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Big Bore Stroker 325

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On 3/1/2018 at 1:57 PM, KLeptoLee said:

I will keep you posted on the tuning aspect.

 

Mybe you could make a video of the Dyno tune ....  :thumbsup:  

 

 

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Got it running Friday night. Finished up putting it back together and started tuning.
What I’ve noticed is on the 2&3 green fuel it’s lean between 14.9-15.6 as soon as it flips to 4 it’s back to 13.2.
Only got to put about 8 miles on it this afternoon. Hopefully the wind will calm down so I can cruise and tune.

IMG_6689.JPG
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great news that its back together and running, never had a bike with a chrome/ nikasil or what ever bore, so dont no how much running in it takes ? (i,m still back in the stone age with cast iron, but if done right it only takes 5 miles or so in stages with 2 or 3 complete cool downs and start again) what can the fuel mix meter go down to ? still cant see how it helps with performance ? can feel, experiment,  and years of practice be put in a program for a computer ? and what ignition timing do you have ?

stew

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2 hours ago, stew79 said:

 still cant see how it helps with performance ? can feel, experiment,  and years of practice be put in a program for a computer ?

On FI engines it is analogous to changing jets and adjusting needles in a carb.

And a wide band O2 sensor can tell you many things, with more accuracy, than seat-of-the-pants.

This from a 50 year rider, who is slowly but surely being dragged into the modern world of FI

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hi from england, i have looked into and read about efi for many years, but never had anything with it (apart from mercedes sprinter van, but thats common rail diesel and not likely to ever be tuned up) i would have thought ex gas temperature would be more useful in trying to get the maximum performance from a tuned up engine ? 02 measure is not going to help there, unless it can work at really rich mixtures, but that only works with the right timing. why go for max economy ? its not meant to save the planet, its meant to have fun riding on it. but for road use you could keep below what the max out put could be, to allow a safety margin. but you would perhaps need to see how far you could push the engine to no what its capable of.

stew

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Got it running Friday night. Finished up putting it back together and started tuning.
What I’ve noticed is on the 2&3 green fuel it’s lean between 14.9-15.6 as soon as it flips to 4 it’s back to 13.2.
Only got to put about 8 miles on it this afternoon. Hopefully the wind will calm down so I can cruise and tune.
IMG_6689.thumb.JPG.57af73f6be314d6fee31bf525e565279.JPG


It seems that’s it’s only Lean when in 4,5 or 6 gear then the 2&3 are a little lean 14.9-15.6
It must load different in a higher gear.
1st-3rd it 13.2 ish. I think there is enough fueling in the controller with the 305 big Bore reflash
I did try the cbr250 ecu, it would run right with the cold start enrichment. It was around 10.0 Rich.


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how much re programing can yo do to the original map ? can you "plug it in" to a pc to look at all the parameters ? some bikes no what gear you are in and adjust the power available to "protect the rider" but not on a 250 ? without enough experience in knowing what you need to adjust, and at what throttle position, rpm, load etc you could spend years fiddling about with this and get no where !   

stew

ps if you put a mukuni carb on it i could give you good jetting suggestions (but you would still need to no what the ig timing is doing)

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how much re programing can yo do to the original map ? can you "plug it in" to a pc to look at all the parameters ? some bikes no what gear you are in and adjust the power available to "protect the rider" but not on a 250 ? without enough experience in knowing what you need to adjust, and at what throttle position, rpm, load etc you could spend years fiddling about with this and get no where !   
stew
ps if you put a mukuni carb on it i could give you good jetting suggestions (but you would still need to no what the ig timing is doing)


I did send the Ejk in for a reflash. I can’t plug in and see the map. I don’t know it the 250 knows what gear it’s in.? After talking to my tuning friend last evening he said not to really worry about it at such a low rpm and throttle position especially if it’s not pinging. If it was higher in the rpms we would have a problem. Thanks For the carb offer but I have fully embraced fuel injection. I actually had to turn fuel down on the controller it was set to the B&B 305 set points. I feel it has to do with the longer stroke needs less on the controller.

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i suppose if the efi could be perfectly mapped it would  possibly make the same power as with a good carb, but with better mpg, less emissions. etc. if you get it on a dyno, perhaps 35 bhp would be a safe figure to aim for, but with more bottom end and mid range pull than a std 250. my 330 would wheely at will off the throttle in second at about 30 (only 5 gears, geared for 90 mph) but just ping the clutch in 3rd or 4th at speed and it was a wheely monster. (with very basic 1970,s tech)

stew

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Getting it dialed in. Thanks to Dustin and Dillon @ Dobeck.
Still working on the tune got most of the lean spots tuned out, got a rich spot or two to work around yet but it’s getting close. I almost have 75 street miles on it. I’m rather happy with it. Still trying to get used to the upgraded clutch.

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The compression ended up being a little higher than what was originally figured. It’s 14.9:1 I called cometic gaskets they can make me a gasket up to .120. A .060 MLS head gasket will bring it down to 12.5:1

 

 

It doesn’t detonate or ping. But going to lessen it to be on the safer side.

 

Combustion chamber cc’s 20

 

 

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10 hours ago, Kompact said:

How's the bike running?

Raced it today. Bike ran great, and I realized I’m not as young as I once was. 

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Right on, must have been fun. How'd it go for you?

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2 hours ago, Kompact said:

Right on, must have been fun. How'd it go for you?

The bike preformed well, it had plenty of power for today’s event. The course was nothing but mud since it rained heavily for the last 5 days. I weighed the bike last night with a full tank of fuel no turn signals or mirrors it weighed in at 330lbs. It gained a lot of weight with the new tires and ultra heavy duty tubes. 

So how did it go? 

I worked my self up so much 30 minutes into it I had to pull over and puke. Besides that I had fun. 

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great post for parts reference!    

 

Just re-use the original crank bearings?

 

This may be my next summer mod after my warranty expires.

 

 

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