fed up with the old 4 hunny

[underpowered]

been a while fella's.


the good old 4 hundred has held together pretty well over the years. but as of late, it has been one thing after another, and i think it finally bit the big one.

i just replaced the valve seals due to a bad smoking issue. worked great, no more smoke! but after the valve seals it had a bad knock to it. no idea what it is/was but i know it was not there before i did the valve seals. sounded like it came from the bottom end of the motor, which i have not touched in 2 years.

started it up today, it ran but would only idle. as soon as you hit the throttle it would die. knock was still present, i was only starting it to check the oil properly. oil looked fine, started it again to pull it in the garage, and finally got some throttle out of it. all teh suddend it made a bad noice (clanking scraping noise) and now it won't even turn over. locked up tighter than a drum.

what to do now? sell it for parts? replace motor? rebuild time? or hybrid? all are options i am currently considering, with hybrid in the lead. gonna tear it down next week to see what exactly when wrong. current speculation says timing chain went south, even though it is only about a year old.

[fastredrider44]

Part out anything that is good on the motor. You can get decent 400 motors all day long. or make a hybrid, they're just cool, or part the whole thing out, and get another. Depends on how much you like the thing.

[underpowered]

well it has been forsale off and on for the past year or so. but everytime i ride it i want to keep it. i love it but don't ride much at all. i have only kept it since it does not cost anything to sit there really. i start it up and go around the yard once in a while, but only actually ride 3-4 times a year. if i sold it/parted it out i would most likely not get another one.

i love to ride so i want to fix it, but if i sold it i could use the money elsewhere also. quite a dillema.

[REPOMAN]

mine did the same noise recently and i am now the proud owner of a 450r. timing jumped or was off and slapped two valves making a nice peep hole in the piston.

[underpowered]

Originally posted by REPOMAN
mine did the same noise recently and i am now the proud owner of a 450r. timing jumped or was off and slapped two valves making a nice peep hole in the piston.

thats what i am thinking it is.

if that is all, i will most likely fix and keep it. a piston and valves are cheap to fix. all said and done for under $150

[250x_kyle]

build a hybrid you cant go wrong. im selling my hybrid motor if your interested.

[underpowered]

Originally posted by 250x_kyle
build a hybrid you cant go wrong. im selling my hybrid motor if your interested.

if i go hybrid, i want to do something different. not sure yet, maybe a 250f hybrid.

[AZ440ex]

Originally posted by underpowered
if i go hybrid, i want to do something different. not sure yet, maybe a 250f hybrid.

Only problem with a 250f is they are pretty maintanece intensive. They have more valve issues than the 450's

[Duke Nukem]

Originally posted by AZ440ex
Only problem with a 250f is they are pretty maintanece intensive. They have more valve issues than the 450's

Thats because you have to rev those 250's to the moon, to get the best power out of them anyway. From all that revving, the valves hammer in the seats and they constantly lose clearance.

[krt400ex]

Originally posted by underpowered
if i go hybrid, i want to do something different. not sure yet, maybe a 250f hybrid.


i have always wanted to put a yz134 in mine...or a ktm 150sx. that to me would be pretty cool

[underpowered]

Originally posted by Duke Nukem
Thats because you have to rev those 250's to the moon, to get the best power out of them anyway. From all that revving, the valves hammer in the seats and they constantly lose clearance.

exactly. the valves open and close so fast that they wear excessively.

i think a small 2 smoke would not have enough power. even teh ktm 144 would not have enough balls to hall me around.

[400exrider707]

Just rebuild teh 400ex motor.

I'm usually happy when something happens to my motors, gives me an excuse to make it faster!

[Hondamaster5505]

I smell XR650L motor..:cool:

It would look just like the 400ex motor, but a LOT more torque. The 650 engine isn't too much more horsepower, but it's the torque where it shines.

When uncorked, they're capable of a lot of power too.

It's funny how they look almost identical from a small distance, so people wouldn't know whats underneath you:blah:

[underpowered]

Originally posted by 400exrider707
Just rebuild teh 400ex motor.

I'm usually happy when something happens to my motors, gives me an excuse to make it faster!

i used to be, but now i have the quad just to have it. it has been over 2 years since any mods on it.

i have to many other things to dump money into, like my Jeep or my truck. most of my money is currently going into my jeep as atoy and teh quad is 3rd rate now.

i will tear down and see how bad it is then make a call. if it is exptensive i will most likely sell it. if it is not to bad i am gonna fix and keep it.