Hello new guy with a 80' KDX250 and crankcase seal problem,

[cr500mike]

I bought this bike from a guy while I was working on his house, March of 2012, time flies.

He bought it from his neighbor who bought it brand new in 1980 when he retired to run errands while he & wife were traveling the country in a Winnabago RV.
The guy I got it from -Kenneth used it to explore/ride around Eglin Air Force Reserve on weekends.
I haven't ridden it more than 4 -yes 4 miles, it has 757 original miles on it, I have other bikes.
Just thought I'd give a little background ofnthe bike.

Now, I decided to ride it a bit - it ran like a champ when I first bought it 10+ years ago. I replaced the old Goodyear tires, side cover plastic and headlight surround were as brittle as a potatoe chip so I bought all new plastic except for the gas tank.

I thought it was a dirty carb, but have cleaned it thoroughly - 99% sure it has a bad crankcase seal. I've never split cases or been that far inside of an old 2-cycle. Anybody know of a reputable company or person who can replace whatever it needs for a fair price?
Or I might try and do it myself?

Thanks for any help...

[SS109]

Sadly, the cost is quite prohibitive to farm out the work. I think Millennium is charging over $1000 plus parts to do a 2T rebuild.

Honestly, splitting the cases isn't that hard if you have decent mechanical skills and the tools.

[KDXGarage]

Read up here and elsewhere on pressure and vacuum tests before taking it apart. Good luck!

[cr500mike]

Sadly, the cost is quite prohibitive to farm out the work. I think Millennium is charging over $1000 plus parts to do a 2T rebuild.

Honestly, splitting the cases isn't that hard if you have decent mechanical skills and the tools.

SS109 , I figured it would be around a $1,000 - which is expensive - add in parts and shipping both ways it wouldn't be worth it.
I searched for a KDX250 shop manual that's been hiding for a few years and found it -lol. It has a lot more information than I remember it having.
I'll tackle it myself -thanks for the help.

[cr500mike]

Read up here and elsewhere on pressure and vacuum tests before taking it apart. Good luck!

Thanks KDXGarage , I'll research it before I start.
I saw something on YT video about pressure testing a 2 cycle engine and it was leaking in more than one place.
Thanks for the advice/comment.

[KDXGarage]

Cool. You're welcome.

[SS109]

Sadly, the cost is quite prohibitive to farm out the work. I think Millennium is charging over $1000 plus parts to do a 2T rebuild.

Honestly, splitting the cases isn't that hard if you have decent mechanical skills and the tools.

SS109 , I figured it would be around a $1,000 - which is expensive - add in parts and shipping both ways it wouldn't be worth it.
I searched for a KDX250 shop manual that's been hiding for a few years and found it -lol. It has a lot more information than I remember it having.
I'll tackle it myself -thanks for the help.

You can do it! You'll save a lot of money and learn a lot about your bike, and dirt bikes in general doing it. We'll be here for any questions you have.

[cr500mike]

Yeah, I'm looking forward to it - although my truck has a little miss I'm trying to get squared away.
I'll pull this thread up when I get going on the KDX.
I've worked on Yamaha Wave Runners - those 2 cycles are simple - > no transmission etc..