Cough and splutter!!!
 

While riding along and sticking to a constant speed if I suddenly want to put the power one my 996 coughs splutters then eventually takes off, the bike has been on the dyno and has a very smooth power curve but it is running too rich (apparently). I was told it could have something to do with the pots!!!!! (I got lost at that point and started to sing to myself in my head).

Any ideas and is it expensive?

Cheers
Dave

is it a twin injector ?
could be that if fits in the mid range ?

Do you want the truth......it's a 1999 996!

I couldn't tell you, I'm not that familiar with the bike yet:puzzled:

well a couple of things then.
has it always done it ?
is it an adjustable chip ?

I've had the bike for almost a year and it has done it since then.

It has been serviced in the last 2 months (12k) and a new chip was installed (996 s) which is not adjustable.

if i were you then i would get an adjustable chip (ultimap) then have it put on the dyno then they will be able to sort it out.
you said you were told it was to rich but they cant do much about it as its not adjustable, should make it a bit more lively too

cheers mate.

oh how much for the chip?

£100 - £150
try Nelly or Neil at sigma

It's just cost me £70 for the 996 s one:(:(:(

keefer got it first!

Dual Injectors/Single Injector Conversion

All 996's came with two injectors per cylinder. Before the 996 model, only the SP and SPS bikes had dual injectors. However, those earlier bikes use the larger P8 computer which is capable of firing the injectors sequentially, meaning the second injector sprays only at the higher engine speeds.

The 996, on the other hand, is controlled by the smaller 1.6M computer which is incapable of firing the injectors sequentially. So the engine does not run well with both injectors firing at the same time, especially at low rpms where spray durations get too short to get good spray patterns. The fuel dribbles out.

According to FIM, dual injectors are not needed unless you're making more than 120HP, and so have developed a single injector chip for the 996.

Read more about it here:
http://www.moto-one.com.au/performance/996eproms2.html

This is a quote from FIM's site:

"We have two UltiMaps for the 996 Biposto '99/2000 model. There have been many problems with these models spitting on low throttle or cruise at low speeds. We have finally made a chip which cures the problem (type UM222), but requires that one injector be disconnected from each cylinder. This is because the 996 has two injectors hard-wired in the harness and we can't switch one off like we can with the 996SPS or early 888 computers. The benefit is that the single injector spits more cleanly at low durations than two injectors do ( because they have only half the time each) and idle and low throttle repsonse is heaps better. We remapped a 996 with this mod and the difference is incredible. We do sell a twin injector verison of the same chip (type UM221), but in most cases the UM222 works better, and is worth the effort."

[Edited on 5-20-2005 by Shazaam!]

I have the FIM/Sigma single injector mod on my 996 - well worth it.

pc3 ? that might sort it :cool:

Can you just unplug the second set of injectors?

That's where it can start to get expensive though:(

Dave,

A PC3 is definite overkill mate, I'm with TP on this, I have the FIM/Sigma single chip and the bike now runs a dream (Y2K 996) and used to suffer like yours. Also you don't need dyno time to set it up, it's done with a hand held reader that the suppliers have ...... Nelly can supply & fit and has tweaked mine in the past and Sigma can supply and fit also as thats where mines from.

Good luck ...

Cheers Dibbs, that sounds like the answer to me, is this the chip that'll cost around a ton?

yep, still waiting for mine to turn up from Nelly

Yep, and its what you should have been sold in the 1st place rather than the non adjustable 996S chip... an expensive lesson unfortunately ... I'd go back to them and tell them that what they sold you hasnt solved the issue ....

Keefer, he's at the BMF, I'm sure it'll be with you soon ...

yea I know, wasn't having a moan just saying get in line :lol:
Nelly has been really helpful while I have been putting the 996 lump in.
top bloke :eureka:

So does this problem happen on 998's too ?

Reason I ask is that I've not noticed this on my 2001 996, but the 998 'hunts' if cruising along at around 5k rpm, and will also splutter a bit after doing this, sometimes going down onto one cylinder (well it sounds & feels like it).

I have a powercommander to slap on it, but not fitted it yet.

Never had any problems with my 998 with the 54mm system and ECU

I think mine has a 54mm system & ecu too (I say 'think' as the box the standard pipes are in says 50mm on it, but the previous owner said it was a 54mm he asked & paid for). Also has the air restrictors removed.

It doesn't do it all the time, and I did wonder if I picked up a dodgy tank of fuel. It has done it on 3 seperate occasions now though. I also think it is running rich as last week in the hot weather on overrun or very slight throttle off it would pop & bang like a goodun (the french villagers loved me ! :D ).

Hopefully a new set of plugs and the pc will fix it, but just thought I'd ask.

Cheers,
John.

The 998 uses the Weber-Marelli IAW 5.9M ECU, a 32-bit processor about the size a stapler that no longer uses a replaceable EPROM chip. Unlike the 996's 1.6M computer it (presumably) is designed to fire twin injectors sequentially.

Interesting that Shazaam. It looks the same as the ecu on my ST4S (2 big square connectors and mounted down by the battery).

I was told you can't chip these, and the DP kit for the ST came with a complete new ecu rather than a chip too, as did the 998 as the standard ecu is in the box with the standard pipes.
So does that mean the 998 shouldn't suffer the problems you mentioned due to short duration injector firing ?
Interestingly I'm sure the details for the pc say to unplug one pair of the injectors.

Sorry, this is starting to head off topic.

You can't do anything with that ECU, it is mapped according to the pipes I guess, but every bike is different, I think my 54mm ECU was labelled 996R54 or such like...

I doubt there's much you can do yourself, the obvious answer would be a PCIII and get it set-up correctly, but that's not cheap.