[250]

Hello everyone, i have read all over the internet looking for answers and seem to get all kinds of mixed answers reading forums about other peoples quads, so decided to enlist some help about my specific situation.

I have a 2013 trx400x that i bought brand new. It burns oil, a lot of it. barely smokes at idle but smokes bad every time i give er gas. I broke the quad in kind of gently, but definitely opened it up a few seconds at a time too. I have on accident used regular gas in it a number of times, which i now know it requires premium. my question is, is it more likely to be the valve seals (which may be because of the fuel) or the oil ring (which might be due to overheating, since i run in the dunes at full throttle for hours at a time)??

Additionally, if i do need a rebuild, ive been told it is just the top end that needs to be done (plus valve seals while im at it). Ive read that changing to a stage 1 hotcam will make a big power difference with little effect on reliability, is this true and would it be good to add it at the same time? I may also add an FMF exhaust and rejet since its a PITA to start.

Thanks everyone for the replies! also, i will be paying my friend to do the work because his dad is an excellent mechanic.

 

[ItsMichaelH]

My guess would be rings. Valve seals would most likely only be smoking when started at an idle, but since its smoking while giving gas, my guess is rings.

 

[SlammedRanger]

My bet is it burned up from the fact they are really lean from the factory to meet emissions. And you ran it in the dunes which is like running it in an oven. On averange you gotta up the main jet by 1 or 2 steps and the pilot i would just go right to a 42. The 42 pilot makes the quad actually start in the cold. And run way smoother. I would honestly also suggest something to add alittle cooling if your running dunes often. Just way way hot for an air cooled engine.

 

[250]

My bet is it burned up from the fact they are really lean from the factory to meet emissions. And you ran it in the dunes which is like running it in an oven. On averange you gotta up the main jet by 1 or 2 steps and the pilot i would just go right to a 42. The 42 pilot makes the quad actually start in the cold. And run way smoother. I would honestly also suggest something to add alittle cooling if your running dunes often. Just way way hot for an air cooled engine.

what exactly do you mean by "adding cooling"? what else can i do to make it run cooler? I was going to increase the jet sizes but was waiting to get a pipe so i can do it all at the same time, maybe i should just rejet now

 

[250]

My guess would be rings. Valve seals would most likely only be smoking when started at an idle, but since its smoking while giving gas, my guess is rings.

hmm so you think it might be worth it to replace the valve seals and see if that fixes it before dropping the cash to rebuild? My brothers quad which is the exact same does the same thing, we ran regular gas in them for basically a year before i read in the manual that it requires premium because for some reason unlike on a snowmobile quads dont print the required octane on the gas cap.

 

[ItsMichaelH]

My guess would be rings. Valve seals would most likely only be smoking when started at an idle, but since its smoking while giving gas, my guess is rings.

hmm so you think it might be worth it to replace the valve seals and see if that fixes it before dropping the cash to rebuild? My brothers quad which is the exact same does the same thing, we ran regular gas in them for basically a year before i read in the manual that it requires premium because for some reason unlike on a snowmobile quads dont print the required octane on the gas cap.

If you want it to stop smoking all together, I would probably just go with a new top end.... I'm sure someone else here has more experience and can drop there 2 cents.

 

[ItsMichaelH]

My bet is it burned up from the fact they are really lean from the factory to meet emissions. And you ran it in the dunes which is like running it in an oven. On averange you gotta up the main jet by 1 or 2 steps and the pilot i would just go right to a 42. The 42 pilot makes the quad actually start in the cold. And run way smoother. I would honestly also suggest something to add alittle cooling if your running dunes often. Just way way hot for an air cooled engine.

what exactly do you mean by "adding cooling"? what else can i do to make it run cooler? I was going to increase the jet sizes but was waiting to get a pipe so i can do it all at the same time, maybe i should just rejet now

You could always run a fan on the oil cooler, also heard the CFM Shrouds help cool the motor some, maybe a larger oil cooler. Rejetting will help alot.

 

[SlammedRanger]

My bet is it burned up from the fact they are really lean from the factory to meet emissions. And you ran it in the dunes which is like running it in an oven. On averange you gotta up the main jet by 1 or 2 steps and the pilot i would just go right to a 42. The 42 pilot makes the quad actually start in the cold. And run way smoother. I would honestly also suggest something to add alittle cooling if your running dunes often. Just way way hot for an air cooled engine.

what exactly do you mean by "adding cooling"? what else can i do to make it run cooler? I was going to increase the jet sizes but was waiting to get a pipe so i can do it all at the same time, maybe i should just rejet now

Well there are lots of option. CFM makes a bigger oil tank(more oil=more cooling), CFM also makes air shrouds that force air into the oil cooler, you can put a fan on the oil cooler, add another oil cooler.

