How hot is too hot for a 1979 GS850

[Guest]

Dear All,
I am on the final stint of rebuilding my trusty old Gs850 from 1979, and we are down to carb tuning. That is not an easy task, as I have outfitted the bike with a 4 in 1 exhaust and pod filters (Yes I know ).
At the moment I am taking small 10 min rides, rejetting based on previous rides learnings, and riding out again.
After the first 10 min ride, and after standing still with the engine shut off for another 5 minuttes, I noticed that the engine was very hot. The headers were cold to the touch, but the engine block it self was untouchable. I took a reading with my barbecue thermometer and it read 103 degrees Celcius / 220 degrees Fahrenheit.

Is that fine or am I in trouble?

[Nessism]

Sounds normal. There is a lot of steel and aluminum in that engine which will retain a lot of heat.
Where the bike is most at risk of overheating is if you allow it to run while stationary for a long time with no airflow. Us a fan in front of the engine when carb syncing and such for example.

[salty_monk]

When they get too hot the idle speed starts to wander... that’s about the only sign.

[Grimly]

When they get too hot the idle speed starts to wander... that’s about the only sign.

They get a bit grumbly, too. And clanky, did I mention clanky?

[salty_monk]

When do you get weather in Ireland to be able to get it that hot...???

[erki52]

When they import it from England !

[Grimly]

When do you get weather in Ireland to be able to get it that hot...???

Not often here, but these bikes spent a lot of time stuck in London traffic for hours on end, on some of the hottest days of the years involved, so I know how uncomfortably hot they can get, even if not in Arizona, for example.
Having said that, the fitment of a more reliable oil temp gauge has alerted me to some hotter than desirable temperatures with the fairing on, and last year's purchase of an oil cooler to address this very thing has prompted me to look closer at the fitment of same.
The XJ came with a factory fitted oil cooler and I've never had cause to suspect that it's running a bit hot at any time.

[chris]

Dear All,
I am on the final stint of rebuilding my trusty old Gs850 from 1979, and we are down to carb tuning. That is not an easy task, as I have outfitted the bike with a 4 in 1 exhaust and pod filters (Yes I know ).
At the moment I am taking small 10 min rides, rejetting based on previous rides learnings, and riding out again.
After the first 10 min ride, and after standing still with the engine shut off for another 5 minuttes, I noticed that the engine was very hot. The headers were cold to the touch, but the engine block it self was untouchable. I took a reading with my barbecue thermometer and it read 103 degrees Celcius / 220 degrees Fahrenheit.

Is that fine or am I in trouble?

To me 103 C does seem a little high considering your thermometer may not of been completely submerged in the oil. My 831100 never reads more than 85 c on the digital gauge, but I do live in Canada . I am concerned that you might be running too lean. Have you checked the plugs ? Hopefully not white.

[Wingsconsin]

Not scientific - nor a best practice use of the laser temp gauge - but perhaps useful...?

<strong>