non of this has made any difference, i also have checked though each diaphram all seem as new. What is it iam missing?????? thanks tooty.

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This sounds very similar to my Serow with a faulty CDI unit, try checking the loom plugs that hold the CDI wires together, give them a clean just in case. Any chance of borrowing one to try from a mate? I'd also be tempted to look at the flywheel end of the electronics, clean out the dust and rubbish, etc. Two longshots but you have done the most likely so it is time to look at the less obvious stuff.

Good luck,

John

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This sounds very similar to my Serow with a faulty CDI unit, try checking the loom plugs that hold the CDI wires together, give them a clean just in case. Any chance of borrowing one to try from a mate? I'd also be tempted to look at the flywheel end of the electronics, clean out the dust and rubbish, etc. Two longshots but you have done the most likely so it is time to look at the less obvious stuff.

Good luck,

John

Thanks for replying iam about to go on nights so it will be a day or two before i get chance to try your suggestion, heres hoping. many thanks.

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Could be a rich cut or there is still something wrong with the fuel system. Is there enough fuel coming out of the tank?

Thanks for getting back, all i can say is i think the fuel delivery is fine but i will make the effort to check more thoroughly many thanks.

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Thanks for getting back, all i can say is i think the fuel delivery is fine but i will make the effort to check more thoroughly many thanks.

Hi

Have same problem on my kawa at the moment - but I am fairly sure it's a fuel mixture problem - when you open the throttle the mixture goes weak and the engine dies. Are you using a standard airbox etc - you could also check for air leaks on the inlet side of the carb, check your float heights etc. My experience with dying on acceleration on 'normally aspirated' engines is that it is nearly always a fuel problem. The only way of really checking the CDI/igniter etc is to put in a 'good' unit and seeing if it makes a difference.

Let us know how you get on.

:D

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Dude if you have to use the choke that makes there more fuel then air. Since you wont run without the choke, you're too lean. Go to a parts fiche for your bike and buy the STANDARD jets for the bike. Your local dealer should have them in stock as they are a generic part.

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Thanks for getting back, all i can say is i think the fuel delivery is fine but i will make the effort to check more thoroughly many thanks.

HI there thanks for replying, i have changed float needles and seats, checked the action of the floats but how can i check the float hights effectively,? i can say the floats lift and fall opening and closing off the fuel but as to the hights being right or wrong, how do i check?? however iam satisfied the fuel delivery to the carbs is ok so thats something i guess. look forward to your reply many thanks speak soon tooty

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Hi

Have same problem on my kawa at the moment - but I am fairly sure it's a fuel mixture problem - when you open the throttle the mixture goes weak and the engine dies. Are you using a standard airbox etc - you could also check for air leaks on the inlet side of the carb, check your float heights etc. My experience with dying on acceleration on 'normally aspirated' engines is that it is nearly always a fuel problem. The only way of really checking the CDI/igniter etc is to put in a 'good' unit and seeing if it makes a difference.

Let us know how you get on.

:D

Hello fosdyke, thankyou for your reply, i have had a 98% improvment by tackeling the pilot jets, they were all gummed up i shyed away from them until i could locate a suitable manual, i have done this before without a manual and lived to regret it. However i think the remaining problem is now down to adjustments. It starts on choke and runs with full throttle movement, it runs off choke also with throttle but wont idle for long before revs start to drop off. Still it is a massive improvement, iam very encouraged by this. Thanks again for your input and to all those who took the trouble to reply to my calls for help, cheers tooty

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