Reader Digest Version (Short)
Did KTM/Penton run out of parts in 1978/79 when they switched names in the US due to finacial/inventory problems and slap together bikes with whatever parts they could find and fit? (sorta)?
I'm beggining to wonder if they mix mashed the clutch like the carb? Can it be mix-mashed?
My version (long)
On my 79 KTM 250 I've noticed that there seems to be a mix mash of parts on the bike. For instance, the carb had a 125 slide, 400 main jets and 250 idlejets, jet idle (I always get those 2 mixed up). Also It never had the 2 top rear engine brackets/rods/bar/things.
It also had the GS rear fender loop grab rail thing on it at one time, but no side stand. Nor did it ever have the complete GS package. Headlight/tail light. Only parts of it.
Now, I'm beggining to wonder about the clutch. It is so stiff and hard to pull in it affects my riding. Re-routing the cable helped, I even found a set of longer magura levers at a local swapmeet for 2 bucks and that helped too. But after 2 laps of racing its so stiff I can barely pull it in and I have to really think about it. I am amazed how much this effects my riding. Especially in the tight corners.
I've switched to ATF and when I bought the bike, the tranny was COMPLETLY full of oil. I think that kept the mag rot down. I also believe that due to the carb being so out of wack the original owner had such a problem keeping it running, he put in a resistor type plug in it and it blew out the moto-plat. After that, he must of said screw it and parked it for 30 years.
It doesn't leak a drop. Now it starts 1st kick every time and Idles perfect.(Thanks to You POGers) It had every little decal on it (trans-am) on the bars Sun rims on the rims Made in Austria on the neck. It even had the stock tires on it. (I'll sell those on Evil Bay for $1000)
I haven't pulled the head, I haven't taken off the clutch cover. Basicaly all I've done to it is, fix the moto-plat rejeted it and put new rear fender and side panels on it.
But that clutch is horrible. It doesn't slip, Its just super hard to pull in. It feels like it has V-8 valve springs in the clutch and takes Popeye arms to ride it. I'm even starting to look for some sort of hydralic thing to graft onto it.
G
72 six-day
79 KTM MC80 250
Garrett,
Since you have no complaints with regard to other clutch concerns and if you haven't already done so, I would replace the clutch cable with a new Terrycable. Those old cables can require a lot of energy, especially the clutch cable.
Tony
May I suggest disassembling the clutch basket carefully. Look for grooves in metal that should not be there. Too many plates? Make sure the actuating arm works smoothly, and all other mechanisms. Be thankful someone messed up your KTM, or they would still be riding it, not you! Joe
Toy
Actually, I did replace one from Terry, They are right down the 15 in Victorville. Whats funny, I ordered one from Al B and it actually was cheaper from Al than going to Terry.
Joe
I was afraid you were going to say that. Yea,, I gotta do that. The actuating arm is perfect. no leaks, nice and smooth. So Its gotta be in the clutch basket itself.
G
72 six-day
79 KTM MC80 250
Plus they had too stiff of clutch springs.
I put in lighter springs.
much better.
Bob
1986 ISDE Italy
1987 ISDE Poland
1989 ISDE Germany
1973 Jackpiner 175
1974 Penton 250 Harescrambler
1976 Husky 250CR
1985 Husky 400WRX
1985 Husky 400WR
Quotequote:Originally posted by Bob Bean
Plus they had too stiff of clutch springs.
I put in lighter springs.
much better.
Bob
1986 ISDE Italy
1987 ISDE Poland
1989 ISDE Germany
1973 Jackpiner 175
1974 Penton 250 Harescrambler
1976 Husky 250CR
1985 Husky 400WRX
1985 Husky 400WR
Hey Bob, Where do you get the lighter springs from??? Thanks, James
I'm with Ski,,, Where do you get lighter springs
G
72 six-day
79 KTM MC80 250
A little off the mark but on RL250s in addition to all the friction and geometry ideas (cable bend, etc) they suggest alternating soft and stiff springs to moderate the pull weight while retaining proper grab. On Sherpa T's they say eliminate a plate or use a brake arm instead of the clutch actuator (don't think this last part would suit you though). Good luck maybe you can just tie a 5lb plate to a rope and practice/practice/practice. :) John:D
According to the '79 parts manual, the 250/400 motors use a clutch spring with a 1.7mm wire diameter (part number 510.32.001.140), while the 125/175 motors use a lighter spring with a wire diameter of 1.5mm (part number 510.32.001.120).
When you get the clutch cover off, the first thing I would check is to see if maybe the springs are tighten down too far. I don't have a repair manual in front of me, but I think there should be only 2 or 3 threads showing on the bolts.
I think you're on the right track with checking for a worn clutch basket, but also check for wear on the inner hub. Around '78 KTM changed the inner hub material from steel to aluminum.
This motor should have a long, one piece push rod with a caged bearing on the end. When you pull the rod out, use a straight edge or chuck it up in a lathe and make sure it's not bent. If it's bent, it will be rubbing the inside of the mainshaft when you pull the clutch lever in.
On my motors with the one piece push rod, I modify it to resemble the 3 piece set up used in the older motors. I first measure the overall length of the rod, then cut it in half, place a 6mm ball bearing between the rods, then grind the end off of one of the rods to get the overall length back to where it was. This keeps the rod from getting bent or flexing inside of the mainshaft.
I have had Hoosier spring make me some in the past.
Also in the past we went thru other brands to find springs to fit.
Sorry, I cant tell you what we used .
The last one I changed (76-250)was back in the mid 80's and I dont remember what we used.
Bob
1986 ISDE Italy
1987 ISDE Poland
1989 ISDE Germany
1973 Jackpiner 175
1974 Penton 250 Harescrambler
1976 Husky 250CR
1985 Husky 400WRX
1985 Husky 400WR
All Right that sounds like the path I'll go on. I'm racing this weekend and I'm gonna give it 1 more try befor I mod it.
G
72 six-day
79 KTM MC80 250
How about one of these, Garret?
(http://i303.photobucket.com/albums/nn155/OhioTed/dk57706.jpg)
YOU GUYS ARE NOT GONNA BELIEVE THIS!!![8D]
It turns out, I was running to much tire pressure. Somewhere in my pea brain, I got the idea I needed to be running between 38 and 42 lbs pressure in the tires.[:0]
My Buddy was laughing at me so hard, he could hardly spit out that I needed to be running between 8-14.
The difference was unbelievable! It actually went where it was supposed to go in the turns and I was actually able to use the suspension to dance over the top of the whoops! AND the jumps, FUN, FUN, FUN. Its a whole new bike! I still can't believe it.
Now, I like the feeling of shear Terror, just as much as the next guy, but after a year, it was getting old. If you didn't have the bike just at the correct angle in the corner, it would either want to low side or push out BAD!
The only reason I won the championship last year is the other guys, kept falling down and by time they got going I'd be able to hang on for enough wins to win the War.
Now the bike runs PERFECT.
I know some of you guys are laughing your heads off too. I know I am.
G
72 six-day
79 KTM MC80 250
Quotequote:Originally posted by OhioTed
How about one of these, Garret?
(http://i303.photobucket.com/albums/nn155/OhioTed/dk57706.jpg)
What is it?????
It is called an EZ Pull and goes in-line on your clutch cable. There is a pulley mechanism in the unit that increases leverage and makes your clutch cable easier to pull. This one is sold by Moose Racing and can be had through any Parts Unlimited dealer.
Larry P