78 KTM 400 MC5 needs transmission work

[PaulEricksen]

My 78 400 MC5 started missing shifts especially 4th to 3rd.  It's been getting progressively worse, and now is at the point where I need to fix the problem.  I have the repair manual from Al Buehner, but I don't have all the special tools that are referred to.  My question is,  is there anyone near Southern California who has experience working on this motor.  I'm mechanically inclined and good at maintaining the bike, but splitting the cases and overhauling the transmission without the special tools may not be a good idea. I am in need of some expert advice. here is a link to a recent photo http://paulericksenrecording.ning.com/photo/2186719:Photo:94?context=latest

Paul E

[chicagojerry]

hi paul, welcome to the site.
i'm not located close to you but i can offer you some insights on how to rebuild it. feel free to drop me a line at [email protected]
chi jer

[tomale]

welcome to the site paul,,, If I remember right, Big Mac and I split the cases on my 78 with very few special tools...Mac had fashion three alignment dowels out of wood.. and then you will need a ignition puller but those can be had pretty easily....  The clutch side of the engine does not need to be taken apart so splitting the cases from the ignition side should make things alot easyier.. Maybe Mac will chime in here...

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)74'
250 hare scrambler (project bike)

[Rocket]

The (3) alignment dowels for the transmission shift forks are not really necessary.  It is a little easier if you have them but I take a phillips screwdriver and align the shafts with the case as I put it together. As long as you are leaving the crank in the other case half, a flywheel puller is the only special tool needed.
Rocket

[garrettccovington]

Hi Paul,  and welcome to the group,  Sun-Tues,  I live in Chino Hills.  The rest of the week I'm out in the middle of nowhere (Desert)  I guess the only special tool I have is the flywheel puller for a 79 KTM 250.

G

72 six-day
79 KTM MC80 250

[Big Mac]

Paul - very easy to get the right side case off, work on the transmission, and get it back together with nothing more than a mag puller. You'll need one anyway for other maintenance like seal replacement and timing adjustment, and not expensive. A low cost electric impact wrench from somewhere like Harbor Freight makes getting the big nuts loose an easier task, and you'll find lots of uses for it.

A copy of the service manual walks you through it. All the gears and shafts will stay in the left side. Likely the shift "claw" is spread too wide (I've fixed by bending in a vise back to spec opening size) or a shift fork is bent. Should be pretty easy to see what's wrong when all is apart and you see how it works together.

[tomale]

Yea, that is what was wrong with my 78  it was shifting hard and missing shifts which should not be. I can see it if you have a CZ but not a KTM motor... As it turned out, not only was the "claw" too wide, it was also bent... or am I wrong and it was broken and we replaced it with one from another motor... Mac which was it,, I've got a good memory but it is just real short...

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)74'
250 hare scrambler (project bike)

[PaulEricksen]

Thanks for all your welcome words, and the details on your experience with this issue.

I am looking forward to getting into it it the coming days.  I'm sure I will have more questions as I go.  I plan on taking my time, to do it right.  

This motor has never been worked on.  Never even had the head off!  It has never been raced, only ridden in the desert.  It sat for 15 years in my garage, until 2004.  Now I get out 4 or 5 times a year (I wish it were more often).

I'll keep you all posted on my progress.

Thanks again,  Paul E

A former CZ rider in the 70's
KTM owner since 1980

[tomale]

I feel fortunate, I have a 76 250 KTM that has never had the cases split and it shifts so nice... In 04 I broke down and put new rings in the bike... I don't ride the bike much but I started the bike the other day, ( plan on riding it on Saturday) and it fired on the second kick, I wish my other bikes started that easy...

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)74'
250 hare scrambler (project bike)

[Lloyd Boland]

Welcome Paul.

If you get into trouble and need local help in Souythern California, try Vintage Iron.  Rick has a great deal of experience with all types of bikes.  He is on the Suppliers page.

Also, I rode CZs for Mid-Valley in the early to mid-70s also.  Still race a couple of CZs along with my "76-77 MC-5", my '91 KX500, my '08 KX450F, '89 YZ 250, etc.  Come on out to one of our races at Glen Helen.  About once a month. Classes for everyone.  Great times, Great guys.  (Garrett will probably chime in.)  

Hope to see you there.

Lloyd

[PaulEricksen]

Thanks for the info Lloyd,

My Dad's riding buddies from the seventies all bought their bikes from Mid Valley CZ.  In fact my KTM was also purchased from there (It still has the Mid Valley sticker on the side panel).  The original owner of my KTM was a loyal Mid Valley customer, and just made the switch from a 74 CZ 400 to the 78 KTM 400.  

I'm more of a desert rider (Dove Springs is a favorite place), but I look forward to getting out to the track in the near future!

Did you race at Mammoth back in 74 by any chance?  or the Elsinore GP? I remember John DeSoto winning it in 71

BTW where do you live these days? (if you don't mind me asking)

Paul E

[Lloyd Boland]

Paul,
Been living in Moorpark (old Bay Mare area) for 25 years.

We still play ride the modern bikes in the Desert, mainly the old Charlie's Place (now called Wagon Wheel).  Previously rode a lot around California City, Jaw Bone, Dove Springs, etc.

My first CZ was a 1971 400.  Bought it in September 1971.  I bought it used from Mid-Valley and it was Bob Hershey's bike.  (Bob rode for Mid-Valley.)  Over the years I did a lot of work to that bike, even had EC Burt do a complete engine modification to it with a reed valve, a Bing carb, increased compression and a completely redone combustion chamber, different pipes, etc.  That bike was a rocket.  Had the shocks moved up, Curnutts (Charlie Curnutt actually came to Indian Dunes to tune the shocks).  Those were great years (1971-1976.)  The bike sat in the garage for years, I stopped riding and I dumped it into a dumpster in 1987.  (I could just cry about it today.)  Started riding again in 1991.  I now have 3 CZ 400s, and they all have motor work, but none come close to that original bike.  I wish I had the specs on what EC Burt did.  I love the handling of the MC-5, none of the CZs handle like it.

I did not race Mammoth or Elsinore.  I raced Indian Dunes a lot (2-3 times a week, night races during the week and Saturdays and Sundays), and usually Saddleback and Carlsbad once a month, Lion's drag on Friday or Saturday night, etc.

I just couldn't get enough riding in those days.

Hope to see you out at an ARX Retrocross race soon.

Lloyd

[PaulEricksen]

Hey Lloyd,

We are very close.  I've been living in Simi Valley for 20 years.  I grew up in the south bay area (Harbor City) not far from Lion's and Ascot.  Also used to go to Saddleback and Indian Dunes, I was just a kid at that time.  I would love to come see your bikes sometime.  My email is [email protected].  

I live off Royal and Sycamore in the middle of town.

Sometimes it's a small world.

Paul E

[Lloyd Boland]

Smaller than you think.  I've been a chiropractor here in Simi Valley for over 27 years, on Tapo Street.  I treat many of the local motocross guys.  One of my guys just won the Vet Pro races in Mammoth over the weekend, took overall on Saturday and Sunday.

[PaulEricksen]

Well, I split the cases without any problem and quickly discovered the problem.

The hook/claw on the shifting quadrant was broken and laying in the bottom of the case.

Also, as I went to remove the shifting drum it just fell out of the other side of the case.  The bushing on the clutch side of the case had broken off inside the drum.  The broken part is rolling around inside the drum.  I can't imagine how to get it out of there.  Maybe try to drill it into pieces perhaps.

Does anyone know if these parts are available?

Other than that everything looked good inside.[8D]

Paul E