2004 GSX250 stalling at 100kph?

[theGSXRJedi]

Hi Everyone, I need some help. I have an 04 GSX250 I have had it for 4 years, but now it is coughing and spluttering, then stalling, this usually happens in the morning on my way to work while im at 100kph. on a nice warm day it runs like a dream, doesn't skip a beat.

it has recently been serviced, new oil and plugs, I cant find air or fuel filters anywhere. 23,000ks on the clock, I have had the carby apart and cleaned jets and such but to no avail.

any insight would be greatly appreciated.

[ital916]

That is an odd one. Might need to do a bit of testing. Next time is starts coughing, clutch in and give it a bit of revs to see what happens. If it's working fine on a warm day....doesn't sound like a fuelling problem. Does the bike restart easily? Or does it struggle to turn over?

[theGSXRJedi]

Tried that, clutch in and it stalls. press starter and it fires up no trouble. at first I thought it was the kill switch on the stand because it was loose, fixed that but problem persists. it really is doing my head in.

[AllanB]

Check fuel cap breather is clear.

I really suspect you have hit top speed bawahahahahaha

[xXGIBBOXx]

The fuel filter you can use is a ryco z676 or z675 . Can't remember which one . ( 7/16 hose I think ) and yeah the air filter are like hens teeth . Just put pod filters on it and enjoy the intake roar

[tigertim20]

Check fuel cap breather is clear.

I really suspect you have hit top speed bawahahahahaha

yup check the breather

[theGSXRJedi]

Thanks guys. Will do pod filters and check fuel cap breather.

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[theGSXRJedi]

Where the filter mounts to the throttle body is oval, 57mm at its widest, 52 at its narrowest, will a 60mm filter fit securely?

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[theGSXRJedi]

Fuel cap breater is clear too

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[theGSXRJedi]

Lol breather

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[F5 Dave]

Don't fit pod filters, it will never run right again

[theGSXRJedi]

Don't fit pod filters, it will never run right again

Really? Where else should I start looking, to find the cause?

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[F5 Dave]

Changing the airfilter to another that flows differently will mean you need to change the jetting. Considerably.

Pod filters were popular in the 80s when airboxes were dreadful, but while they increased airflow they screwed up the fueling, businesses sprung up to create jet kits for such conversions with new air corrector jets, mains pilots etc. Nowadays there isn't much to be gained but lots to lose.

Either way, if your bike is running fine sometimes; it isn't the airfilter. The fact it will start up straight away means it is unlikely to be electrical. . . .but it is a Suzuki so bang a multimeter set to volts over the battery & rev it seeing that it does not get to 15V. If it does you have a problem there.

It must be fuel starvation. There is enough to keep it running except under higher load, hence why it happens at 100k. Colder days require richer mixture. If it is borderline starving that may explain why it will keep running on warmer days, but I wouldn't have picked it.

Either way; on the couple of different bikes I've had that have done this it has been starvation due to a badly placed inline fuel filter that creased the fuel line. If there isn't one fitted I'd still consider looking at the fuel lines & considering replacing them with proper lines if they look suspect. As you can imagine the small hole in the line gets real thin if you kink the tube just a little.

Also consider if it has a vacuum tap (on tank) fitted that it is working properly.

They have a small tube running to the inlet manifold or to the carbs You should be able to open the tap by sucking on this line gently (no fuel in this section). Actually check the tops of the carbs, they have rubber bungs fitted for doing balancing. Check none have come off.

[theGSXRJedi]

Changing the airfilter to another that flows differently will mean you need to change the jetting. Considerably.

Pod filters were popular in the 80s when airboxes were dreadful, but while they increased airflow they screwed up the fueling, businesses sprung up to create jet kits for such conversions with new air corrector jets, mains pilots etc. Nowadays there isn't much to be gained but lots to lose.

Either way, if your bike is running fine sometimes; it isn't the airfilter. The fact it will start up straight away means it is unlikely to be electrical. . . .but it is a Suzuki so bang a multimeter set to volts over the battery & rev it seeing that it does not get to 15V. If it does you have a problem there.

It must be fuel starvation. There is enough to keep it running except under higher load, hence why it happens at 100k. Colder days require richer mixture. If it is borderline starving that may explain why it will keep running on warmer days, but I wouldn't have picked it.

Either way; on the couple of different bikes I've had that have done this it has been starvation due to a badly placed inline fuel filter that creased the fuel line. If there isn't one fitted I'd still consider looking at the fuel lines & considering replacing them with proper lines if they look suspect. As you can imagine the small hole in the line gets real thin if you kink the tube just a little.

Also consider if it has a vacuum tap (on tank) fitted that it is working properly.

They have a small tube running to the inlet manifold or to the carbs You should be able to open the tap by sucking on this line gently (no fuel in this section). Actually check the tops of the carbs, they have rubber bungs fitted for doing balancing. Check none have come off.

Wow thank you. I will not do pod filters as suggested, I have re cleaned the jets, will replace the fuel lines, filter and clean tank breather. Let you know how it goes when I run it after Christmas. Your input was really appreciated cheers.

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[Jjgres]

Has to be a fuel filter in there somewhere. Maybe inside tank on petcock or tiny plastic ones in Carb fuel inlet?

[theGSXRJedi]

Has to be a fuel filter in there somewhere. Maybe inside tank on petcock or tiny plastic ones in Carb fuel inlet?

There is a fuel filter. Having trouble finding a new one though.

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[frogfeaturesFZR]

If it's in the fuel line any generic petrol filter will do.
Was there a 'mesh' in the fuel petcock ?

[theGSXRJedi]

Problem solved, was a bad CDI box.

[F5 Dave]

Urgent. Check voltage when running as described. Common failure and takes out cdi.

[FJRider]

Problem solved, was a bad CDI box.

Get the Air filter sorted ... otherwise it's running lean.

ANY filter is better than NO filter ... re-jetting isn't a big issue if you pay professionals to do it.

Small changes/faults affect small bikes in a BIG way ...

[theGSXRJedi]

I checked voltage its between 14.2 to 14.4 throughout the rev range, tested at the battery. Have found filters now too

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[F5 Dave]

Sweet. .

[theGSXRJedi]

Cheers for your help F5 Dave you are a champion

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