Exhaust valve stems are white!
 

I installed a Rinehart 2 into 1 system on my '08 Street Glide last Saturday and was surprised the exhaust valve stems had a white coating. I've been running the stock headers with SE slip-ons, SE AC and stage 1 download since new (about 7,000 miles).

Is this white coating an indication of too lean a mixture? Also, will the 2 into 1 make it run even leaner? I wasn't planning on adding the SERT right away, but I will if absolutely necessary. Thanks

I’m sure opinions will differ, but you cannot read the plugs (or in this case valve stems) with modern fuel injection like you could with the older carbureted engines. With carbureted models, white plugs meant you were running lean. With FI models, the fuel is constantly adjusted to maintain a slightly lean ~14.7 air-to-fuel ratio during normal riding conditions. This 14.7 A/F ratio insures complete combustion of the fuel to keep the EPA happy but leaves the plugs white. It’s nothing to worry about.

DA*N!!!! Thats pretty friigin white. If it we're a carbed bike, there's no well in L a mechanic(a real mechanic) would agree/stand behind a tune that was that lean. I believe I'd have to save sum cash and change that. JMO.

Are you getting any pinging? Had same issue on my 07 tried to blow the motor but couldnt.

The area that is white receives the most heat from the exhaust, if you look downstream behind the valve guide and guide boss you will see a nice black color. The heat from the exhaust is "heat scouring" the deposits off of the upstream side. This heat is one of the reasons that exhaust valves and guides usually fail first. As previously stated as long as the bike isn't pinging you should be all right. You could probably richen it up a little and see some performance gains though. Hope this helps.

I haven't noticed any pinging, but only rode about 20 miles since the install. I did notice less popping on deceleration than the stock headers/SE slip-ons though.

The ecu will adjust a little give it more miles then see what happens, try to get on the throttle real hard and listen, then pay attention at cruise speed.

For the record, going full throttle and listening for spark knock will not tell you anything about possible leanness under normal driving conditions.

Under high load/high throttle conditions the computer ignores the A/F sensor and sprays fuel at a rate indicated in preprogrammed tables set in the computer. This is called open loop operation. These tables are what the stage 1 download alters to cover the better flow from the AC and exhaust changes.

During normal driving the computer reads the A/F sensor and sprays fuel accordingly. This is called closed loop operation. The dealer download does not alter this part of the program to maintain EPA compliance. Keep in mind that in closed loop mode the computer constantly adjusts the A/F ratio. Adding the AC and exhaust changes requires no changes in closed loop mode. The motor runs the same A/F ratio as stock with slightly more flow (power).

The two conditions are exclusive of each other.

Thanks to all for the good info! By the way, performance with this 2 into 1 system is much better than expected as judged by my seat-of-the-pants DYNO.

I have a 07 road king and when I took off the head pipes I saw the same thing on my valves, your are not alone. I would like to see what the vales on a tune bike looks like. What sigma said makes sense you think that if you are in close lope that the ECM will adjust the afr to the factory setting base on the input form the 02 sensors no matter what the modifications to the air flow you make. In open lope it should matter because the ECM is not using the 02 sensor. Some people say that in close lope you will get a lean afr because of the air flow modifications. I could be wrong, but even with the narrow band 02 sensor the ECM should kept the afr to the 14.7 spec. that the EPA calls for. May be I do not unstained the operation of the narrow band sensors I tried a thunder max ECM for a little bit and that’s how it work but then again the thunder max uses a wide band 02 sensors.