400EX ticking? Please help

[tencentsshy]

I have a friend who just rebuilt his 03 400EX its bored .040 over, 11:1 comp., stock cam and everything else. About a month later this ticking noise begins and will not go away. We have checked the valve clearances several times and there is no problem there, put a new timing chain in, and a new chain tensioner, and it still ticks. So he decides he is going to buy another motor, so he buys a rebuilt 426 from a friend. It is a 426 11:1 with an XR400 cam and everything else is stock. He put new clutches in it and started riding. Three weeks later this new motor begins with the same ticking as the original motor. The guy he bought it from says it has new chain, and we switched the tensioners, and checked the valve lash a million times. Can anyone please help me so I can help this kid fix these ticking time bombs. Anything would be of great help. Thanks in advance.

[450Rchaser]

Are you sure you adjusted the valves right.

[tencentsshy]

Yes, I am sure. I adjusted two others plus these two again last night and it still. I have some new findings though. We tore the 426 apart and found the three center cam oil clearance surfaces were scored pretty badly. So I got curious to check the rocker arms as well because there has been a loss of lubrication. He told me that the 426 rocker arm cover and assembly was now on the 416 because the 416 rocker arm cover frame to cover bolt hole broke off so he put the 426 assembly on. So we tore the rocker arm assembly off the 416 which is originally off of the 426 and found the tips of the rocker arms were also scored and were dished out instead of being domed, but the 416 was ticking before the 426 so its not just the 426 that lost lubrication. I have not yet had a chance to check the 416 cam surfaces or rocker arm assembly yet, but he told me the reason for the original rebuild on the 400 was because it locked up. So we seem to have a lubrication problem, plus cheap and crappy oil can't be helping. I am going to check the oil pumps on both motors, the lines, and the tank. And hopefully after we rebuild the 426 I can convince him to stop using cheap wal-mart 10W-30. If anyone has any other ideas please let me know. He is currently ordering parts and we are going to rebuild the 426, and I am going to go completely through the oil system, and hope all goes well. Thanks again.

[TCracin440ex]

sounds like to me your tappets might be bad i know that will make it sound like a ticking time bomb...and ive heard from several people that aftermarket cams do tend to be a little louder then stock..??

[tencentsshy]

The tappets are something I will have to look at really closely and make sure everything is alright. He doesn't have an aftermarket cam in either motor, the 416 is stock, and the 426 has a stock cam out of an XR400. I have heard some people talk about the decompression plunger sticking and making a ticking noise, but he is getting a hotcam this time so we can rule that out if it keeps on ticking. Thanks for helping, I will try and keep you updated.

[lt250rm]

one question are you guys rich. Id be pretty pissed off if i put too motors in my 4wheeler and they both have problems so i just rebuild them. use synthetic amsoil don't use crapy oil and don't use automotive grade oil. If you use regular oil use a no aditive oil from a 4 wheeler dealership it doesn't matter if it says honda or suzuki or yamaha on it as long as it says 10w30 your fine.

[lt250rm]

i would lean towards the oil becuase they specificly tell you not to run an automotive grade oil in 4 wheeler and dirtbike motors (4stroke). Because the anti-wear addatives will cause premature wear and noises that wont happen if you use the right oil or synthetic oil. ESPECIALLY ON A BRAND NEW MOTOR! I use automotive grade oil in my stuff because its cheaper and my stuff is already broken in and my 4 wheelers are 20 years old.

[racemx]

my friend had the same problem but after all it was the carrier bearing in the back. it was so loud that it sounded like the motor.

[jason43050]

sounds like he's got all kinds of money laying around, get a tick in moter toss it and get another, then still tick so rebuild it,then ordering more parts, could of bought a new quad by now lol

[hotrodhonda400]

bad oil pump maybe? I had one in another quad go bad and it sounded like that...

[Rico]

What type of oil are you running?????

[dirtmomma]

OK so our 426ex ticks loud also LOL, it also has an XR400 mc cam in it other than that it's all stock WHAT oil do you guys recommend running???????? We usually run Castrol either 30W or the Castrol Evo 4 stroke oil should be try something different???

[Rico]

SYNTHETIC

You people need to quit using grandpa's snake oil and step up to 2006 standards and go synthetic.

And for those that think synthetic will hurt your motor, well I have some REALLY nice ocean front property here in KY for cheap so call me up...:o

[dirtmomma]

Originally posted by Rico
SYNTHETIC

You people need to quit using grandpa's snake oil and step up to 2006 standards and go synthetic.

And for those that think synthetic will hurt your motor, well I have some REALLY nice ocean front property here in KY for cheap so call me up...:o

LOL OK whats your phone # :D:D:D ;) j/k thanks for the suggestion I will try it & see if it sounds better!!!!!!! We've always run synthetic in our blaster case & it's done good so I see nothing wrong w/ it!!

[96lapis coupe]

Originally posted by Rico
SYNTHETIC

You people need to quit using grandpa's snake oil and step up to 2006 standards and go synthetic.

And for those that think synthetic will hurt your motor, well I have some REALLY nice ocean front property here in KY for cheap so call me up...:o Imagine that, the guy that sells synthetics is telling everyone to use it. LOL!

[Rico]

Originally posted by 96lapis coupe
Imagine that, the guy that sells synthetics is telling everyone to use it. LOL!

I've been preaching synthetics on this site since it started and that was before I started dealing with Amsoil. I"ve probably converted 50 400ex riders on this site to Mobil 1 thru the years and now I"ve found a better oil.

I prefer to use the best types of oil in the industry and leave the crud I mean crude oil to the people of the past.:D

I've got thousands of dollars in my motor as well as many ATV riders. Why put 50 cent oil in a $3,000 motor???? Might as well put a plastic cam in there to save wieght..

[honda460ex]

Snthetic oils are great and I will stand by them, but, if you have a stock clutch that has a decent amount of age on it, count it done. I recomend synthetics under normal circumstances to only be ran if you have an aftermarket clutch with heavier springs. I will say, synthetic has done miracles for my friends KFX400. Had it for going on three years and ran synthetic in it since day one, never replaced a timing chain or tensioner in it one. I have other friends that don't ride theirs as hard as he does and one of them are on their fourth chain and tensioner already. Honestly though, I don't believe you have an oil problem. I'm going with the cam decompressor. They are known to act up and go bad on 400's. Replace the cam with a stage 2 hotcam if you want a major mid to top end power gain and do away with that decompressor before you go through all the trouble of rebuilding a motor.

Good Luck

[Rico]

I ran synthetic with my stock clutch for 2 years and no problems.

It's the best thing a clutch could ask for...LOL

Most companies that make a specific oil for small motors that are air or liquid cooled make them wet clutch compatible. Running an automobile oil that has friction modifiers MIGHT cause a problem but you are running an oil meant for a difference use. But ANY oil spec'd out for ATV or bike use shouldn't have Friction modifiers. At least non of Amsoils do I know that for a fact.

Until recently mobil 1 didn't but they changed the drain interval time on most of their oils and came out with the 15,000 mile advanced formula that everyone now knows as the gold cap and think it came from the devil since it has friction modifiers added to all viscocities. Mobil 1 does offer 2 varieties of synthetics for Bikes.

[Rico]

Also I'm not trying to say that the oil will fix the problem but it will reduce the ticking sound. Cams in 400ex motor's are known to tick, mine does it everytime I fire it up.

[sakirocket28]

yeah, i had the same problem, but after a while of running it on full synthetic, the ticking stopped. I would also suggest checking your valve lash every so often, and check the tensoin on the timing chain, and your cam clearances.