RF400 lacking fuel?

[Dark Crystal]

Hi all,

It started like this... was out west riding around, and all of a sudden my RF feels like she's running on 3 cylinders... then she fired on all 4 and got me most of the way home and started running like shit again... at home i found that one of the spark leads had some how desided to remove it self from a #1 sparkplug. Upon connecting, she went sweet.. for about half an hour.. it'd idle then when i revved it would pretty much die.. it was doing that yesterday (not ridable)... and now it won't even start.. it's like she's lacking enough fuel... she wants to start... but not quite enough to idle.

iv'e checked:

sparkplugs (gaps, cleaned)
fuel flow from tank
cleaned contacts in leads
tried on both 'on' and 'reserve'
Charging fine
Airfilters fine

any help would be appreciated... in all honesty i haven't pulled the carby's apart... but figured that even if a little dirt got into one of them, it'd still fire enough to idle rougly...

Matt

[Warr]

Watching thread as my daughters 400 Bandit does the same.
Her theory is keep the tank full as it seems ok then.
But I have had the tank off and the tap out and petrol runs fine.
I havent checked that the tank is breathing, like breather could be blocked ?? and not letting air in.

[Madness]

Not familiar with the bikes, do they have a vacuum petrol tap?

[Drum]

Not familiar with the bikes, do they have a vacuum petrol tap?

I had the same initial idea. Is there a "PRI" setting or similar on the fuel tap? Still, that wouldn't explain the bike coming back to life when you reattached the spark lead.

[Dark Crystal]

The fuel tank breaths through the filler area.. i tried starting her with the cap open too... but no go... besides, fuel pours outta the tap when i take the hose off, so alls sweet there... no 'pri' setting either.

Thinking after having a real good search on these forums that i'm gonna have to pull the carbs apart and check needle valves/float levels... that's gonna be fun

[Warr]

... i'm gonna have to pull the carbs apart and check needle valves/float levels... that's gonna be fun

I dont know bout doing that just yet.
Are you sure you have a spark. Take at least one plug out. Is it/ are they dry?

Is the ignition working ?
With one of the plugs you have out rest it against the head and spin it over on the starter. Is it firing ?

The carbs probably have a bleed screw at the bottom of the float bowl. Unscrew each one and see if it runs clear fuel. You could have water or other rubbish in the bowl's but flushing it should be sufficent to clean it.

If there is brown rusty stuff or water droplets best when she is all going before you go on a good ride put a cup of meths in the tank. This will disolve any water and send it through to the carbs and be burnt as per normal. I understand meths isnt so good for the fuel lines so that why you want to flush it all through on a ride.

[Dark Crystal]

Okay... so far tonight iv'e checked the ignition system..deffiitly have suffiecient spart on each cylinder..

My carbs don't seem to have a bleed screw underneath to drain

What about the fuel pump?? Any ideas how i can test it?

[Mr. Peanut]

Drain your carbs, and add half a cup of meths to the tank.

[Dark Crystal]

Okay... now iv'e removed the air box and put it back together again, drained the carbs, checked the fuel filter... she ain't firing... she's got spark, but not firing... this is getting weird.

[Warr]

Okay... now iv'e removed the air box and put it back together again, drained the carbs, checked the fuel filter... she ain't firing... she's got spark, but not firing... this is getting weird.

Are the plugs wet ?

[madmal64]

I know nudemetalz is or was having a similar problem with his RF400 too. Might be worth doing a thread search here to see what you trawl up.

[madmal64]

Here ya go
http://www.kiwibiker.co.nz/forums/sh...ighlight=RF400

[Dark Crystal]

I managed to get my RF400 going again... but it shat itself again too... on Friday night i gave her another clean of all the above i had already done, and she started... rough for about a minute, then perfect until i turned her off.. so yesterday i thought i'd take her for a ride... she started fine, then crapped out half way down the drive way... she was still running though just coulden't rev her.. everything is working how it suppose to be.. so now my thoughts are this: i'll replace all the spark plugs on Tuesday (payday) coz i'm thinking #1 was under a bit of stress with the plug off.. iv'e also drained the carbs again and have just completely emptied the tank.. i'll fill her up with fresh 96.

Please don't let this put anyone off buying one of these bikes, they are great bikes, just having a few problems which i believe i caused my self!

What plugs would you recommend??? It has NGKCR7E in there now, but a website selling the plugs mentioned NGKCR9E...

[Dark Crystal]

Yay i fixed the little f*&ker... i mean the sweet beautifull thing..

I rang a Honda dealer in East Tamaki (he was closer to me that in town).. he asked what sort of bike... and what fuel i'm running... i said 96. That's ya problem he says... he reckons 96 is thicker than 91. So i emptied the tank and filled her with 91, drained all the fuel lines too. Before i started her up, i pulled the carby's off and cleaned the bowls and all jets.. although there didn't seem to be any obvious clogging at all, just a smidgen of dirt by the drain screw. Put her all back together, and she purrs like a kitten... like when you pour water on a kitten... ha ha!

I have another post in here too, so i'll copy and paste this post on that one too...

Cheers for all the help people!!

Matt

[bistard]

Thats abit strange,I have never heard the theory that 91 & 96 have a different viscocity that would be enough to stop it running,sounds like bullshit to me,but,hey if it fixed it!!