Engine Question.

[BranMan]

I have found an 99 400ex for $900. but it currently does not run. the owner said he was riding at a low speed then it lost power and just quit. any ideas what could have went wrong? if its gunna cost alot to fix i prob dont wanna bother. if any1 has had this happen b4 any help would b great... thanks in advance.

[drew416ex]

Cant really tell without being there, but It may not be engine trouble. IT could be electrical or something like that, or even the carb just got stopped up. Ive never heard of a 400ex blowing up or anything like that at low rpm so I would say its not the engine and if it is I doubt its major. LIke I said though, its kinda hard to tell without being there.

[my88r]

did it run out of gas.lol

sounds like a carb or electrical issue. but for 900 you could use it as a parts bike. i had a parts ex i sold. that i regret now.:grr:

[08400EX]

Always start with the basics. An engine needs air fuel and a spark to work. Of course timing of all the components helps too :-)

Try to start it a few times, pull the spark plug, see if is soaked in gas. If so you are most likely getting fuel. While you have the plug out, blow it dry with air (or use a new one)insert it back into the spark plug boot(not into the engine), touch the tip against the engine case, turn it over and see if you have spark. If not you have an electrical issue.

If you have spark and pretty certain you have fuel, it could be a timing issue. I would start with a simple compression test, this will tell you a lot.

Let us know what you find with these items and we can go from there.

The most common "no start" issue with bikes/ATVs is a fouled spark plug caused by improper jetting etc. IF you are lucky you could put a new spark plug in it and it will fire right up. If so you need to find out why it fouled or it will happen again.

[polish pete]

well i were you id buy it, now and fix it later. who knows it could be a bad plug. i mean if you fix if hes there he might charge you more.

[BigBore24]

sorry to interrupt but 08400ex that thing is sick. very sweet quad. sounds like you guys are on the right track with this thing not starting. worst case scenario could be low compression but even would be well worth the 900 especially if it looks ok

[08400EX]

Originally posted by BigBore24
sorry to interrupt but 08400ex that thing is sick. very sweet quad.

Thank you!

[REPOMAN]

i would also buy it for that price. even if the motor is bad you can get one for under a grand and have a running bike for a damn good price. of course if the the rest of the bike looks good

[BranMan]

Thanks for all the help. i think im gunna go for it. ill let u no how it goes. any more input would still b great.. here is a pic of the bike. its in pretty good shape i think. for a 99 anyway.. let me no what u think

[my88r]

Originally posted by BranMan
Thanks for all the help. i think im gunna go for it. ill let u no how it goes. any more input would still b great.. here is a pic of the bike. its in pretty good shape i think. for a 99 anyway.. let me no what u think

it looks worth 900

for the pic the frame looks good. is all the bearings sound.??

[casey_lamm]

id try to talk him down some seeing how you don't know whats wrong with it...

but I thinnk I would probably do it. It looks good for 900.00 I doubt that its anything major.


Originally posted by BranMan
Thanks for all the help. i think im gunna go for it. ill let u no how it goes. any more input would still b great.. here is a pic of the bike. its in pretty good shape i think. for a 99 anyway.. let me no what u think