engine swap

[redrider330]

okay first of all i thought i broke my timing chain about 2 months ago so i tore down my engine this weekend hoping 2 put a timing chain on and thats it well i found metal shavings in the carb and i found out that i had dropped a valve and bent another tore my head up so i need a new head and crap and i was thinkin about dropping a new motor in i know u can drop a 250x and a 350 x in pretty easy is there any other motor tha would drop in like say 400ex 450r quad or a crf 250r bke motor and another quesytion will a 250x bottom end work with a 300ex top end cause i want a kickstart if i could get it because the 300ex electric starting aint worth nuttin lol so please help me decide wat i need 2 do thanks

[riderssb250x]

the 250x bottom end will work with the 300ex top end its nice with the kickstart i have a 250x and the kick start is nice and plus the stroke on the 250x is shorter so tahts a plus to and i hear that the 250x bottom end holds up better then the 300

hope i could help thanks

[beaubs]

250x and 300 ex are the same motors with exceptions.
The crank is different as the fly wheel end is longer on a 300 to make room for the starter gear.
The stroke in shorter on the 250.
heads the same.
cam the same.
250 is a kick

250x in the big brother to the 300

a change you need to make is to remove your lower crank case breather hose.

the plastic will be fine cause if you look the 300 plastic has the cut out for the kick already

[markvette]

i have a spare head i will sell for $75 plus shipping. nothing wrong with it, i took it off to put a ported head on.

Mark

[redrider330]

okay markvette i will prolly buy that head if u dont care will u put pics on for me and does it come with the valves and all that already on it and so u guys r saying that i can drop that 250x bottom end in with no problems not change ne thing even know it has a shorter stroke it will still run fine appreciate it guys

[bwamos]

You'll need a 250x wiring harness and CDI as well. The electrical is different (battery vs. direct stator)

[markvette]

it needs cleaned up but i will do that before i ship it if you buy it.



http://i114.photobucket.com/albums/n246/quaddad1958/100_1852.jpg

[beaubs]

Originally posted by bwamos
You'll need a 250x wiring harness and CDI as well. The electrical is different (battery vs. direct stator)

that and your breather hose on the bottom of your head goes away.

[redrider330]

ok thanks and i c y i might have 2 buy a cdi box but do ya have 2 buy the whole wire harness and the shorter stroke so i hera give it more bottom end power right

[JIMFROMTEXCO]

THE SHORTER STROKE MAKES IT REV FASTER. you will lose displacement

[dabomb_350x]

You have to get a wiring harness, too. And the air tubes are the same on the 250X and 300EX until 98 california bikes and 99 and new.

[bwamos]

Aye, shorter stroke will rev up faster and have the HP curve a bit higher up on the rpm curve.

Strokers have more low end grunt.

I personally like the 250x characteristics more. I like play in the higher revs, I'm not much of a low rpm lugger.

Yes you need the new harness. You can get them off of e-bay pretty cheap. The stator powers the system differently.

You could manually rewire.. but the harness is MUCH easier, and probably cheaper in the long run.

[redrider330]

so markvette how do i get up with u 2 buy that head and crap

[markvette]

i take pay pal or money order. shipping should about $15 so the total would be $90. if you pay pal i could ship out the next day. if you send a money order i will ship out after i get the money order. let me know how you want to do it.

Mark

[redrider330]

so the valves comes with it and there good and the valve springs and the head is good if it would be alright with ya if i could maybe wait until end of week or next week 2 buy it im gonna buy it prolly 4 sure so just hold it 4 me
do u have a paypal on ebay or something

[markvette]

yes comes as in pic. valves springs everything. no rockers or cover. no problem on holding it as i have 2. is your 300ex bottom good. if so we may be able to work out a trade. i need a 300 bottom end. our chain came off and knocked a hole in the left case.

Mark

[redrider330]

yea far a si know it is the only thing that i can think of it will need a good cleaning had some metal shaving from the piston and head and it leaked just a lil oil on the left side it was just a lil damp there and there must b some lil bushing on the fly whell cause when u hit the starter button i just spu u could here the gear spin but if u rocked it a lil bit it would fire right up
and the transmission and all that is reall good
it shifted good and the rod and eveything is good wat kind of trade we talkin about