Building a drag blaster

[Curtis Harriman]

I'm building a 89 yamaha blaster with a yz 490 but my question is can the original blaster frame handle the 490 or should we enforce the frame?

 

[Larry's Shee]

Search Pauli B. He did a 490 for trails, don't recall exactly what he did as to gussetts, but it did crack in the end. You would have to look closely at the frame as to where you might need gussetts, probably mostly around engine mounts/tubes.
Might as well also look for a spare frame just in case. because you will want to remove as much as possible in noncriticle areas.

Highly suggest inspecting frame after every race meet.

 

[Jimmer]

I put a Honda CR500 engine in a Yamaha bike frame.It never tore up any frame mounts or tubes, but it shook the crap out of the exhaust and side covers.Just needs to be inspected once and awhile.

 

[Herpderplol]

Yes you need to reinforce the crap out of your frame

probably more than twice the weight and twice the power pulling on the poor blaster frame

 

[Curtis Harriman]

Thx

 

[best]

This is a 2003 KTM 250 SX in a Blaster frame.

It makes 40-50hp and has no counter balancer.
This is enough power to wheelie or spin at any speed.
The only cracks I have had have been at my MIG welds.
Chromemoly does not weld well.
Your frame re-enforcement may cause more cracks than the frame as it is.

Steve