I personally have a 4inch water proof dust proof spal fan on my oil cooler, and air shrouds. And honestly have never been to the dunes. Closest is 8 hours away from me in silverlake MI. I do know personally many people who have gone there and melted there engines down. Seized pistons and all.

 

[UnkleRaRa]

I would think that running the wrong octane level for almost a year would be enough to kill the rings.

Running it hot out in the dunes probably cause a lot of detonation and blew out your rings prematurely.

Be sure to run 91 or higher when fueling.

My guess is rings.

Grab a top end kit, and some cooling mods as mentioned above.

The over sized oil tank I think is the best for cooling as it allows you to carry more oil, and the oil spends less time being cycled through the motor, and has more time to cool down before returning to the crank case.

GL!

 

[XplicitRacing6]

My 400 was also burning oil, running weird, power loss. I am going to do a new top end. I haven't gotten the chance yet to take the head off but I have a thread that I started if you want to take a gander. Its relatively simple to do a top end.

 

[SamUK]

All the above sounds expensive, it is, but remember, you don’t have to do all of those mods straight away.

I would take salmmedrangers advice, rebuild the top end and add a fan. The fan will help for now. Then add the other parts as and when funds allow, bigger oil cooler, bigger oil tank etc.

 

[250]

I would think that running the wrong octane level for almost a year would be enough to kill the rings.

Running it hot out in the dunes probably cause a lot of detonation and blew out your rings prematurely.

Be sure to run 91 or higher when fueling.

My guess is rings.

Grab a top end kit, and some cooling mods as mentioned above.

The over sized oil tank I think is the best for cooling as it allows you to carry more oil, and the oil spends less time being cycled through the motor, and has more time to cool down before returning to the crank case.

GL!

well i only ride 3 weekends a year so not like it had a ton of use in that one year. I think my best option is to pull the head and inspect it to see if its just the valve seals or if it needs new rings as well. I think I will also add a fan, those 4" spal fans seem highly recommended, and possibly add a larger oil tank from CFM, as well as rejetting to keep it a bit cooler. I will likely be opening up the airbox at the same time so i will jet accordingly for that with the main jet and go up to a 42 pilot.

 

[SlammedRanger]

This will give you a good idea if the way i installed mine. Simple and hasnt moved anywhere on me. And i do alot rough trail riding fast. And race a few mx tracks a year.

 

[250]

This will give you a good idea if the way i installed mine. Simple and hasnt moved anywhere on me. And i do alot rough trail riding fast. And race a few mx tracks a year.

Thanks so much! those will definitely help me fab up some brackets

 

[XplicitRacing6]

This will give you a good idea if the way i installed mine. Simple and hasnt moved anywhere on me. And i do alot rough trail riding fast. And race a few mx tracks a year.

Where did you purchase the fan? Do you have a toggle switch to turn it off or on when you need it?

 

[SlammedRanger]

This will give you a good idea if the way i installed mine. Simple and hasnt moved anywhere on me. And i do alot rough trail riding fast. And race a few mx tracks a year.

Thanks so much! those will definitely help me fab up some brackets

No problem glad to help!

 

[SlammedRanger]

This will give you a good idea if the way i installed mine. Simple and hasnt moved anywhere on me. And i do alot rough trail riding fast. And race a few mx tracks a year.

Where did you purchase the fan? Do you have a toggle switch to turn it off or on when you need it?

I purchased the fan directly from spal. The fan itself was about 75.00. But it is fully water proof and dust proof. And has a 5 year replacement warranty. As for the switch i used my factory light switch since i dont have any head lights. With an inline fuse obveously. 5 amp max per spal. And i put an indicator light on my dash so i know if i get crazy and accidentally hit the switch i will see its off.

 

[XplicitRacing6]

Wow a 5 year warranty that's awesome. I have never had a issues with heat on my gray 400. But it also hasn't been rode very hard for very long. Definitely something to look into, thanks for sharing

 

[SlammedRanger]

One thing is for sure. That little 4 inch fan sounds like a jet engine spooling up. I can feel the air coming out the sides if the engine cooling fins about 2 feet on each side. Strong little thing.

PS make sure you get a puller fan. Not a pusher. They sell both. You want to pull the air through the oil cooler as fast as possible. The down fall is yes it blows that hot air right at the engine but honestly i temped it and the air coming out the back of the fan at the engine isnt even warm anymore.

 

[250]

One thing is for sure. That little 4 inch fan sounds like a jet engine spooling up. I can feel the air coming out the sides if the engine cooling fins about 2 feet on each side. Strong little thing.

PS make sure you get a puller fan. Not a pusher. They sell both. You want to pull the air through the oil cooler as fast as possible. The down fall is yes it blows that hot air right at the engine but honestly i temped it and the air coming out the back of the fan at the engine isnt even warm anymore.

yeah thanks i figured it needed to be a puller. i found it online for 60 USD so thats pretty reasonable if it helps that much