250 2 stroke into a YZ400 frame?


9 replies to this topic
  • snookismooshsmoosh

Posted December 29, 2011 - 09:27 AM

#1

We got a few bikes (99 YZ400 and 2001 TTR125) from the same customer earlier on this week. Too make a long story short, the YZ's head is trashed and the TTR needs an exhaust.

So after calling the guy and telling him the news, he asks if we want the clapped out bike for some money off the repairs on the TTR. Uhhh.....Hell YEAH!! :bonk:

So TT'ers, any of you tried putting a 250 smoker engine into a YZ400 frame? and is there anything I should be prepared/watch out for?

Also, suggestions on best motor to use ? I figured most any would do considering they are very similar, but if anyone has suggestions it would be appreciated.

This is my first time trying a motor swap on a dirt bike so bare with me.:smirk: I will also be parting out the bottom end and carb at some point in time so If anyone needs anything let me know.

  • 2grimjim

Posted December 29, 2011 - 10:19 AM

#2

I'm sure you could get a '99 or later YZ250 2 stroke to fit. I'm pretty sure the width of the engine where it fits between the swingarm and the swingarm pivot are the same diameter. This would make thinks like chain alignment relatively easy. You'll probably have to to some major surgury to get the YZ250 2 stroke exhaust to fit though.

  • 2grimjim

Posted December 29, 2011 - 10:22 AM

#3

Too make a long story short, the YZ's head is trashed.


What's wrong with the head? Used ones can be had for a lot cheaper than a used YZ250 2 stroke engine.

  • snookismooshsmoosh

Posted December 29, 2011 - 11:23 AM

#4

What's wrong with the head? Used ones can be had for a lot cheaper than a used YZ250 2 stroke engine.


whoever did the valves last torqued the exhaust cam cap too tight. So the cam journal and head are scored real bad.

I tried to tell buddy he could probably find a used head on ebay for not too bad of a price, but he said he hated that bike anyways and didn't wanna put much into it. ok??


I was thinking of going the yz route anyways. Seeing as they still make them, I wouldn't have any trouble getting parts from various yet to fit. and it would be cool to keep it all Yamaha.

  • 2grimjim

Posted December 29, 2011 - 03:17 PM

#5

Seems like a lot of money and work for a bike that won't really be worth anything to anyone but you.

But......if that's what you want, go for it.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • grayracer513

Posted December 29, 2011 - 04:56 PM

#6

whoever did the valves last torqued the exhaust cam cap too tight. So the cam journal and head are scored real bad.


Engine Dynamics can repair most of those for about $300.

  • snookismooshsmoosh

Posted December 29, 2011 - 05:03 PM

#7

Engine Dynamics can repair most of those for about $300.


Where exactly is Engine Dynamics? I'm up in Canada right now so shipping might be a bit pricey both ways.

  • grayracer513

Posted December 29, 2011 - 05:39 PM

#8

The link I posted takes you to their web site. They are located in California.

  • bonehead7101

Posted December 29, 2011 - 08:26 PM

#9

why not sell it for parts or part it out, why would you want to put a motor with less power in a steel frame?? im sure someone could use it rather than tearing it all apart?

  • snookismooshsmoosh

Posted December 31, 2011 - 09:19 AM

#10

why not sell it for parts or part it out



I like the idea of parting it out, just not so much the part where i have to wait and hold on to these parts for a while. Maybe I'll put her in the local classifieds as a complete parts bike.





Related Content

Forums
Photo

05 yz450f not fast enough by RedeyeYZ


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  38 replies
Forums
Photo

Megabomb Fitment by 288yz450


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply
Forums
Photo

2016 YZ450 by CaptainKnobby


Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies
Forums
Photo

BIGBORE FOR YZ450F 2006? by Taattie94


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 5 replies
Forums
Photo

Should I buy this bike? help....... by Numsa Hul


Dirt Bike   General Dirt Bike Forums   What bike should I buy?
  • * * * * *
  • 10 replies
 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.