Stock Fe650 at highway speed- endurance concerns

i think it's very bad for the transmission rather than overheating. these are race engines designed for short bursts down a straight before braking into a corner. they weren't made for what you want. you can try it but that don't make it smart to do it.

find a cush drive for the rear wheel.

Taffy

May I suggest you adjust your final drive gearing to suit the conditions. (ie Reduce engine rpm to that of roughly 50% of maximum power for constant speed operation)

Hope this helps.
Best Regards,
Dale

This is a very interesting topic ! It is "common knowledge" that a husaberg, or a husky, or any other competion-oriented 4 stroke mono is not suitable with highway use.
But exactly why ? I find it hard to believe that the components, like conrod, piston, or the crank would be made of inferior material or were poorly engineered. Since 1999 they have a serious oil system, before that time, I can understand why people better not used them on highways...
The cooling system is strong enough to last for 2 x 40 minutes grand prix races, at average speeds of 50 to 55 kilometer/hour. So this is not an ideal situation for receiveing much cooling. And yet the engines support this. It is true that the total amount of oil is limited. But when you change it every 300 km, is this really a problem ?
The transmission : yes, the engines and also the transmission were designed for off road use, not for maximum grip on tarmac with 5 inch rims, equipped with sticky road tires. But KTM and Husaberg sell wheels with a cush drive, so a solution is within range.

Now, if a person should change oil often and regularly check the leveln only use synthetic oil of the best quality, use a wheel with cush drive, install a final gearing that is suitable for road use, and drive normally (not at 160 km per hour for extended periods) then I cannot see why these engines would not be able to support this. A mono that is spinning at 6500 rpm, well serviced, using good oil, and receiving plenty of cooling at 120 km/hour should suffer less then a bike that is driven in the woods or in a dessert.
Or am I overlooking something ? Dale, I would very much apreciate your opinion on this assumption.

Hi Xmen,
The Cush Drive will indeed reduce drivetrain overload and consequent component failure.

In my humble opinion the primary area of concern is that of high sustained engine rpm.

Regarding an offroad oriented single:
With most as delivered overall gearing and tire roll out one will be near peak rpm @ highway speeds. Since fatigue failure is accumulative sustained high rpm operation sharply reduces component life.

Hope this helps.

Kind Regards,
Dale

I heard that the combusion temperature (don't know the correct term in english) was an issue. Not the overall temperature of the engine in other words.
The issue is (what I understand) that when you run flat speed you can let down the throttle so low that you might run the bike lean for a long period of time riding it on highways and that that would cause the oilfilm to crack with the result of severe engine damage. I always give my bike full gas once every 20 seconds or so for a period of 1 second +- to cool it down if I have to ride under those conditions and that have helped me to minimize the problems of engine damage when I have to ride transports...
I know this problem exists especially with 2-strokes and it should be a reason of concern even on a Husaberg that is mainly tuned for acceleration and braking, not for flatspeeding. Put the throttle needle up one or two steps would probably be good, or change to a vacuum carb. *uacks*...

Daniel...

I ran 15/40 gearing, cush drive KTM motard rims/tyres and had no problem with over rev or over heating at the speeds you're talking for rides of a couple of hours on FE650 03 model.

Hi Daniel,
Wide open throttle near peak horsepower rpm is where maximum heat is generated. Unless abnormal combustion takes place (ie Detonation, etc.) due to an excessively lean cruise setting combustion temperatures shall be lower during sustained cruise than that of W.O.T.

A pre-mix dependent two cycle is sensitive to light throttle / high rpm operation as the lubrication volume is dictated via the A/F ratio and total fuel flow.

Fontana302,
What is your normal cruise operating rpm range with your present setup?
What is your rear tyre roll out? (actual loaded rolling circumference)

Kind Regards,
Dale

civi

the problem is that you're answering your own questions!

heat build up during high speed work and the resultant wind resistance means the engine is always generating huge heat. it's designed so that on decel a rich mixture on closed throttle enters the cylinder and helps cool the bike for a short moment.

then you have too much oil delivery on decel, then you have the knobbly acting as a cush drive as opposed to a road bike tyre with no forgiveness.

it might not be the radiator that lets you down it could be the head design-or something else.

they weren't made for what you want to do unless you're prepared to continually fettle it all the time. a CX500 it ain't!!!!

Taffy

I got a slightly tuned 650SM 2002. I have done over 4000 kms on the road, riding it like it was on a track. I change the oil and clean the stainless steel filter every 5 hours. Last weekend I rode near solidly for 4 hours taking my bike over to an island on a ferry. I burnt / lost a slight bit of oil during the day. Other than that in 25 deg C temperatures, no problem.

As long as u stay on top of valve adjustments and oil changes, u will be fine. Stop worrying ! :?

My .02 I could care less what they recommend I do what I want and I make sure everything is up to par for what I do. I suggest you talk to a motor builder and someone that knows the bike inside and out. Yes my opinion is stupid and I don't recommend it and yes i'm an idiot for posting this. But oh well. The way I see it they have limits that they tell you. But the bike is tested much harder then the recomended limits. So in my opinion you can safely go above these if your skilled enough. They test for idiots like me and put the safety recomendations much lower then the capabilitys of the bike. See what I meen.

Well, what ever the reason it will brake sooner or later. Especially at highway use. Service every 5 hours will help to get the brake downs more rarely but sooner or later something WILL happen. Show me a FS650 with 20000 kms on it that had no engine problems (out of what can be concidered to be normal) that took opening the engine to fix it and I'll buy you a beer for each one of them.
I have at least 40 people I know riding FS 650's and none of them had ridden +15000 kms without opening the engine to change some broken bearing, broken rockerarms, gearbox, piston, cylinder etc.

But!
We all (at least all of us) know this and pay that price to ride the bikes we love to ride.
Mine is opened up for a complete revision every 15 hours and still it blows the occasional bearing. Now, mine is very tuned but anyway.

When something happens, the engine is on my workbench totally open in 90 minutes after I start working on it so in an evening it's opened, fixed and put back together normally. Blew the double bearing + both crank bearings just last week btw... 6hours to fix it and have the bike running again.

I love Husabergs but for someone running mainly roads and not expecting to do some heavy mechanics somethimes it IS the wrong bike.
Yes, you can be lucky and have no problems for a long time but that is NOT purely from taking good care of the bike, witch helps, but to a certain dergree pure luck.


Daniel...
www.supermotard-racing.com