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I'm posting this up for a friend, I gathered information that I thought was necessary, but if you need more info I can get it.

Specs on the bike;
2007 100 C.I. Revtech engine
Chain
Air Cooled
5 Speed (unknown tansmission)
Oil currently used; 20-50 (Unknown brand)

Here's the story. We both live in Western Washington. Very rarely does it get above 85 Degrees in the summer. The time he was riding, it was overcast and mid 70's. Got caught in slight traffic. Traffic was moving but at a slow pace. 20 minutes later, he noticed his oil pressure drop from 25 to 5.

He left the bike, grabbed his truck and loaded it up taking it back home (about 30-45 minute duration). When in the garage, he removed the oil cap and he could see the oil was bubbling inside.

Called up Harley, and all they said was the bike got too hot and he was in traffic for too long. Im not an expert mechanic or anything, but I would think that any motorcycle should be able to handle being in traffic for 20 minutes in 75 Degree weather. You guys have any suggestions or has this happened to you?

Thanks
 

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Sounds like the curse of the air cooled engine. No air passing over the cooling fins = over heated engine. 20 minutes of running with no cooling is pretty long.
 

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Don't go too far in that "should have" direction. I got caught in a construction zone for about an hour on my HD Road Glide when I was trying to cross the Mississippi at St Louis. Since the road was downhill for me I shut off the engine after maybe 3 minutes. I sat in that general area for the better part of an hour and just let up on my brakes to move forward a few feet at a time as traffic demanded it. My way of looking at it is that no way could HD have anticipated my situation so I had better cope with it. When the traffic started moving, I started my bike and proceeded to move forward. I never did see any overheating at that time. There are things like construction zones that are completely outside the area that bikes are designed to deal with. Unless we riders take responsibility for them, nothing will ever be good enough.
 

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"The time he was riding, it was overcast and mid 70's. Got caught in slight traffic. Traffic was moving but at a slow pace. 20 minutes later, he noticed his oil pressure drop from 25 to 5.

He left the bike, grabbed his truck and loaded it up taking it back home (about 30-45 minute duration). When in the garage, he removed the oil cap and he could see the oil was bubbling inside."

If you're not familiar with Evo's in general, and Revtech's in particular, an oil pressure gauge can be a frightening thing to put on your bike. They look very cool and race-ready, but they're about useless and can scare the pants off you if you're not familiar with that engine. Evo's always have enough oil, and it seldom has much pressure. On a hot 90+ degree day here in central Florida when I'm stuck in traffic, the oil pressure gauge will usually drop down to less then 5 psi. Flat line. (But the gauge itself looks pretty wicked!) An oil temperature gauge is actually useful though.

The bubbles he saw were likely from the air in the system working it's way to the surface in the oil bag. His oil wasn't boiling. I've never timed how long it took to flatten out, but bubbles in the oil as the bike cooled down are normal.
 

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...an oil pressure gauge can be a frightening thing to put on your bike. They look very cool and race-ready, but they're about useless and can scare the pants off you if you're not familiar with that engine.

Yup. Good way to scare the heck out of yourself!
 

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"The time he was riding, it was overcast and mid 70's. Got caught in slight traffic. Traffic was moving but at a slow pace. 20 minutes later, he noticed his oil pressure drop from 25 to 5.

He left the bike, grabbed his truck and loaded it up taking it back home (about 30-45 minute duration). When in the garage, he removed the oil cap and he could see the oil was bubbling inside."

If you're not familiar with Evo's in general, and Revtech's in particular, an oil pressure gauge can be a frightening thing to put on your bike. They look very cool and race-ready, but they're about useless and can scare the pants off you if you're not familiar with that engine. Evo's always have enough oil, and it seldom has much pressure. On a hot 90+ degree day here in central Florida when I'm stuck in traffic, the oil pressure gauge will usually drop down to less then 5 psi. Flat line. (But the gauge itself looks pretty wicked!) An oil temperature gauge is actually useful though.

The bubbles he saw were likely from the air in the system working it's way to the surface in the oil bag. His oil wasn't boiling. I've never timed how long it took to flatten out, but bubbles in the oil as the bike cooled down are normal.
Good post, Eye. A dry sump system pulls a vacuum as it scavenges oil and air out of the crankcase. That accounts for the bubbles in the oil reservoir.

I read that the boiling point of motor oil is about 300° C (or 572° F) !! That's as hot as a BBQ grill! Nobody could ride a bike that gets that hot!

When he called Harley they should of told him to throw a steak on it!! :coffeescreen:
 

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I was an HD EVO custom engine builder in California and won a big DYNO shoot out in Southern CA in 1994, with my FLHS, 96 inch Monster streetbike.

I have never seen or heard of an overheating problem with the "older" HD engine although, my bike had a large front mounted oil cooler that kept the oil at least 25 degrees cooler at all times than my Bud's HD's. I would pull the oil temperature dip stick out of my oil tank, show them the temp and then stick it in there bike and they would see the temp really shoot up. After that, most had HD touring coolers installed.

As stated earlier, the 'frothing' and bubbles in the oil is normal as is the low oil pressure at idle.

I do shut my engines down if the traffic is stopped, even on my new Goldwing, if it is really backed up and at a standstill. I also never leave the bike in gear with the clutch pulled in for over a few seconds at a standstill as this can really heat up the oil because of the friction between the drive and driven clutch plates.

Sam:)
 
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