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So i just was wondering. Ive read here about upgrading the z with ninja 300 injector? Just wondering will it be a plug & play kind of upgrade? Also what are benefits from this. Sorry in advance if dumb question
 

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So i just was wondering. Ive read here about upgrading the z with ninja 300 injector? Just wondering will it be a plug & play kind of upgrade? Also what are benefits from this. Sorry in advance if dumb question
You don’t “jet” EFI bikes with injectors. If you do swap to the 300 injector, FOR SURE you need a self mapping tuner or dunk time to have any chance on getting it to run right. We tested quiet a bit, and the OE injector handles our 155 stroker just fine, so unless you’re doing a package larger, don’t bother....
 

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Agreed, I have the kit from mnthbx but I swapped to the 165 kit which brings it to 177 and I can't imagine using the 300 injector on anything smaller. Most of my map is pretty low. That said I wouldn't use the stock injector on anything above 165.
 

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I have the 143 kit, V2 head, bigger TB, ECT...the only spot I could see it having an advantage is way up in rpm's at the top of 4th. I've got my rev limiter set at 12,200 and passed about 9500, close to 10k rpms is really the only time it seems like I could use more fuel than it can deliver. But I'm rarely up that high in 4th for normal riding and commuting.

I tried the 300 injector and it's a pain in the *** to tune. I've got the pc5 and auto tune. Could get it to run awesome up till about 6k rpm's then it would run like ****. And i could get it to idle correctly for nuthin. It would slowly go down in rpm's till it shut itself off. So I slapped back in the stock injector, reloaded the map I previously built, and back to running like a beast
 

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Agreed, I have the kit from mnthbx but I swapped to the 165 kit which brings it to 177 and I can't imagine using the 300 injector on anything smaller. Most of my map is pretty low. That said I wouldn't use the stock injector on anything above 165.
Drop me a contact Mysta, I just updated to the 165 with Stroker = 177 as well. Had a couple of questions for you.
 

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Guys I have a 177 set up and need to upgrade the injector. What's the best choice the Ninja 300 injector?
 

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Well I ordered and installed the injector for the 2017 Ninja 300. Going to start tuning her this weekend I hope.
 

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Spent the weekend working on the tune. Lots of very high negative fuel numbers. As high as -50. At red line in 4th the numbers are only like +1 or +2. Wondering if the stock injector might be better? Not sure. She is running pretty darn well though. Not sure what’s better high neg numbers or high pos numbers?
 

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So I called Dino jet today and they said as long as your idle is ok your fine. They mentioned that sometimes with a huge injector you can get the idle low enough.
 

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Correct me if I'm wrong........ but it sounds like you are determining injector size by how it idles?

I somewhat frequently call "Dino" jet since I work with their "dino's" on a semi regular basis for about 19 years now. Under no circumstance has idle been a measure of how "ok you're fine". Pretty sure DynoJet would agree with me.

Looking forward to helping. We need more details please.
 

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Correct me if I'm wrong........ but it sounds like you are determining injector size by how it idles?

I somewhat frequently call "Dino" jet since I work with their "dino's" on a semi regular basis for about 19 years now. Under no circumstance has idle been a measure of how "ok you're fine". Pretty sure DynoJet would agree with me.

Looking forward to helping. We need more details please.
No I have a 177 kit and a lot of porting. In my fuel maps with the 300 injector I was running large negative numbers. It runs real good but I wanted to check with them to make sure it was OK. Dynojet said the only issue could be is if it didn’t idle properly because it injector so big. Mine idles fine so, I just wanna make sure I have the optimum size injector. When I ran the stock injector with This combination the stock injector had huge positive numbers and I felt it was better to try the 300 injector. Just did not want to run out of fuel on the top and red line
 

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The stock Z125 injector is rated at 105cc/min and a Ninja 300 injector is 200cc/min so you must adjust for an almost 100% increase in maximum fuel flowrate. Your larger engine likely requires a flowrate somewhere between those two figures. I'd expect to see high positive trims with a small injector as the controller is trying to keep it open longer but at some point it physically may not flow enough fuel (at reasonable duty cycles). The only option is to install an injector with a greater flow rate and then you might have to enter negative trims to limit the flow rate to match what the engine actually requires. The observed AFR at full throttle is what should dictate if the injector is too small or too big. The point brought up about idle quality is often heard when the low RPM flow of a big injector can't be properly adjusted down by the fuel controller. If it's idling & running well with safe AFRs then it sounds like your tuning is very close to what your bigger engine needs.
 

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The stock Z125 injector is rated at 105cc/min and a Ninja 300 injector is 200cc/min so you must adjust for an almost 100% increase in maximum fuel flowrate. Your larger engine likely requires a flowrate somewhere between those two figures. I'd expect to see high positive trims with a small injector as the controller is trying to keep it open longer but at some point it physically may not flow enough fuel (at reasonable duty cycles). The only option is to install an injector with a greater flow rate and then you might have to enter negative trims to limit the flow rate to match what the engine actually requires. The observed AFR at full throttle is what should dictate if the injector is too small or too big. The point brought up about idle quality is often heard when the low RPM flow of a big injector can't be properly adjusted down by the fuel controller. If it's idling & running well with safe AFRs then it sounds like your tuning is very close to what your bigger engine needs.
thank you for the reply. I do think I’m close to being right where I need to be. I‘m just not used to large negative numbers on my PCV’s. I have few on other bikes and they are all much more positive numbers. Right now I’m running 13.6 in the Low rpm cells say 1500 to 3000 then 13.2 in the higher. She pulls real good to 11k or so in the lower gears and lags a little in the higher but I guess that’s to be expected.
 

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Well. Every time I open my mouth to make a smartass remark I end up learning something and sticking my foot in it. My apologies @Somefun. That totally makes sense about how an injector might be too big to allow a proper low idle.
 

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I’m gonna bump it a bit richer to 13.1 in the 80% throttle opening and then try 13.0 or 12.9 for WOT
 
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