Bimota Forum

SB8R Tuner · Joined: 29 Nov 2010 Posts: 86

SB8K owners, I am repairing a couple of SB8K ecu's and noticed when I rev the motor up, while in neutral, the MPH readout displays random numbers. Is this a comon problem on these bikes?

zombie · Joined: 10 Feb 2009 Posts: 272 Location: UK

not on mine, but the speedo sensor is always misbehaving must be very sensitive ???

vort28 · Joined: 22 Mar 2010 Posts: 2194 Location: Northwest , UK

No, can't recall mine having that issue either, and my speedo seems quite steady also.

SB8R Tuner · Joined: 29 Nov 2010 Posts: 86

Thanks for the reply's guys. I talked to daotoys1 the other day and he is going to check if his is doing anything strange. It's really strange, sometimes it does it, sometime it don't. Are you guys happy with the way your SB8K's run? Did any of you happen to get the data acquisition software when you purchased your bikes?

vort28 · Joined: 22 Mar 2010 Posts: 2194 Location: Northwest , UK

Mine runs rich but other than that seems ok.
Bought it from bloke that used to run Bimota racing. He had a few Santamonica's and also had software. But one copy only and was unwilling to sell.

daotoys1 · Joined: 29 Feb 2008 Posts: 202

My BIMOTA SB8K Santa Monica #8 bike does not seem to have this anomaly .

I had 3 BIMOTA SB8RS bikes ( #5, #6 and #10 of 150 ). All 3 of these bikes which had the fabulous Suzuki TLR engine did have this "problem".

The SB8R / SB8RS of course used different instruments than the SB8K Santa Monica. And the intake, ECU and other components are different.

These bikes do share the same engine.

I remember talking at length about this strange happenings with both Bob Smith ( USA Importer of BIMOTA ), and Ken Zeller ( world class tuner ). I remember that the use of different spark plugs would change this. The use of resister spark plus would minimize and in some cases eliminate this, while using regular spark plugs ( without resister ) would allow and or amplify this .

I think that it has to be related to EMF overflow from the engine and or ignition having an effect on the digital instruments.

Is this "problem" really a problem, or is it simply an oddity ?

Will having this problem in any way cause damage to the bikes electronics ?

If it does not harm anything then it is not so bad a problem, but if it can lead to damage then it is something to investigate as well as something to fix on these bikes.

The one thing that seems to be the case is that some bikes seem to do this and some dont seem to do this, or they do it at times and not at other times.

DAO

SB8R Tuner · Joined: 29 Nov 2010 Posts: 86

Thanks for checking daotoys1!

vort28 · Joined: 22 Mar 2010 Posts: 2194 Location: Northwest , UK

When I bought mine there was another 8K for sale in Italy cheap, had running issues above 8 thou apparently buts thats all I know. I spoke to a few people about the bike and even the chap at bimota racing knew about the bike and said it was something to do with the pegaso ecu . I seem to remember he had tried to fix it with his software but couldn't . I think he mentioned about 1500 euro's for a new unit.
Mine does seem to eat plugs, don't know why, they just stop working.

zombie · Joined: 10 Feb 2009 Posts: 272 Location: UK

My 2cents is that these bikes are very sensitive to TPS set up. Rightly or wrongly I use the TPS adjustment to dial in more or less fuel.

I backed my TPS back to very lean to start with but after a while made it a little richer and got a few extra HP out of the bike and a super smooth throttle action.

The danger is at a richer TPS setting a few misfires e.g. on a very long wet run up the motorway (as I had recently), you lose a cylinder and then you have to stop and replace the spark plug because they get sooted up and stop firing at all after a while. Running on one cylinder can have truly disastrous consequences as I found when my exhaust system went up in flames during an attempt to get the bike home.

The other thing is that to me the water temp sensor is way too high next to the pressure release valve on the radiator so they tend to take ages to warm up and this probably affects the fuelling.

SB8R Tuner · Joined: 29 Nov 2010 Posts: 86

Now I have repaired these ecu's, I'm in the process of reverse engineering the code so I can make changes to the fuel and spark tables. If a bike is setup properly it should never eat plugs like that. Playing around with the TPS is just a band-aid and has never gotten good results. I know my SB8R didn't run like it should, until I got the factory ecu software and reprogrammed the ecu. Now it runs like it should.