So, the other day I had the misfortune of getting caught in absolutely horrendous downtown Atlanta gridlock for far too long.

The temp gauge slowly crept up to the top end of the white zone after about 15 minutes and I started turning the engine off whenever stopped (leaving the radiator fan on). A few more minutes of this and the temp gauge was just past the white zone but not touching the red line yet. The engine didn't seem to be running rough at this point. I was finally able to temporarily escape via a steep uphill side-street but as I started climbing the engine hesitated and stalled. At this point I just put the sidestand down and waited. I think I smelled a bit of coolant and could feel the overflow tank gurgling.

After about 7 or 8 minutes I started the bike back up, which was harder to start than normal. The temp had moved back down a bit. I let it idle for about 20 seconds then gave it a few small revs and it seemed alright, but when I pulled away the engine stumbled and wasn't pulling very well below 3k rpm. I finally got moving and the engine had a chance to cool down to more normal temps. It idled smoothly but still seemed to have trouble when pulling in 1st below about 3k rpm unless I really feathered the clutch. Above 3k and it seemed to run the same as before. Gingerly rode her home and she seemed to run better, but not quite normal.

The next day she starts up just as easily as before, smooth idle, no weird noises. Let the engine warm up until the choke is off and gently pull out in first gear, but the engine hesitates a bit and doesn't pull as hard at low rpms as I remember; almost feels like a flat spot at around 2.7k rpm that I don't remember having before. As the bike fully warms up it seems to run better, but it still doesn't feel quite the same, but maybe I'm just imagining things now that I'm worried about the bike.

Do you think I did lasting damage to the engine? I've never overheated an engine before, so I don't know what to look for. Once it's warmed up it's hard to tell if there is a difference in power or if my mind is just playing tricks on me. I'll be changing the oil before I go out again since it's almost due anyway, is there anything else I should check or do?

Thanks for reading this. Hope you guys think I'm just stressing over nothing.

btw, it's a stock '88 with 34k miles.

 

If she's been that hot there may have been some fuel evaporation from the carbs to explain the rough idle , it stalling up the hill and difficult starting .

I live in the UK so we don't get those extreme temperatures you get in Atlanta , though I wouldn't have thought you'd have hit peak temps' just yet

The danger with over-heating is you'll warp the cylinder head , if she starts to overheat in normal conditions , that may have happened.

I think a compression test , may give you a better idea of any damage that's been done.

 

These are tough old girls. I boiled mine almost dry after the fan switch failed. The oil cooled had just enough cooling power to stop her from seizing. When I got home she took 2 1/2 litres of coolant. These bikes only hold 3 litres & from memory 300 ml's is in the overflow tank. I've been riding for two years since so hopefully as Hawkwind said the issue was vaporisation. Time will tell if you have damaged anything. Give your bike a little time to settle & hopefully all will be well.

 

long as you don't have coolant in your oil it should be okay, could foul a spark plug from getting too hot possibly. I learned years ago to shut it off before it gets hot enough to boil the coolant and spit it on the ground.

 

Thanks for the replies, guys. I'll check the plugs, change the oil, and top off the coolant after work today.

 

Check the 3 way plastic hose connector below the radiator filler - when the bikes get too hot that connector is inclined to fail...........

 

Sparks plugs were indeed a bit fouled. Changed them along with the oil and she's back to pulling like a freight train. Cooling system looks like it's in good shape, too.

 

Good deal, man. Tough old girls....

 

These bikes sure dont like all that stand still in the heat. i have had to turn mine off in a grid lock too.
I dont know how long you have owned your bike, but you may want to consider a coolant change if it hasnt been done in a while. not that it will save you from overheating, but these cooling systems need all the help they can get.