So my xmas just went down hill my MX bike seized solid

[Aaron_]

3 laps in and my 14 YZ450 seized just pulled the top end off and the big end is seized and the piston don't look to great looks to me like oil starvation any bikers out there that know a lot about them

 

[Woody.v8]

Ive rebuilt mine 15 times or so, What do you need to know?

 

[Aaron_]

just any idea why it would do that just seams very unlikely the oil pump would pack up, will pull the engine out and have a better look in the week

 

[Woody.v8]

It sounds like oil pump or knackered big ends bearings, Has it been serviced regular?

 

[Aaron_]

Yeah mate oil changed every 3 rides only done a top end rebuild 25hrs ago

 

[Woody.v8]

Eerm... This engine needs a total strip and inspect every 12.5 hours!

 

[Aaron_]

Eerm... This engine needs a total strip and inspect every 12.5 hours!

Do you not think that's abit OTT I don't trash it don't really race should get 50hr easy and it's not like you can check the big end easy. Or I've been going very wrong lol

 

[Woody.v8]

Do you not think that's abit OTT I don't trash it don't really race should get 50hr easy and it's not like you can check the big end easy

I know what your saying, but its a race bike and they are what yamaha spec for rebuild, Some get away with it, some don't.

 

[Aaron_]

True. Just need to pull it apart and see I guess really hope the crank it ok going to have to tell the misses her presents are going to have to go back to fund it lol

 

[Woody.v8]

True. Just need to pull it apart and see I guess really hope the crank it ok going to have to tell the misses her presents are going to have to go back to fund it lol

Just give me a shout if you need any help, How to's or sizes etc

 

[Aaron_]

Will do mate cheers I appreciate it

 

[ronan]

Eerm... This engine needs a total strip and inspect every 12.5 hours!

, i had a yz125 back in the 80's and it was never rebuilt.

 

[Woody.v8]

, i had a yz125 back in the 80's and it was never rebuilt.

I have had bikes and ive thrashed the ring out of the and they have been OK, Others not so, Especially when racing.

 

[Robotstar5]

Eerm... This engine needs a total strip and inspect every 12.5 hours!

A workmate was looking for a YZF last and I couldn't believe how high maintenance they were.

 

[ronan]

Yeah, 12.5 hours seems mad. The piston rings must be wafer thin on them or something.

 

[Woody.v8]

A workmate was looking for a YZF last and I couldn't believe how high maintenance they were.

People think this and put supermoto wheels on them, What's the worst that could happen?

 

[Woody.v8]

Yeah, 12.5 hours seems mad. The piston rings must be wafer thin on them or something.

It's not that so much but it's the power they get out of them and how quick they rev! Also they have 5 titanium valves!

 

[pondy]

Raced my yfz450 for many years, really need to keep on top of them, money wasn't really an issue to every 15 hours it got a new piston, could do them very easily in the end. if you want a bike for messing about at the weekends this isn't the engine for that.

Mine did go bang once

 

[Aaron_]

I have no problem doing the piston ever 15hr now I know it really needs to be kept on top of how often do you do bottom end work on it

 

[Woody.v8]

Yam say inspection of crank every 12.5 hours