CDI UNITS FOR THE XT660!!!

[hb7]

Have you felt the vibration on a Duke 640.....?
It's unbelievable....I can't imagine a KTM 640 lasting more than 25-30 K miles or the rider for that matter.

[DAVID THOMPSON]

i rode a f650cs bmw 3 years ago and told the demo guy they needed
to check it out because of the vibes it did not sell me on one

[Bill Jurgenson]

I can't imagine a KTM 640 lasting more than 25-30 K miles or the rider for that matter.

THAT long?
That KTM engine has no counterbalancer and also no oilpump. It was conceived as a racing engine. even 20k mls is utopian without routine rebuilds.

But more prformance than the Yamaha unit where both are equally treated?
Sorry, you up the wrong alley. And you may notice, that there are few KTM engined SOS racers out there but lots of Yamaha engines.
When you strip the xtz engine to the bones for racing, giving is a better, lighter crank, no counter balancer, Carillo rod, etc etc etc, you get it easily up and beyond what the KTM engine will deliver for more than an hour. and you also get it near the KTM weight. My racing engine weighs 40kgs = 88lbs complete with carbs and all fasteners wired. And Oilpump! The KTM is if I remember right 39kgs.
A semi pro from the german SUMO scene test-drove my racer and commented glassy-eyed afterwards: "NO KTM goes like that!"
With ±80 rearwheel HP I am only in middle field for the xtz engine. EGU's SOS factory racer with SRX based engine was up to 85hp back then! Winning with Hansi Mayer. But then that was 1990 or so.
PAMI's BMW is reportedly up to 104ps!! We've raced against one and it was quick - till we watched it explode. My driver just said that the BMW couldn't really pull away, not on that short cicruit anyway. Maybe in Monza...

[keithcross]

While I agree with your comments on teh reliability of some KTM's, this does not always apply. The 640 models (confusingly with a 625 engine) are quite good on reliability. I have ridden a 625 SMC over the Yorkshire dales and didnt find the vibes to bad, but they were still worse than the 660 Yam engine.
In addition the current KTM engine does have an oil pump, and has done for some years. Otherwise it would be difficult to have a paper element filter fitted. Maybe you are getting a bit confused with the Husaberg engine. These are produced in the KTM factory and dont have an oil pump fitted.

Keith

[DAVID THOMPSON]

THIS POSTING WAS A WAKE UPCALL FOR ME

i will be asking to see the engine parts drawings on any new bike
i buy to make sure it has an OIL PUMP

suzuki had a autolube system in 2 smokers in the lat 60's early 70's
that put oil in on the mains and also at the carbs
no oil pump on a 4 stroke is big time dumb even for a race motor

[keithcross]

Dont worry, the 125 and 660 motors that MZ use, both have oil pump fitted.

Keith

[buckwheat5679]

Husaberg's have had oil pumps since 1999, not that it helped much.

[Bill Jurgenson]

read what I wrote: "THAT" is what I wrote, meaning that particular engine.
None of the early 4 stroke KTM engines (LC4 etc) had an oil pump. All do now. None of them had a counterbalancer either; the newest do.
Wet sump engines to run in the dirt often had no pump. Thay are also always rollerbearing engines. Splash is good enuf for the crank. The problem with the KTMs and also with some track engines is that the cam only gets what little the timing chain takes with on its way up. That's fine for the ballbearings but not really for the followers.

Old-time dirt (grass) track engines were in fact drysump and with a one way oil circuit, also called constant loss. Oiled was scavenged from the crankcase - out onto the chain. No return to the tank.
They only run 8 laps if the alcohol burners last that long.
Many road bikes had a relief valve in the return oil line that allowed an adjustable amount to drip onto the chain. Even the 2-stroke Scott (had a separate oil tank in the 20ies!) had an oil-metering system for the chain.

[keithcross]

Bill

Sorry to disagree with you again, but the engine your THAT comment refered to was the 640 LC4 KTM engine, which does have an oil pump. The LC4 engine is current up until the new 690 engine for 2007 is out.
I am however unsue of the other current 4 stroke KTM engines as some are differnt to teh 640 LC4 engine. Not sure which size engines they are, but they have their chan drive on the same side as the Yam engine. I think maybe the 450 and 525 engines. I am also not to sure, but they may also be designated as LC4 engines.

Keith

[whysub01]

Recently been lucky (if that is the right word) to have use of two KTMs (a 625 LC4 and a LC4 640 Adventure) and a Derbi Mulhasen (with the new 4 valve Yam 660 engine).

Both vibrated far more than the 5 valve 660 motor. The 625 felt very fragile and extremely vibey, whereas the Adventure felt a little softer enginewise, bt still vibrated like a bastid.

As for the Mulhasen-looks retro cool, and also allows you to change the ignition mapping via the left hand handlebar switch. Seemed to work, as there was a difference at low revs between the two settings. However, i was very dissapointed at the level of vibration. White knuckle stuff.

Maybe my engine is unusual in being very smooth, but I very much doubt mine is the only one.