motor swap question

[85ytz250nj]

i bought a tri-Z frame and i dont want to put a regular 250 in it. what is th biggest 2stroke motor that i would be able to squeez into the frame? i dont want to get too carried away with the work required, because i dont want to mess anything up. any suggestion?

[firefirefire90]

I believe Chainsaw might have your answer. If I am not mistaken, he put a CR500 motor in the Tri-Z pretty easily but you would need a torch and a welder. The YZ490 is a complete swap in though.

[85ytz250nj]

my friend has a 81yz465 and he said the motor in that bike is insain, but he also said that it wouldnt fit. thats where i came up with the idea. i was just searching the cr500 motor because i was thinking about maybe gonig with that. but if the 490 is a direct bolt in, than i might go that route.

[OldSchoolin86]

my friend has a 81yz465 and he said the motor in that bike is insain, but he also said that it wouldnt fit. thats where i came up with the idea. i was just searching the cr500 motor because i was thinking about maybe gonig with that. but if the 490 is a direct bolt in, than i might go that route.
If a 490 goes in shouldn't a 465? IDK

[clutchcargo]

What kind of pipe do you run with the 490? Can you run a Tri-z pipe or do you modify a 490 pipe?

[85ytz250nj]

If a 490 goes in shouldn't a 465? IDK

thats what im thinking since the 490 is a direct bolt in. idk though, i would probably still go with the 490. unless i find a good 465.

i would think that you would have to use a modified triZ pipe for the 490. isnt the 490 exhaust longer? unless you cut a section of it out and reweld the the conneting piece back on?

[clutchcargo]

From what I can tell, the 490 pipe runs way high on the left side of the bike. I don't see how it would fit on the Tri-z without either cutting the pipe or doing something to the frame and plastic. I would love to see one that has already been done.

[85ytz250nj]

yea just so i can see how the pipes should look like when its all done

[TimSr]

The 465 has the exact same bottom end geometry as the TriZ motor, and will bolt right into the Z frame. The exhaust is the hard part, and pretty much has to be customized. The 490 motor was basically an upgraded 465 but had difficulties with tuning and stability, which resulted in the 490 actually being inferior to the 465.

[Billy Golightly]

I am not a 100% on this but I believe I read/heard somewhere that the 465 cylinder's exhaust outlet is angled in such a way that you would have to remove part of the frame for the exhaust to go on and that the 490 cylinder was not the same way. This might only be applicable to certain years too...

[85ytz250nj]

so basically if i go with the 490, im getting a less superior motor

if i go with the 465 that i have to chop a part of my frame to make it fit

and if i get the 500 i gotta custom chop and weld stuff.

hmmm.....:wondering i guess which one would be easier now? they are all good motors, of course the 500 will blow the rest out of the water, but how involved is it to install? really i guess the choices are either the 500, or the 465 since i herd that motor was pretty ballsy. any imput from someone with experiance in any of the above swaps?

[deathman53]

I know a yz400, 465, and 490 are a direct fit, I believe the 465 needs the frame rails modified so the angled exhaust clears.

[85ytz250nj]

define modified?

[Bryan Raffa]

84 and up the exaust comes out of the head strait.. the older ones come out at a angle.the yz pipe will not work nore will the triz pipe. they will need to be costom made for the z. All the motors will fit but if you go with a pre 84 frame modify will be nessasary for the exaust port. Im in the middle of building one as we speak so i have done my homework. 84 and up will be the easyst for fabing, just the pipe will have to be built.the carb boot comes out of a angle so you will have to find a strait one, to possibly hook up the air box. Im not running one so im not worrieing about it.

[clutchcargo]

Show us pics when you're done!

[85ytz250nj]

84 and up the exaust comes out of the head strait.. the older ones come out at a angle.the yz pipe will not work nore will the triz pipe. they will need to be costom made for the z. All the motors will fit but if you go with a pre 84 frame modify will be nessasary for the exaust port. Im in the middle of building one as we speak so i have done my homework. 84 and up will be the easyst for fabing, just the pipe will have to be built.the carb boot comes out of a angle so you will have to find a strait one, to possibly hook up the air box. Im not running one so im not worrieing about it.

nice! very helpfull, thank you! anymore info you have or anything you run into give me a heads up.

[Bryan Raffa]

nice! very helpfull, thank you! anymore info you have or anything you run into give me a heads up.

should be A few weeks till i get the frame back from the powder coater but i have everything to put it together rather quick.. Ill let you know!:naughty:

[85ytz250nj]

that thing is goig to be a beast!! i cant wait till im dont gathering information and i can start the building process...good luck on your bike...cant wait to see the pics when its done.

[85ytz250nj]

ok i have decided to do the yz465 in the tri-z frame as of now. but i just bought 3 more trikes. one of which is a 200m. what could i possibly put in that? i dont want something made for speed on this one. of course i want it to have balls, but i mainly want low, and mid range power. i dont feel like messing around with the motor in it now trying to swap parts here and there to get it to run. it is shaft driven so it will be a ground up project, and a switch over to chain driven. my friend suggested the 250r motor, but i kinda like the power band of the tri-z 250 motor. which will work?

[firefirefire90]

hAH. Only chain driven 182cc, 192cc motors will fit. a CRF230 motor will fit also without any mods. NO two stroke motor will fit in it. You can talk to that one boob who says he has a rebel 250 motor in his trike... that might work

[85ytz250nj]

i figured as much. ah i was only kicking around some ideas. i took a futher look at the motor last night and realized that nothing is really wrong with it except for the fact the carb might need work. maybe ill just stick to a rebuild.