Question & Answers

Red vs. Green

Q: Will there be a problem if I use extended-life antifreeze (non-green) in my bike? Are there any contraindications for using such? Five-year interval versus two-year is a plus. Jim L.Via e-mail

A: Replacing the traditional ethylene glycol antifreeze with a propylene (synthetic) based coolant makes a lot of sense. The new stuff is less toxic, a real factor if you have small children or pets, and has an extended change interval. However, the extended life cycle doesn't mean you can just pour it into your radiator and forget about it. All coolants degrade over time. At least twice a year you should test the coolant's freezing point, and since you plan on leaving the stuff in there for an extended period, I'd also recommend purchasing a coolant test kit, such as the Fleetguard CC 2602, available anywhere heavy truck or construction equipment parts are sold, so you can test the antifreeze for contaminants on a periodic basis.

Big-Twin BlowBy

Q: For my 65th birthday, I purchased a new 2001 carbureted FLHR. It's stock with the exception of a Stage One kit, dynojet, high-flow air cleaner and Bartel slip-ons, all of which were installed at 5000 miles. It was broken in exactly as the H-D manual recommended. I have had all the required H-D maintenances at the H-D dealer at which I purchased it, and am very satisfied with them. At around 18K miles I started noticing oil blowby out of the air cleaner and down the right side. The dealer drilled out the backing plate and rerouted the breather hoses at 26.5K miles, which took care of the problem completely.

I now have 42K on the clock. Oil consumption has been slowly and steadily increasing (and I have to assume it will continue to do so) and it now uses one quart every 2500 miles or less. This is 20W50 H-D oil. At my age, this will probably be my last motorcycle, so I want it to remain in good mechanical condition. I'm not going to go broke buying oil for it, but I want it to be efficient.

1. Is this oil consumption excessive?

2. Is it in any way related to the previous blowby problem, of which externally there is now zero evidence?

3. Is it possible the blowby fix merely covered up the problem and the engine is using oil internally? I notice no smoke out of the exhausts.

I have mentioned this to my H-D dealer and haven't quite gotten a -*definitive answer. At the 40K service, they ran a compression test, and both cylinders checked out at 160 psi. Spark plugs look normal. If the rings or cylinders were worn out, how could the compression be that good?Jay TuttleVia e-mail

A: The short confusing answers to your questions are sort of, maybe and probably. While I wouldn't consider a quart in 2500 miles excessive, it does indicate that some oil is being used. Normally, I don't get too worried until an engine starts to burn a quart in 1000 miles, so if the bike was mine I'd be watching it, but I wouldn't be overly concerned-yet. The answer to your second question is a bit more involved. When blowby occurs on an FLHR (or any other engine using a crankcase vent routed into the air filter), oil makes its way through the engine breather into the air cleaner. The oil is then pulled into the engine along with the fresh intake charge and burnt. Unfortunately, the oil tends to carbon up the rings and glaze the cylinder walls, resulting in a less-than-perfect top-end seal. Once this occurs the die is cast. The poor top-end seal leads to more blowby, which pushes even more oil into the air filter, which is then forced into the engine, creating more blowby and so on. Did this cause your problem? I honestly can't say, and with 42K on the engine some top-end wear is inevitable, but it certainly doesn't help. The problem from a diagnostic standpoint is that in this case, a compression test really doesn't tell you much. It only tells you that the compression rings are holding compression at cranking speeds. In fact, a little extra oil will only help them hold compression. Meanwhile, the oil ring could be shot or even missing entirely. The compression test would never show the difference. My educated guess is that your top end is wearing out. Chances are it will get worse over time. My suggestion is to monitor it carefully for the time being and repair it at your convenience.

Got a question? Need an answer? Reach Mark at Zimmemr@aol.com