blew up my 400

[bigbad400]

:mad: so i was riding over to a friends house a couple miles away and everything was running fine and i came over a rise in the road and throttled up to wheelie and i heard a terrible grinding comming from the valves it shut the motor down and slid me right to a stop even with the clutch pulled in. i havent tore into it yet but im pretty sure it broke a valve and lodged it into my piston and ruined my whole motor:( i thaught i was gonna cry yesterday...

fortunatly i have another motor and i was in the prosess of building it to a 426 ill just have to hurry that along and get the thing running so i can ride again. i bean working on it slow cause i bean riding so much lately now im kinda forced to just do it.

but since i have a need to know what happened being a weirdo like that, i will be ripping into the motor to see what the f@#$ happened to my baby. something in the topend let loose in a real hurry, no warning noises or nothing. i will post up pictures of the carnage when i get to it.

she WILL run again!!!

[Snipe]

That sucks man. Had something like that happen to me once. First bike i ever owned was a yamaha blaster it sent me to a stand still. Rod broke on it.

[offroadhonda]

It doesnt sound like the motor if the clutch didnt work. Id break open the trans.

[bigbad400]

ya know you got a good point, but the sounds i heard lead me to believe its the valves, if its in the trans ill be rebuilding the whole thing anyways.


last night i remembered a time last summer i was at silver lake dunes and i went throught a water hole that was too deep and stalled out and whatnot, water flowed in through the exhaust not at all the intake, so i figured it was ok. it started up ok after the water spurted out the exhaust, so im assuming i bent a valve then and it just let loose the other day.

[bigbad400]

mass desruction!!!

[bigbad400]

3 of 4 valves broke

[bigbad400]

good thing it didnt hurt the piston any lol

[bigbad400]

that goes there right?

lmao. Well... all in all... at least you have an excuse for high compression and a new ported head:devil:

[bigbad400]

since my ol' lady left me and moved 200 miles away i had alot of free time, but me and my dog stay true till the end.... my little garage helper. (she steals wood from the wood pile and peals bark off it and puts it back!!! weirdo!)

her name is Chevy Lynn and shes pitbull boxer mix about 3 years old. my 16 month old baby climbs on her and pulls her tail and she dont even look at her hardly. great dog and best friend.


so what do you all think of the 400 motor now? id say that chit will buff out right?


man its a good thing i found a great deal on parts again i couldnt afford to have a 440 without a deal like this one.

i really want a 426 but i got such a good deal on a ported 440 head with kibblewhite valves and springs and 11:1 piston with the gt thunder hd studs installed and all for a very low price... like i could buy a 426 piston and rings for what im paying for this stuff. its never even bean installed. i couldnt turn it down.:eek2:

[bigbad400]

Originally posted by DMC-4OOEX
lmao. Well... all in all... at least you have an excuse for high compression and a new ported head:devil:


some say the 400 responds well to the sparks key, i say it was a little too advanced for my application, had i known how to judge that befor i would have removed it befor this happened. i thaught i bent a valve but everyone seems to think it was valve float because of too much advancement, she didnt sound like it was off at all it ran perfect no pinging but it did tick like all these darn 400s do... i did the valves and the cam chain and tensioner like 4 months ago.... woops should have upgraded to kibblewhite then when i put the hd cam chain in.

maybe the 3 or 4 degree key will work better. i need to learn what to listen for if its not right.

[Honda#4]

I'd say thats the worst destruction i've ever seen on a 400 motor, but what a relief that you have a backup motor otherwise I would have been cryin for sure.

[bigbad400]

im not even getting in to the back up motor.... id like to keep that an extra now that i got such deal on the 440 stff im gonna fix this one.

2 bore projects all at once 440 and 426 lets see how i do?

[Honda#4]

All in all have fun doing it.

[bigbad400]

oh ill have fun.. id almost rather be tinkering in the garage with my wheelers and toys than riding them sometimes, i spend alot of time out there.