Help please

[Daniel wilson]

Hi looking for some advise please I recently purchased an 04 yz 125 and realised the cylinder head is facing the wrong way around  but it's the only way it will go on the the bracket is facing the front instead on the back were it bolts to the frame so I'm guesing the water pipe will be in wrong position too im thinking the cylinder head must be a different year so I'm wanting to know if this will be fine the way it is or effect the bike in anyways please any info will be helpful thanks

[rsmith]

It would help if you posted up some pictures because I am pretty sure you can rotate that head 180° and it will fit so I am curious why it won't

As for your specific question about can you run it like that: kind of. 

From a cooling perspective the hottest part of the engine is in the area of the exhaust port so it is desirable to have the cooler water from the radiator to arrive there first, hence the inlet normally being in that area. So cooling will be compromised somewhat but a lot depends on where and how you ride as to that being important.

The second consideration is the head stay will now not be able to be attached to the frame. It may be surprising to some but the engine is actually a stressed member of the system and not having the head stay connected will affect how much the frame flexes (yes they do flex when you are riding) and can effect the handling. Again much of this depends on how and where you ride.

If you take the head off and post some pictures I will try to figure out why it is the wrong way around.

--Ron.

[Daniel wilson]

I will take the it off for better pics when I get time but i have a couple of pics from Google to show you one is from a 2000 model and the other is 2004

And I don't use it for hours on a track just light use for fun for a couple hours at a time on private land

[Daniel wilson]

The 1st pic was 2000 this one is the 04

[rsmith]

Ah, okay I understand now.

The head stay is in the right spot it is the spigot for the water inlet. In that case never mind taking it off, just refer to my previous statement about cooling inlet location.

If it were me I'd buy a good used head of off ebay and make it right, but I understand about limited budgets as well.

I wouldn't expect you to have an issue unless you ride at a pro level, and even then probably not.

[Daniel wilson]

Thanks for your advise I'm thinking about just buying a used one from ebay when I have some spare cash glad I can still use it for now and not worry as much about it thankyou

[eprovenzano]

I agree...  you can run it without issues, unless you are a Pro level rider like RacerX...  then you'd need to swap it out for the correct one...   

[_X_]

I agree...  you can run it without issues, unless you are a Pro level rider like RacerX...  then you'd need to swap it out for the correct one...   

lol