KTM 380 on a 300"?

ucfmotorcycle1 · 11-15-2004, 8:08 PM

I know this is the wrong place to ask but I have looked all over over and maybe someone knows or can google better than me. I have a 95 KTM 300 MXC recently rebuilt and recently seized due to a loose rod clip

. I am claimiong manufacturer defect. The small clip messed up the cylinder piston and head. While I am sending these parts back to Wiseco to see if they pony up the dough (which I doubt)

. I happened to come across an entire 380 engine. I was wondering if I can use that top end and mount it on my bottem end. They look exactly the same and it seems like it would bolt right up. I figure just change the jetting to 380 and it should work. I'm wondering if anyone one knows if these bike share the same bottom end and the same crank.

Mavic · 11-15-2004, 8:57 PM

It might work if the stroke is the same and the exhaust, intake and water ports line up. I did the exact same thing on an aircooled RM100 back in the early 80's by putting a 125 head on the stock cases.However, I was dealing with a mere 25cc of additional displacement and you are contending with a significant amount with 80cc. Then again, the CR's had 2 different stroke lengths for the same displacement motor between 86 and 87. That kind of difference will cause some serious problems.

Good Luck!!

On another note, would the 380 not mount up in the same frame???? Then you get rid of the whole issue.

ReaperAZ · 11-15-2004, 9:18 PM

Quote:

Originally Posted by ucfmotorcycle1

I know this is the wrong place to ask but I have looked all over over and maybe someone knows or can google better than me. I have a 95 KTM 300 MXC recently rebuilt and recently seized due to a loose rod clip

. I am claimiong manufacturer defect. The small clip messed up the cylinder piston and head. While I am sending these parts back to Wiseco to see if they pony up the dough (which I doubt)

. I happened to come across an entire 380 engine. I was wondering if I can use that top end and mount it on my bottem end. They look exactly the same and it seems like it would bolt right up. I figure just change the jetting to 380 and it should work. I'm wondering if anyone one knows if these bike share the same bottom end and the same crank.

Check out www.ktmtalk.com they have all kinds of info there.

Dano

SomeStrangeGuy · 11-16-2004, 2:38 AM

thumpertalk.com too - has some decent info (even though you're smoking, lots of 2smoke guys ride strokers too).

ReaperAZ · 11-16-2004, 8:17 AM

Quote:

Originally Posted by SomeStrangeGuy

thumpertalk.com too - has some decent info (even though you're smoking, lots of 2smoke guys ride strokers too).

I suppose you could try thumpertalk as well. There are a lot of guys who have or have had 2 smokes and I'm sure will help you out. They just updated the forum so some posts may be lost in the transfer.

Dano

ucfmotorcycle1 · 11-16-2004, 4:32 PM

Quote:

Originally Posted by Mavic

It might work if the stroke is the same and the exhaust, intake and water ports line up. I did the exact same thing on an aircooled RM100 back in the early 80's by putting a 125 head on the stock cases.However, I was dealing with a mere 25cc of additional displacement and you are contending with a significant amount with 80cc. Then again, the CR's had 2 different stroke lengths for the same displacement motor between 86 and 87. That kind of difference will cause some serious problems.

Good Luck!!

On another note, would the 380 not mount up in the same frame???? Then you get rid of the whole issue.

I would use the whole engine but it has issues with the transmission so I would have to take apart the whole thing, I guess I am just trying to do it the easy way. Hope it works.