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Blade carbs puking fuel
chrisf - 28/8/05 at 09:48 PM

OK Gents:

I can start my blade engine just fine. One press of the button and she jumps to life. It will run for a while, maybe 30-40 seconds, then sputter and die. Then, fuel starts dripping out from what looks like under the carbs. After 10 seconds or so, it starts puking out the top breather!

The gent I bought this from had it tuned on the dyno (in a car), so I'm pretty sure the carbs are optimized. I also bought a 99-02 R6 fuel pump. My assumption was that most carbed bikes used the same fuel pump.

Any ideas folks?

--Chris Rescued attachment Question.jpg
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chrisf - 28/8/05 at 09:48 PM

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Brooky - 28/8/05 at 10:15 PM

It looks like your needle valves arent shutting off the fuel to the carb. Asthe carb bowl fills, the float rises and the needle valve should shut the fuel off.
Take the carbs off and remove the bowls ( marked as puke here initially ) and make sure the floats arent sticking and the needle valves aren't worn, give it all a good clean and then retry them.
Just had the same problem with mine and needed new needle valves.


bigrich - 28/8/05 at 10:26 PM

i initialy had the same problem which i put down to the blade carbs being gravity fed on the bike and pump pressure being a bit to much for the needles to cope with. Sorted it out with a pressure reg with no problems since. (98 rrw blade)


david cromie - 28/8/05 at 11:51 PM

Had same problem, I use the Blades own pump. Whwn I started up you could hear the pump ticking away and did not stop. Fuel everywhere. Took off carbs and cleaned and used airline down the fuel ways. Checked needle and seats and all well. Built it up again and all well. Made a long overflow pipe to run to the botton of the car just in case it started again and the fuel would be sent out of harms way. It appears that when blade carbs. are left dry for some time this happens. Hope this of some help. Davis


shortie - 29/8/05 at 06:56 AM

I might be wrong but that looks like a pump off a fuel injected bike which will pump fuel at far too high a pressure to the carbs.

You need a pump off a carbed bike which will pump to between 1-2psi and then shut off.

HTH,
Rich.


chrisf - 29/8/05 at 01:22 PM

Thanks for the suggestions guys. The fuel pump is from a 99-00 R6. I looked around on the web and found that the r6 of those years used carbs. Hopefully, this is true. I agree that is initially looks like a fuel pressure problem. However, aren't most fuel injected bikes' fuel pump in the tank itself? Also, don't FI pumps use an enormous pressure? I would think the fuel would always squirt out.

So I'll try cleaning the carbs out before I replace the pump. Does anyone happen to have a scan of the manual where they document carb cleaning? I have no idea how these things work!

--Thanks, Chris


mad-butcher - 29/8/05 at 06:41 PM

also had a similar problem using a facet pump. to double check it was the pump at fault i made up a header tank and gravity fed the carbs no overflow so i then knew the valves were seating
tony


andy d (rizla) - 29/8/05 at 07:31 PM

get a 98 r1 pump,works perfect,i had problems with mine spuing fuel out all the places you do,this pump cured it instantly,and only £11 on e-bay


Peteff - 29/8/05 at 08:18 PM

Are the float chamber bleed screws done up?. That's the only place under mine where fuel can come out.


chrisf - 29/8/05 at 08:36 PM

I should think so, but then again, I have no idea! This is the first carbed car I've owned. I have no idea how these things work. I'm hoping to get a scanned page of the Haynes manual telling my how to do this.

I'll pull the carbs tonight and have a look.

--Thanks, Chris


the_fbi - 29/8/05 at 08:38 PM

quote:
Originally posted by chrisf
Does anyone happen to have a scan of the manual where they document carb cleaning? I have no idea how these things work!


For a 99-02 R6 carb.

http://www.ukcartuning.co.uk/r6/carb.pdf
or if that doesn't work
http://65.98.67.210/~ukcart/r6/carb.pdf


the_fbi - 29/8/05 at 08:43 PM

FYI the R1 1998 fuel pump was 20kPa (0.2bar) pressure.

Could just see what sort of pressure you get from the pump when its off the carbs.

The R1 FI pump I have is
294kPa (2.94bar, 42.6psi) so you'll soon know the difference. If you can block the flow its a carb pump, if you struggle (and get very wet) its a FI pump.


the_fbi - 29/8/05 at 08:49 PM

Further, this is my R1 FI pump, which looks remarkably similar to your "non FI" pump. I think you may be overfuelling



Just try gravity feeding the carbs and see how it goes.

EDIT: Just noticed from the manual, the carb pump is a Mitsubishi, the FI pump is a Denso unit.

[Edited on 29/8/05 by the_fbi]


chrisf - 27/3/06 at 02:34 PM

OK, my carbs are still slightly puking fuel at idle. I still think that it is the carbs, but I'm willing to try a new fuel pump. Does this fuel pump look like it will work for a 919 fireblade?

Also, I used 3/8" fuel line to the carbs. Is this perhaps too big and causing the trouble?

If I do indeed have a fuel injected pump, would I not know immediately? The FI pumps flow fuel at huge pressures. I would have thought all sorts of fuel issues would be manifest...

--Thanks, Chris

[Edited on 27/3/06 by chrisf]


Jon Ison - 27/3/06 at 04:11 PM

Provided its not an injection pump its the carbs, regular occurrence if they have been stood a while, stuck floats, they operate at such low pressures they can easily stick with the slightest of gunk on them, that's why if standing for a while the carbs should be drained, tap it on top gently with summat, short term fix, long term, clean em.


mkblade - 28/3/06 at 11:27 AM

it does sound like the carbs sticking,take them apart clean them with carb cleaner.

i also put a facet pump and fuel reg on my blade engine i got the bit from mac 1 about £60.00
hope this helps


chrisf - 28/3/06 at 12:13 PM

Thing is, I've disassembled and cleaned a few times now. I'm off to Honda today to buy some exhaust gaskets. I'll pick up a couple of new needles and see if that fixes the problem.

Surely this isn't part of routine maintainence for these things...

--Chris