Honda Spree and Elite 50 Forums

Before all the laughs begin, let me just say I already have a wideband o2 sensor on my crx drag car. I'm planning to weld an o2 bung onto my pg long to get the carb dialed in really well.

I'm afraid that i'm going to screw up my BBK, and I don't feel like blowing $200 on that.

So, has anybody else done this? I know it needs to be installed between 10 and 2 oclock on the exhaust pipe to avoid condensation build up. I was thinking of putting it on the green dot on the below picture, because by the blue dot the exhaust isn't as wide, I don't know if the o2 sensor protruding into the exhaust path at that point is going to screw up the flow.

I heard that it was possible for the exhaust to suck in air from the tailpipe? Is that true? I wanted to avoid the end of the exhaust pipe for this reason. Even the innovate motorsports install documents say that on single cylinder engines the oscillations of the exhaust gas are so large that a lot of outside air enters the exhaust from the exhaust tip....?

At the tip yes. In more not so much if not at all. the problem you will run into is the o2 sensor pluging up with soot and oil. If you can use a tail pipe bung you can take out to clean for initial tuning the better. A tail pipe bung like the one used on dynos.

I was only planning to use it for tuning purposes and after getting it where I want it, uninstalling it, and then plugging the bung for normal riding.

wideband is over kill for a street machine you should be able to get it close with plug chops cht and just the feel... maybe a egt probe would help you but idk... wheelman has built a * of a reliable bike using only the skills he has learned from blowing up a bore or two cht gauge and plug chops....

No better way to tune than with a wide band.

I know you think it's overkill, but I already have a wideband and though wheelman is awesome, I'm slightly scared that even he blew up his first BBK, and it wasn't as expensive as these Polini corsa bores. I'm being overly cautious to protect my $230 BBK investment.

I'm going to try and post a thorough account of how the wideband tuning goes on a 2 stroke because there isn't a ton of info. A lot of people saying it won't work or I'll burn the sensor up but not a lot of real world first person info that they have tried it themselves.

Mostly its just opinions and assumptions, I like to know for myself, might as well try it out.

Wideband O2 sensors from koso for 2 strokes have a screen meshing around the sensor probe, at least the one I was looking at from Koso did. Maybe you can do that as well.

I've found a few suggestions even from other wideband companies saying to put the o2 at the 12 o'clock position to have the least amount of oil contamination. And to recess the o2 more than standard.

why worry a bout seize the bore. just start bigger jetting..

Interesting. Ive never heard of this on a 2 stroke. Im curious to see how it goes. Imho tuning via plug chop and cht is still the easiest way to get a accurate tune

Easiest way to accurately tune any single cylinder carb or efi throughout the entire rpm band is with an EGT and a CHT combined with a tach, regardless of how many strokes. Sometimes by the time you do a plug chop its too late, EGT is instant read of what the engine is doing at all rpms not just WOT. Try to use an analog gauge, alot faster for you to read, unless you are data logging of course, but you can still use the analog gauge and just run wires to the black box connector.
EGTs are cheap and can be removed after tuning is complete and also swapped onto other engines, a plug chop destroys your plug and costs money every time. Not discounting the old methods at all, but getting it done right the first time rather than trial and error and waste is a benefit to everyones pocket book.

LoveMyHonda wrote:......................................a plug chop destroys your plug and costs money every time. Not discounting the old methods at all, but getting it done right the first time rather than trial and error and waste is a benefit to everyones pocket book.

You do NOT have to destroy the plug to read it. The proper tool makes it quick and easy to read the plug.

http://www.ebay.com/itm/230599783076?ss ... 1438.l2649

LoveMyHonda wrote:\ a plug chop destroys your plug and costs money every time

How does it destroy the plug??? and a 2$ plug is alot cheaper then 100 + dollars for a wideband 02 sensor lol

he is talking about cutting off the threads im guessing. Like bear said there are ways to look down there and see what your jetting is doing..
people are looking at the wrong place when checking a plug.