Is It True That Aftermarket Exaust On A Air Cooled Motorcycle Will Make The Bike Run Hot Under Hot Condition
November 23rd, 2009 | 
Author: I’ve heard if you put on aftermarket exaust on your air cooled bike while riding in hot conditions…..it will most likely to overheat. And the reason of that is that “the aftermarket exaust products squeeze MORE HORSEPOWER from your ENGINE…. they also generate a lot more heat. And what some of these products do is take away any over-heat safety margin.” Even though you re-jet …. are these statements true?
Posted in Motorcycle Safety | 
Tags: Aftermarket, Bike, Cooled, Exaust, Make, Motorcycle, That, True, Under, Will
i’m guess not, i don’t know as much about motorcycles, but I know plenty about modding air-cooled cars. (owner of a 1987 Porsche 911, as well as a few old Beetles.)
it causes you engine to run more efficiently, by allowing spent exhaust gasses a less restricted path from the engine, in turn allowing more fresh air to come in, and maximizes combustion.
I’ve driven said Porsche, at high speeds (engine at full revs, so max heat), with an aftermarket exhaust, in Death Valley, and it absolutely refused to overheat. And I’d say it probably has worse engine cooling than a bike, as the engine is covered.
It could conceivably be a problem if you were in a traffic jam, as cool air wouldn’t be rushing over the engine to cool it, but i doubt you’ll have a problem.
usually with an aftermarket exaust, you need
to rejet, the bike runs hotter because it is
lean….
NO! it won’t make it run cooler!
NO! it won’t give you more HP!
I don’t know whats with you guys when you say ur air cooled engine is running too hot!
How do you know its running too hot?
they are made and engineered to run at a certain temperate to run at their top performance and fuel economy, they are engineered to heat up quickly and they are timed a certain way to dissipate heat.
The best way if you want ur bike to run cooler is to use a high quality synthetic motor oil
An aftermarket exhaust wont make it running hotter or to over heat. All engines air or liquid cooled will run a bit hotter in HOT conditions but the exhaust don’t have any influence
It can cause you bike to run lean, so change out your air-cleaner to a high-flowing one and re-jet your carb (or remap you fuel injection) to keep the air fuel mixture correct and you should not have any running issues. Being in Texas during the summer, my bike gets hotter during the day than in the winter. Also if you are stuck in traffic it does not matter what you have no air flow = hotter motor. Your air cooled engine is designed to work under hot conditions, but if you are that worried, synthetic oil can help and an oil cooler can as well.
With the EPA getting more and more involved with emissions on motorcycles, from the factory they are quite lean which can make for hotter conditions.
The routing of the exhaust pipes may make it feel hotter to the rider as well. For example if the exhaust pipes ends up closer to your leg, you might feel the heat more than before.
If the pipe make the bike run lean, then it will run hot!
For the fella here that cannot tell if an air cooled bike is running hot, they first run with intermittent power, and then will soft seize. A soft seize means the engine will very briefly lock up. It is very bad for the engine, and will make a score in the cylinder each time it happens. Best to lay off the throttle, and slowly run to a stop, helping it cool. Runnig with a little choke will get you home in this case, but you need to let the motor cool down completely after that.