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FI system programed too lean - from Feedback forum

1753 Views 11 Replies 8 Participants Last post by  billmeek
NebraskaKen said:
I've recently purchased a 2005 Burgman 400 and it has a very lean condition at idle and at 3,000 RPM under a light throttle. The dealer has been in contact with Suzuki, but no solutions seem to be available.

I was hoping that the FI system would be all but trouble free, but now I'm longing for the good old days of adjustable carbs.

I've been on other Burgman forums, and this is not an isolated complaint.
First, welcome to the BurgmanUSA forums Ken. Glad to have you join us.

What grade of fuel are you running Ken? Paul mentioned before that 89 grade fuel in Nebraska, although cheaper, has a fairly high percentage of grain alcohol in it. Have you tried draining the fuel and replacing it? What are the exact symptoms you are seeing? I'd also be interested in reading up on the issue on the other forums. Mind pointing me in the right direction?
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You should double check for air/vacuum leaks and use the recommended fuel. The stte of tune of these engines makes them relatively impervious to fuel octane levels. The more likely cause is a problem in the induction system/tract.
Until a Power Commander or some thing like it becomes available we have no way to tune the fuel injection. Not much you can do.

What fuel grade is everyone using for the B 400?
Regular grade fuel is what I use in the 400.
Anything more than 87 RON octane is not only a waste of money, but slightly degrades performance. Higher octane fuels are formulated to burn at a slower rate and contain slightly less energy per unit volume. Higher octane fuels also have a somewhat shorter shelf life and will degrade more quickly when left unused, as in over the winter, compared to low octane.
Fuel Injection

I don't know about the 400 and how the fuel injection is set up compared to the 650 but if it is like the 650 it will have a IAT sensor and if it does you can cut a resistor into the dark green wire. I used a 680 ohm 1/2 watt from Radio Shack. What this does is fool the brain into thinking the air temp is colder than it is there by richening the fuel mixture. It worked on my 650 and did not efect milage.
Thanks Docta for the info. I will use 87 for the tank. When I had the Savage I noticed that if I used 89 I did not get blueing in the exhaust tank nor did it backfire as much. Could be my imagination but when I saw the other Savages with low miles they had a tremendous amt of oxidation on their exhausts compared to mine.

If I recall, the Savage was carbuerated. The Newer Suzukis have Fuel Injection, which is programmed to run just fine on 87 octane.
680 ohms in series with the IAT, now that's a Magyverism who's time has come.

I don't have any lean running problems with my 400. What's everyone talking about?
It makes sense though, to have a lean mixture at idle.
The combustion chamber, pcv valve, exhaust, valves and spark plug will be cleaner.

Who's going to be first to take their potted CVT controller apart after they dump the memory and check for an erase window or flash pgm pin?
Not me.
Could it posibbly be that Ken's scoot is just experiencing new belt break-in? I rememberwhen mine was new that it seemed to lurch and jerk at slower speeds for a few hundred miles until things got settled in.
It's sorta hard to tell since he made the one post and didn't provide any followup infomation. :?
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