Bimota Forum

oily · Joined: 05 Apr 2008 Posts: 4788 Location: worcestershire

After finally getting this SB6R sorted and ready for MOT, I decide to give it a blast around the block and HORROR, there's the biggest flat spot I've ever come across. After stripping all the bodywork off and breaking into the air box, I find the previous owner has completely disconnected/bypassed the fuel pump. I've only ever had it running on the stand before and it's been sweet as a nut, but when you give it a huge handful on the road, it almost cut's out from fuel starvation I'm guessing so gravity feeding the fuel probably isn't enough. I've pulled the pump out and it's got one inlet, two outlets and a vacuum connection. It's a WELBRO ENGINE MANAGEMENT pump with the numbers FPA-2 0227 stamped on it. I've googled it and got no joy. Anyone know anything about these and why would it have been bypassed and should I just fit an electric pump. I very vaugly recall a problem with the early SB6R's that the carbs overflowed on tick over, could this be the reason. In any case, HELP Shocked

Admin · Posted: Fri Nov 07, 2008 12:30 am Post subject:

Hi

I have vague memories of hearing of lots of odd problems with the fueling on the SB6, with the pump being part of the problem. Cannot remember for certain, but think it managed to massively over fuel the carbs at either low revs or high revs.

All the best

Keith

oily · Joined: 05 Apr 2008 Posts: 4788 Location: worcestershire

UPDATE:
I've now pulled the carbs and stripped them. The only problem is, I don't know if anyone has messed with them before, I assume they have as the main jet's are 150 where bimota states thy should be 120. A massive leap in size. The float heights were 11.5, Bimota say they should be 14.7. Slow running screws were set at 1.25 turns out, Bimota state 2 full turns. Needle clips in 4th groove, Bimota state 2nd groove and so on and so forth. I've stuck 120 main jets in and set everything else to factory settings and I'll whack em back on later and see if it'll fire up. If anyone has got a set of carbs for sale, SHOUT up. I need to get this thing up and running so I can get on with other projects. Wink

Pompey · Joined: 31 Jul 2008 Posts: 2311 Location: Marlborough

he must have had a lot of air pushing through for that set up? Maybe he had an industrial fan on the front and a pair of peddle bins for exhausts! I have a mate who's ex bsb mechanic on suzuki's... I'll see if he recognizes the set up?
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Pomps
Bimota's Db2, Db5 ,Ducati's 851' 92, 888' 93, Honda blade' 93, Triumph speed triple' 07, kawasaki zxr 750 k1

oily · Joined: 05 Apr 2008 Posts: 4788 Location: worcestershire

Good man, Thank's.
Just tried to fire it up on 120 main jets and 14.7 float height. Tries to fire but just don't quite make it. At least it would start and tickover sweet before. Which is wrong, the float height or the main jets????????????
Any one want a SB6R before I torch it?
Any one know who can sort this out in the midlands? Confused

madasfook · Joined: 16 Jul 2008 Posts: 221 Location: sunny south west

with the flot hight that low and the jet that bigi m not suprised it had a flat spot , i think you will find that it was just running on the pilot jet , witch is fine on tick over but no go on full chat , im only saying this as i had a bike that would start and run fine but as soon as you gave the throtle a blip it would die , and it turned out to be water in the carb float chamber
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so many toys so little time

madasfook · Joined: 16 Jul 2008 Posts: 221 Location: sunny south west

best bet is to re set it to standard , or get a second hand set of carbs , cant cost that much as it is only crapy old suzuki Very Happy

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so many toys so little time

madasfook · Joined: 16 Jul 2008 Posts: 221 Location: sunny south west

just had a second thought Shocked

it may have been set bigger due to a fuel flow problem with the pump or did you think of that
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so many toys so little time

oily · Joined: 05 Apr 2008 Posts: 4788 Location: worcestershire

oily · Joined: 05 Apr 2008 Posts: 4788 Location: worcestershire

madasfook · Joined: 16 Jul 2008 Posts: 221 Location: sunny south west

a non runner Exclamation

cant be worh more than a bag of sand Laughing

i might be able to take it off your hands as i did not get that YB8 frame and bits due to to many parts missing , and i have a space inthe workshop as one of the R1s may be going today Very Happy

any way what are you doing up at this time of day i thought it was only me working at this silly hour Rolling Eyes

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so many toys so little time

oily · Joined: 05 Apr 2008 Posts: 4788 Location: worcestershire

Been up all night working. I'd like to say, On the Bimota, but that would be a lie or I could say, couldent sleep cus I've been worrying about the bimota, that would be a lie too
A bag of sand is less than £4 Shocked

I'd want a little bit more than that Wink

I'm gonna try and get hold of a set of carbs before i do anything else, the carbs I've got are too much of an unknown quantity and buying all new jets and things is gonna knock a hole in a ton, so I might as well blow it on an un-messed with set.

oily · Joined: 05 Apr 2008 Posts: 4788 Location: worcestershire

Result, after being quoted nearly £150 for all the jets for the carbs, from Suzuki, I've shopped around the intanetthingi and got them all for £30. What a wonderful thing Laughing

Should be here in the morning and then we'll see if this beast is gonna live or die Wink

Pompey · Joined: 31 Jul 2008 Posts: 2311 Location: Marlborough

Hey Oily, you need to film it running in all its glory and post on youtube so we can all breath a collective sigh of relief! x
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Pomps
Bimota's Db2, Db5 ,Ducati's 851' 92, 888' 93, Honda blade' 93, Triumph speed triple' 07, kawasaki zxr 750 k1

oily · Joined: 05 Apr 2008 Posts: 4788 Location: worcestershire

Let's get it running first Laughing