GS850...how concerned should I be of overheating it in traffic?

[Guest]

It was a pretty nice 70-something-degree day today, but traffic sucked.

So...what about in a few months when it's 100 degrees out? How much idle time is "too much" when it's hot out? Five minutes? Eternity? No (legal) lane splitting here in GA.

Just wondering how much of a concern overheating really is. Anyone here cooked one idling/creeping in city traffic?

[GSXR7ED]

As long as you change oil every 3500 miles, the engines are strong. Make sure she doesn't leak too much...and don't rev her...


Ed

[max parsons]

In Finley the temperature regularly reaches 40*C and for the first 20 years I've owned the Pig it was always thrashed in and around the redline to keep up with all the modern bikes.Now that I'm over 60 I will always give it a squirt but not often and not for long.The Pig has just clocked up 330,000ks.These motors are incredible.Just ride it like you stole it and KEEP UP THE MAINTENANCE.

[limeex2]

I lost the temper in my rings when stuck in traffic and I let it idle. I was also stupid enough to just sit there with the bike idling. I deserved it for being a f.d.a. My 2 cents worth.

[Chaz]

Yeah, it seems these have a great reputation for longevity/durability. Only have 22,000 miles on this one, so I'm hoping to get quite a few more out of it.

limeex2, how long did you sit idling and how hot was it out?

[limeex2]

90 plus. traffic was backed up for well over a half hr. it would move just enough to creep forward about a car length every couple minutes or just enough not to shut it off. Like I mentioned,not the bikes fault, but my laziness/stupidity.

[Grimly]

Yep, did exactly the same, on a 140Kmile engine when stuck in London traffic during a baking hot August afternoon. The bike got home ok, with no sign of trouble, except the usual fumes (it was needing a re-ringing by that point anyway), but the following morning it just wouldn't start. It would crank over like there was no compression - which there wasn't, to speak off. Stripped it and found the rings had all gone weak. Remarkably, for that amount of miles, a mic revealed there was no bore or piston wear, and all that was needed was another set of standard rings.
Since an accumulation of faults caused by the PO had reared their heads (knackered dogs on 2nd gear, trans to mid-drive oil seal, and some other things than needed a complete strip, I simply put in a spare engine that did for the next 100K, no problems.
I still have the new Std rings, the old good pistons, block, cams, crank etc, so I'll be using them on a good bottome end sometime soon to get the other GS850 together.

[Chaz]

Thanks for the input, guys. Nice to hear that it also didn't (at least seem to) ruin anything other than the rings. I'll be careful of traffic on hot days and make sure the charging system is working well so I can cut if off and on confidently if I do get stuck.

[Chaz]

Might also be a neat experiment to check the head temp under different conditions if I ever get one of those infrared thermometers...

[tkent02]

Thanks for the input, guys. Nice to hear that it also didn't (at least seem to) ruin anything other than the rings. I'll be careful of traffic on hot days and make sure the charging system is working well so I can cut if off and on confidently if I do get stuck.

Meh, if it's tuned well it will start in a fraction of a second when it's hot, not much of a drain on the charging system no matter how often you do it.

[Nessism]

An air cooled bike stuck in traffic is BAD. Sort of like leaving the bike sitting idle in the driveway for a long time. The header pipes turn blue (or red if running with the choke on). Rings losing temper make sense. Running synthetic oil may help a little, but nothing is going to save the rings.

[John Park]

An air cooled bike stuck in traffic is BAD. Sort of like leaving the bike sitting idle in the driveway for a long time. The header pipes turn blue (or red if running with the choke on). Rings losing temper make sense. Running synthetic oil may help a little, but nothing is going to save the rings.

Some designs can convection cool to an acceptable extent. A horizontal cylinder such as the Honda 90 or the current Honda Grom 125 can replace rising hot air with cool air from below. BMWs fare well. Even the GS twins do okay having generous finning and three sides exposed, but the center cylinders of a four are dependent upon forced flow as they're not only generating heat but being heated from both sides.

It doesn't take much airflow to cool these things; you just have to replace the air on the surface, and past a certain point - about 45 mph - increasing the airflow won't remove heat much faster. This makes a fan less air-cooled inline four an audacious design. It just needs to have a ten mph breeze. Doesn't take much but you need some.

[tkent02]

A little breeze, or a little common sense goes a long way. If you are worried shut it off until it's time to move.

[TxGSrider]

I know its a little different, but I have ridden lots of air cooled machines (atvs,go karts,mini bikes) and especially with the atvs (2 stroke and 4 stoke), we'd ride on 90 degree days barely moving (we ride in groups) and it never seemed to hurt them. Maybe being they are single cylinder that dissipate the heat more evenly or something?

[John Park]

I know its a little different, but I have ridden lots of air cooled machines (atvs,go karts,mini bikes) and especially with the atvs (2 stroke and 4 stoke), we'd ride on 90 degree days barely moving (we ride in groups) and it never seemed to hurt them. Maybe being they are single cylinder that dissipate the heat more evenly or something?

Exactly. Singles have inherently better airflow; a BMW twin is two singles from an airflow POV. The nikasil cylinder is another advantage that atv's are going to. Suzuki's SCEM is an example. Barely moving is a whole lot better than stopped. How hot it is doesn't matter so much because the air next to the metal gets hot fast even on a cool day. You can't get rid of the heat without getting rid of the air.