Seized up my 450!

[JOYRIDE]

I did not no about the 07 oil mod for the 04 05 06 450s and last year right before winter i seized up the engine and now i dont know what i should do rebuilding wise. I know that i want it to be a true 450 exted of being a 439 but i dont know if i should bore it or put a bigger crank in it or whatever u guys suggest.

i definitly will be putting the 07 oil mod in it that is worth the 200 bucks!

do you race or?

[JOYRIDE]

not really just a few open ridings every once in a while.

idk if you want it faster go with a biger bore or a high comp pistin

the crank will not do much

[JOYRIDE]

12:1 maybe?

umm i dont know much about the piston sizes for a yfz but i would say any bigger you would need to run race gas an its $7.50 a gas

that is the stock piston size on a yfz do you know?

but i do no you dont need the oil mod if you dont ride in the dunes or drag

[leveldrummer]

Originally posted by 450killer265R
but i do no you dont need the oil mod if you dont ride in the dunes or drag

why not? the yfz's have no way of oiling the wrist pin, thats what the oil mod does, so the older models are just running with the hopes that enough oil will splash under the piston to get the job done, i dont see what drags and dunes have to do with it.


i dont believe you can bore the cylinders on these either, you will have to go with a big bore kit that has a new cylinder all together. if you wanna keep it simple you can port and polish the head, go with a slightly higher comp. piston, so you dont need race gas but still get a little speed out of it. i think you can run a 12.5:1 on pump gas, with a 13:1 you might need to mix 50/50, i would check more sources on that though.

[leveldrummer]

i also forgot, while your in there, you can get a new intake cam and just do the exhaust cam mod and it will give you a ton of kick.

cam mod is just retarding the exhaust cam one tooth.

cuz in the dunes oil will not splash or drag un mx or xc it will

[maddmatt02]

when the bikes at BDC does the crank go sloshing through the oil?

[JOYRIDE]

Ya we did the cam mod on it. But i only got like 30 hours on the thing and the guy i bought it from said it was his wifes quad and she rarely rode it besides to silver lake when they would go. We changed the oil regularly and it was running really strong right up until it seized. so if i would have done the oil mod would this have happend?

[JOYRIDE]

o i also notice that some guys r putting WR cranks in there 450 motors. what is that about?

[#17YFZRACER]

if your looking for a true 450 there are a lot of options. one of the least expensive kits comes from hot rods. for the complete kit it is $399.99. its in the motosport catalog.

*for yfz450 04-05
*includes stroker piston and stroker crankshaft
*comes complete with the original hot rods connecting rods, and inner crank shaft webs
*+1.4mm stroke
*piston bore stock(must use YZ450F piston)
*complete and ready for installation

1-866-667-6288




thats straight from the book. never personally used hot rods but havent heard to much bad stuff about em:ermm:

[leveldrummer]

Originally posted by 450killer265R
cuz in the dunes oil will not splash or drag un mx or xc it will

so your saying to dont need a oil mod if you ride trails? your gonna trust your engine to the fact that you bounce around more? the crank is what slings the oil up on the older motors, not the bouncing of the bike.

anyway, its a good idea to do the oil mod regardless of where you ride.

[leveldrummer]

Originally posted by JOYRIDE
so if i would have done the oil mod would this have happend?

no one can really say for sure unless you really dig through the engine and figure out exactly why it failed and what failed first, but it is a very good chance that it would have lasted longer if it would have had the proper oil system.

[JOYRIDE]

thanks for the post everyone and i like the hot rod kit that is 400 dollars becasuse it is cheaper and we would still have to put the 200 dollar oil mod on it so were already talking 600 dollars which isnt that bad compared to what i thought it would be.

[Ride1Rob]

Unless you want to have to rebuild the topend often I'd stay away from a highcomp piston. JE and a couple others only recommend 10 hrs on one of the pistons before it needs to be changed. Anything more than 20hrs and you're pushing it close. The CP's are alil more durable though.

The reason why everyone was going to the WR cranks was because the wrist pen is smaller but has more mass than the stock pens. Many think that because of this it would be stronger but there is also an argument against it. I can't remember what it is but... Myself, I say lubrication is the key regardless of what size it is. I had the WR setup on mine with the HC piston and in 8 months I had 2 piston failures because of so much compression. I was trying to get 40 hrs which is around 6months before my rebuilds. Wasn't working out so I went to the stock 06 setup. I'm actually getting more power to the ground now and accelerating faster.

JoyRide , if you want reliable power go with the port work on the head and maybe bore the carb. Like said before an aftermarket intake cam would give nice power along with the cam mod also. What kind of exhaust are you running on the bike? Also, check your PM's ;) .

[JOYRIDE]

stock pipe with spark arrester takeing out of it but im looking for a curtis sparks system for it.

[250r4life]

Originally posted by 450killer265R
cuz in the dunes oil will not splash or drag un mx or xc it will

what are you talking about?

[#17YFZRACER]

i 2nd that

[JOYRIDE]

He asked me what pipe i am running on it and i told him i have a stock pipe on it but i took the spark arrester out of it and i got better low end cuz there was more air flow threw the pipe. But i put the spark arrester back in when i ride at places that require certain sounds decibels or require a spark arrester.

[maddmatt02]

they arent talking to you, its to that guy whi thinks the oil stays still and doesnt splash at all unless your racing MX or XC

[JOYRIDE]

O ok

[trailwart]

i dont know where your getting the oil mod done at, some only put the squirter in and dont give or recomend the high volume pump. make sure you put the high volume pump in. some places just machine the case and put a squirter in, others machine and put in the yamaha squirter.

[JOYRIDE]

Im sending it to J&T products. I found them off YFZ Central and they sound like they know there stuff.

[Ride1Rob]

J&T is a good guy and does good work. I was one of the 1st to do the upgrade through him. After I tore my motor down a couple of months ago I checked the wrist pen it was nice and lubed. Even underneath the piston was lubed because of the oil mod.

[stic]

Originally posted by 450killer265R
but i do no you dont need the oil mod if you dont ride in the dunes or drag
you actually believe that?