Bmw g450x piston?

[Kusmirlu09]

Hi i am a new member. I have 2009 bmw g450x and is burning oil and i need to hange pistonring and piston. Can i use husqvarna tc449 internals?

[Tims1572]

Yes,
You can use Husky 449 pistons. They are the same.

However, it would be a good idea to disassemble the top end first and have the piston skirt clearance checked and the condition of the Nikasil bore checked before buying the new piston.

There are 3 sizes available. There is an "A" , "B" , and "C" size pistons available from vendors such as "Pro X" etc. They are only fractions of a millimeter larger than each other in size. So you don't want to buy a piston set unless you know for sure which size of "A", "B", or "C" you need.

Other wise you may have a piston too loose for the condition of your cylinders bore.

[Kusmirlu09]

can i joust change the piston ring? or should i change the whole piston?

[Tims1572]

If its got 100 hours or more its time to change it out. If you got it apart. I guess you could just do the rings but I wouldn't recommend it. Since the gaskets are near 1/2 what the Piston kit costs.

BMW/Husky rings may be the only rings that fit the stock piston.

A new piston would have a tighter skirt clearance, isn't fatigued from its hard life and the rings will have a closer end gap and better ring groove tolerances. Which will result in less blow by. Plus the rings from an aftermarket source may be of a Proprietary size, ring gaps different for the A,B & C piston and of a specific thickness as well.

Its all up to you.

You have it apart, I recommend taking the time and doing it right. You will be better off in the long run. The possibility of breaking a piston later on would be very costly.

[Campbell]

can i joust change the piston ring? or should i change the whole piston?

All the info you should need, and follow Tim's advice.

http://g450riders.org/forum/showthre...=1#post1455817

[Tims1572]

Campbell, Thanks again !

I've made this Piston thread a "Sticky", Its a valuable resource of information for all the Forum's members.

Eventually all of us will be needing these important Piston and Top end specifications at some point in time.

So we shouldn't have to dig through all the past threads to find this Piston information out of the Forums long list of topics.

You can all find it near the top of the list with other "Stuck threads" on the G450 Forum Discussion page.

Timmy

[Borain]

i'm new and don't know where to post my question, so here it is. I just put the cams back into the head (g450x) after doing valves and when i swung the motor before putting tappet cover on, it jumped a few teeth and cam timing went out. Is the tensioner the problem? The tensioner doesn't have any ratchet type action.

[Campbell]

i'm new and don't know where to post my question, so here it is. I just put the cams back into the head (g450x) after doing valves and when i swung the motor before putting tappet cover on, it jumped a few teeth and cam timing went out. Is the tensioner the problem? The tensioner doesn't have any ratchet type action.

G'day Ant,
What do you mean by "swung the motor" ? If you have hit the valves with the piston you are taking a big risk on dropping a valve. A slightly bent valve will not necessarily show up with a compression or leak down test. The combination of small diameter valve stems and high seat pressure of performance engines will allow sufficient valve head flex to provide a seat, the same repeated flexing will lead to fatigue. If the piston has contacted the valves it is head off. I have not had a tensioner problem, that said I always prefer an adjustable tensioner. A possible cause of skipped timing chain could be slack on the tension side of the chain, did you have the crank locking screw in during timing?

Campbell

[Borain]

Thanks C, yes i had the crank screw in place. i just turned the motor with the start button and noticed the chain jumped a few teeth. I set cam timing again and :blede: the tensioner in oil, it seems to be holding the tension now. Motor swings and chain is staying timed.
But, got no spark now.

[Borain]

BLED the tensioner in oil, squeezed it closed a few times in a container of oil

[Campbell]

Ant, for future reference use the G450 SERIES DISCUSSION Forum for this sort of post. I would suggest in future once you have timed the cams to turn the engine over by hand with the spark plug out. In gear rear wheel off the ground and rotate slowly in direction of drive. Did the engine lock up?

Cheers and welcome
Campbell

[Borain]

thanks, will do. the motor is turning over perfectly now, just got no spark at moment. i managed to download the cd, it is very comprehensive

[Borain]

sorted, running beautifully, thanks