170cc BBK update

[Natekidd222]

currently running a koso 170cc with a pcx150 injector and a kitaco midrange cam, efie set at 300mv, modified stock exhaust,Stock intake, high flow oil pump, oil cooler and wide band O2. I have about 300+ miles of WOT it’s still holding up. I also ran this with the stock cam for 300 mi as well.

 

[m in sc]

you running the wide band to monitor?

 

[Natekidd222]

Yes most fueling is in the 13.0-13.6 range it’s. Not ideal. Full throttle is the richest fueling. If I remove the snorkel the fueling doesn’t keep up. I’m considering running a larger injector. Or purchasing the FI - con controller

 

[m in sc]

x92 saab did the larger injector w the same issues youre seeing, and it worked well.

on the 143 i ran the large nk intake/238 cam/larger tb and an aftermarket exhaust and keeps up ok w the pcx injector at 25/27 on the eife. anything more id up the injector as well. On mine in in the high to mid 12s wot bursts. (for what its worth).

 

[Natekidd222]

What do you guys recommend for the next size up injector?

 

[m in sc]

he covers it well here. I don't plan on going any further with this on mine as i'll fall down the rabbit hole, bad.

6 (actually 5) Different Fuel Injectors tested with EFIE device on a 164cc BBK

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hondatrail125.com

 

[Natekidd222]

Also stock cam and sub par fuel and extended wot toasted my first 170cc piston. I added some additional ring gap run high octane no further issues.

 

[JPMcGraw]

I had the FI-con and id just skip it and keep the EFIE unless you really want to tinker. The EFIE power delivery compared to the takegawa base maps is much much smoother and the EFIE will self adjust a little.

I did have some situations where i was riding and it seemed like fueling cut out for a few cycles but haven't had that happen since installing the EFIE and didn't happen before so i assume that was the FI-cons fault.

 

[m in sc]

keep in mind the ecu takes 50 ish miles to learn, its def not right out of the gate.

 

[Natekidd222]

Well I had another failure. Under wot for an extender period of time I managed to kill my 2nd 170cc piston. The 2nd ring got stuck in the ring land causing oil to be pushed out the crank vent. The cylinder is still in good shape so I ordered another piston and a 170cc injector. I also added a kitaco type 2 cam and will go another heat range cooler on the spark plug. I have previously added a high flow oil pump and cooler with 20w50 I ran 91 with Vp octane booster. I’m thinking of doubling up on the base gasket to lower the compression the Koso kit is 11.5 to 1 most other kits are 11:1. Let me know ur thoughts.

 

[JPMcGraw]

I really don't want to jinx it but the 170cc injector seems to have fixed my issue. Ive done a few joy rides now around the same temp and humidity as my last two failures and i had no problems. I even rode it to work 14 miles one way @ 45-55mph, in the mid 70s in the morning and it was 88* on the way home with plenty of throttle to keep up with traffic. I don't have a wideband installed so i can't comment on AFR but it still smells like a gokart after the ECU has had a few tanks run though it and the exhaust note just sounds rich. I remember when i had the FI-Con and i was playing with the fueling. Lean exhaust sounded clearer than when it was rich (think a brass instrument vs a brass instrument with a hand in the bell). I assume that's from having more unburnt fuel in the exhaust making it thicker and better able to absorb the sound. Also when i touch test the head when riding its hot but not "stingy" hot like before.

Super sciency stuff

 

[Natekidd222]

It was a 40 mi wot commute that did it. Afr showed 13:1 ish most of the time. I do have a stock exhaust. With first cat removed and larger header. I’m considering removing the 2nd cat, and adding a 15t counter shaft to lower the rpm and keep heat down. Also going to wrap the exhaust.

 

[SneakyDingo]

Super sciency stuff

Just remember that whenever we talk about super sciency stuff, geologists lick rocks and report how it tastes. Touchy feel validation and verification honestly is meaningful in a lot of ways.

 

[CTExplorer]

It was a 40 mi wot commute that did it. Afr showed 13:1 ish most of the time. I do have a stock exhaust. With first cat removed and larger header. I’m considering removing the 2nd cat, and adding a 15t counter shaft to lower the rpm and keep heat down. Also going to wrap the exhaust.

Just throwing out there the increased load vs RPM with a 15t might cause it to run hotter. Hopefully someone more knowledgeable might chime in on this.

 

[Natekidd222]

Good point , I also got a temp gage so I’ll be doing some testing.

 

[m in sc]

glad you got it sorted. must have been maxing out the duty cycle w the old injector.