DR650 engine in DR350 frame?

[Mavric_Bass]

I have searched through the forum and am surprised to find no information on this subject.

 

Has anyone done it or know of it been done? Aside from the obvious size differences the engines do look similar and the mounting points seem in the right area code lol :-)

 

Any other reasons why it wouldn’t fit?

 

Any information or even a point in the right direction would be appreciated!

[Mavric_Bass]

[plugeye]

what is the goal?

 

2 hours ago, Mavric_Bass said:

this is no 350 frame

[zig06]

6 hours ago, plugeye said:

what is the goal?

 

this is no 350 frame

Excellent point!  DR650 and most other frames are sized mostly to fit the motor, and if he's looking for better suspension for a DR650 then keep searching, there's an endless number of threads on doing that (upgrade or complete replacement).

[Mavric_Bass]

what is the goal?
 
this is no 350 frame

Hey Plugeye,

The reason or goal is this, I have a 1999 DR350X that is plated (road registered) and I love the bike to bits it has 17inch rims and is a semi supermotard it carves like a boss in the hills.

I have played with the sprockets and am running the longest ratio on standard over the counter sprockets however the engine being a single seems to be over stressed.

The engine is due for a rebuild and DR350 engines are not as common here in New Zealand parts aren’t ubiquitous where are DR650 is thick on the ground and second hand engines regularly up on our e-bay equivalent trademe.co.nz

And I won’t lie the thought of more power (insert the Tim the Tool Man laughter) is appealing.

I could invest in a 440cc kit but again cost of that VS a second hand DR650 engine comes out to about the same and in my opinion would be an easier and more stable long term solution as I am worried that the again the 440 kit is just going to stress the bottom end and I’ll be cracking into the engine on a regular basis where as the DR650 engine will always be less stressed.

So that is the plan the bike is not going to be used as a MX bike but the pirrelli MT’s RS are a fantastic tyres for carving hills and for adventure riding as I regularly go from the tarmac on the hills into the surrounding forestry and climb fire breaks.

So yeah.... Hopefully if I get enough information and if not then I’ll have to do it the hard way and buy a 650 engine and when my 350 pops and just work from there.

[plugeye]

oh ok.

what size sprockets are you using?

 

[Mavric_Bass]

I have a 39 tooth on the rear and a 15 tooth DRZ sprocket on the front.

The top speed of the bike comes out around 132 kph so cruising at 110-120 is not that comfy

[dan197man]

Mavric 

you have the NEEEED for SPEEEEED     ,,,      you can be "THE" new expert on squeeezing that 650monster into the 350frame  ,, sounds like I wont be the only envious American ,  monster motor into a tiny cycle  harharharharhar

here in the states that would be called   "red-neck-engineering"  or  more-is-ALWAYS-better       I vote drive-on and create your ultimate black-ribbon-racer , kiwi-canyon-carver , and that 650motor is completely indestructable if after 1998 clutch sprag.grenade issue and the neutral switch re-loctite   , you could even pony up with a 790kit from pro-cycle  $$$$$  if you reeeeally neeeeeed more speeeeeeedd     of course we ALL neeeed more speeeeed we just cant afford it 

keep us posted 

DDDDD     sticky keyboard from watching kiwis kick aussie in rugby ,, spilled beers  what were you thinking ??

 

[plugeye]

you can gain an extra 12% gearing from an early clutch hub swap.

late clutch hub/ drive gear = 64/20, early = 62/22

i did this on my 94 & running 14/44 is great for the street. i can go up to 15/41 or 39 for highway

[zig06]

Had to think this one over.  I'm still thinking that while it's possible to cut and weld a 350 frame to the point where a 650 engine would fit, I still think it would be better to just sell the 350 for what you can and buy a 650.  I have no idea of how the cost would work out but the end product will be better.  But if speed is your goal and you want to be different then try wedging in a GS500 motor into your 350's frame.  You would definitely have something different and faster - possibly even faster than a 650 (higher rpm limit).

[Foil]

The gs500 as a bike is a bit of a dog, but from what I've been able to research, the engines themselves should of a similar weight, with the added bonus of around 10 - 15bhp.

 

But then you'd need to add some weight back with the twin exhaust, dual carbs, and oil cooler.

 

From what I recall, the gs engine is also wider, which would be a bit of a problem.

 

Honestly, if I had a broken dr350 engine and a broken g500 motorcycle I'd give it a shot.