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Mapping Couplers

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Hi all,

First post here, long time reader what a useful forum.

I have recently got back into MX after about 20 years, last bike I owned was a yz50, last bike i rode was a KX125 (maybe a 98?). I've always loved Suzukis though so have started off with an RMZ250 2010 first of the EFI's. 

Four strokes are new to me let alone EFI. The bike has an S7 exhaust and came with the rich map coupler plugged in but no others.

On a typical day, I'll ride the first 20 minute practice session and the bike will run nice. 10 - 15 minutes in I have to stop because of arm pump and I sit in the start area and let the bike idle. 

After a couple of minutes rest I go back out and the bike starts to miss a beat here and there at high revs. This might happen for half a lap

The next session out the bike starts fine and idles fine but when revving takes about 3 - 5 revs to clear what feels like backfires. Then I'm back to square one - seems to ride fine for 15 - 20 minutes.

I've changed the plug which did help a lot to minimise these little nags as the old one was black AF but not oily thankfully although it hasn't eliminated them.

I understand the S7 might require rejetting a carb but since this is EFI could that be why it came with the rich map? I tried taking the map off for one session as my understanding is that without anything plugged in it's standard so not rich and not lean. All this resulted in was that it felt like it ran just the same but wouldn't idle and cut out twice round the track when I pulled in the clutch and let the revs drop to idle speeds. 

Any advice appreciated, all new to me this but trying to learn!

Thanks ?

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Good Morning friendo! So from what I remember you do need a coupler plugged in. When I did my training on the EFI systems at Suzuki if you do not have one plugged in it switches to a sort of "safe" mode which is close to standard tune. I run the lean coupler and the bike seems to enjoy it, although I have a 17 so maybe better injector? I would try to clean the fuel system, work off the old carbon with some seafoam and an italian tune up. try a freshy plug (I read you did that but try again maybe?) Other than that, getting your hands on the other two coupler would help. Have you played with the idle adjustment screw on the throttle body? Let me know how this works for you! I can look up the canandian prices on those couplers too, let me know if you want those! Hope I helped some!

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Hey Samsquanch. Thanks man, yeah she is a good looking bike but needs a few jobs doing. I just had steering bearings turn up yesterday as they're badly notched so that's next weeks job. I'd like to service the suspension and it has one bent rad. Maybe some white fork guards and a disc cover too ?

I've heard of seafoam but I don't think it's something we have in the UK off the shelf. Guess it's supposed to be better than your average engine flush? 

The info about the mapping plugs is definitely useful. I thought the standard one was just as dust cap as the manual only lists the two modifications. I will see if I can get hold of the other two as I wanted to at least see what they're like. Also no I've not messed around with the idle screw, might be a good idea to tweak if I'm going to try a leaner map, it's just the track I was at when I tried this doesn't allow bikes running in the pit so it was really a quick check and see job on the track. 

Thanks again mate ?

 

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Yeah the rubber seals the chamber since the electronics are sensitive to small changes, that's kinda how the system works, it knows what map depending on what amperage etc is flowing, or something along those lines. I'm not the best with that but that's how I understood it, either way they told me to make sure to have all three, and let the customer know when I deliver a bike that I tell them to keep track and not lose them. I guess the guy before you didn't have such luck, but I hope the beet for you man! I love my bike, also if you dont have a 51T sprocket on it I just put one on my bike and it woke it up a bit on the track! 

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Interesting, yeah I think I'm the third owner so no luck there. I will see if I can get hold of the couplers. Also thanks for the tip on the sprocket, it's plenty powerful enough for me right now but the more confident I get you know.. 

Thanks man, I appreciate the help ?

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