350x 250x/300ex swap info

[JIMFROMTEXCO]

i just left fischer cycle sales about 3 hours ago talking with bud fischer himself about the 350x swap.. you have to take the top rear Mount down to 1 1/2 inch from the shifter side of the motor and make a 4" spacer for the oppisite side, then the front bottem mount you have to make spacers to get it to bolt tight. on the shifter side you could use a 1/4" thick washer and on the kicker side you need approximently a 2" spacer.. and thats it to mount the engine. for the exhaust you can order a powroll or take the stock 350x header cut between the flange and the first bend on both sides and add about 2" of material. The top right fram rail has to be heated up and taped in approximetly 1/16th to 1/8th of an inch to clear the oil line for the head. If your using the 300ex engine kill swith it has to be in the off position to run. the 250x will work on the on position. you will also need the 350x cdi box.

im almost complete with my swap waiting on my top end to get back to me to finish but the bottom end is in the frame and my sprokets line up perfectly.

If you have te complete trike to do the swap with use the swinger,shock and axel for a complete set up.. the swinger is almost 2" longer and the axel is 2 1/4 wider..

any questions on the swap let me know i can help

[SWIGIN]

i never cut the rear mount...i cut the mount off the frame and re weld a corect mount on

[bigdaddy_chaos]

did u use the 300ex wiring or the 350x wiring ? and what carb did u use ? im building the same hybrid ... a 300ex frame with a 350x motor

[SWIGIN]

you always use the wiring and carb for the new motor on any hybrid

[bigdaddy_chaos]

do u have any pics of ur build ?

[SWIGIN]

the one with the blue frame is my 350rx... the 250x hybrid ( 350x) was built by us about 10 years ago and is still going strong.

the frame is just showing how we stretch them 2'', this makes them more roomy and 400ex size

iv done a pile of these swaps just make sure you dont cut the rear upper motor mount on the motor....you should cut the mount off the frame and make the corect one.

my motor came out of a 250x that had the motor cut and after a few months it tore off and i had to machine a new mount and weld it to the cases






http://www.exriders.com/vbb/showthread.php?s=&threadid=274580&perpage=13&pagenumber=1

[bigdaddy_chaos]

thanks for the pics but i didnt see any showing the upper rear mount changes , thats what i really wanted to see , but u gave me some real good ideas

[SWIGIN]

the first pic is my motor which was cut and the case broke

the other pics are the 250x /350x hybrid im building for a buddy

this shows how to make the rear motor mount so you dont cut the motor and weaken the cases

[SWIGIN]

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[SWIGIN]

just a shot of the cooler and hard lines

[SWIGIN]

this mount dont have to be removable, you can just weld it to the frame but this way it is easier to remove the motor

[SWIGIN]

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[bigdaddy_chaos]

thanks man that helps out alot . thats the way i thought it was supose to b done but i just wanted to make sure

[bigdaddy_chaos]

can i use a 400ex carb insted of the 350x carb ?

[SWIGIN]

sure....but if your building the motor up much at all a 38mm will work better

[bigdaddy_chaos]

the motor will stay stoke for a while and im glad to hear the stock 400ex carb will work

[zell250x]

does anyone no what jetting to run useing the 400ex carb? Im doing this aswell. All stock but bored .40 over.