help! blown head gasket?

[trxPOWER]

hey guys, i really need some help here. So i was driving home on the roads, and decided to see what my wheeler could do. I had it pinned in 5th for about 5 seconds when the wheeler started to loose power and run loud and crappy. i nursed it home. when i got home i found that there was oil on the motor that looks like it was comming from the head gasket? also the motor is REALLY noisy, sounds like in the head? please, can somebody tell me what they think happened?

also, if it needs a topend, do you think its doable by myself? what tools would i need to buy to do a whole top end? thanks guys!

[250rforlife]

ok i had the same problem. its defintally a head gasket. does it sound like a suqeeky noise when you get on the gas? myn did. and if its leakin oil from the head area then its defintaly it. but ull defintally need to take it apart. tools? i sugest wratchet, 8-18mm socket, 11-15mm wrenchs, allen wrenches, 3mm-10mm, torge wrench, owners manual, phillips screw driver and flat head,5lb sledge an a chisle.(never no). and last a feeler gauge. thats about it. good luck

[CJM]

Before you do anything else, you need to test the compression. Get a gauge, remove the plug and crank 5 seconds with the kill switch off. If it doesnt read at least 100 psi yes the HG is bad

[trxPOWER]

heres some bad pictures http://i778.photobucket.com/albums/yy63/rotexPOWER/101_4271.jpg http://i778.photobucket.com/albums/yy63/rotexPOWER/101_4270.jpg http://i778.photobucket.com/albums/yy63/rotexPOWER/101_4269.jpg http://i778.photobucket.com/albums/yy63/rotexPOWER/101_4268.jpg

[trxPOWER]

is the head gasket a common thing to fail? or dose it sound like i might not be dealing with a stock motor here?

[IMSROLL450R]

A head gasket is a 2 hour install tops with a manual and the right tool which have already been listed. Get one from Cometic and get it installed.

[CJM]

Proper torque is KEY! 33ft-lbs on each head nut. The valve cover bolts get 7ft-lbs, DO NOT OVER TIGHTEN THEM!

[2001400exrida]

whoops, i went to 13 on my valve cover bolts haha, one of mine was stripped out but it would still thread it just wouldn't tighten so i took lock tight and got it in there as tight as i could. we will see after some good riding if my head cover gasket holds.

[CJM]

Originally posted by 2001400exrida
whoops, i went to 13 on my valve cover bolts haha, one of mine was stripped out but it would still thread it just wouldn't tighten so i took lock tight and got it in there as tight as i could. we will see after some good riding if my head cover gasket holds.

Would be best to either tap it for a 1/4 bolt or a 7mm allen head bolt (fits better) you can get everything at home depot.

Some of the bolts dont go down very much either, just into the head and some go all the way into the cyl if I recall.

[2001400exrida]

yeah this is where my valve cover was leaking before i did the rebuild.

It's one of the long bolts that goes down to the cylinder. the good thing is, i've done my break in and it hasn't leaked a drop so i may have the ones around it holding well enough and i might have it deep enough in the threads to hang on by the locktite.

If it start leaking i'll have ot figure something out but for now it seems to be holding just fine, we will see after a long day.

[CJM]

Good luck with it, hope it dont leak!

[trxPOWER]

hey guys is there anything else i should replace when i tear down the top end?

[CJM]

Cam chain, tensioner and guides if they are worn. Use a honda CRF450 2002 cam chain, its stronger and cheaper.

[trxPOWER]

what book is beter, the honda service one or the cylmer one?

[CJM]

Honda manual imho. Even so clymers nice to have. Honda manual can be found online for free if you search for it.

Its not really that hard to break down and rebuild the top ends of these engines imho.

[400exshop]

The cylmer one is junk. Also if it is not stock and ( if ) it is a high compression motor then get your cylender O-ring it will not leak again. I had mind done and it's a 13.2.1 on nos. 12.5.1 piston and my cylender is decked 0.25 puts it at like 13.2.1. hope this help's you.