Need help with my 440EX

[Tyler 54]

So I just bought this quad. took it home and put a timing chain it. It runs Awesome but smokes a bit. So I tore it apart to find it has a JE 440 Kit in it. Now the questions.

I had the cylinder checked out and I should be able to re ring it. When it was warm it was blowing black smoke, that means rich right?

So the engine/exhaust is bone stock other than this kit. Stock carb with a 159 Main. How do I find out what compression the piston is?

Also was reading on here about E-Fan and exra oil coolers.
Would a bigger oil cooler be just as good as an "extra". Any suggestions on the E-Fan? I do trail ride alot.

Also looking at the Curtis sparks Exhaust. Is the sparks with the Cash? I had one on a bike before and it Really sounded nice. Or would a good slip on Do the job?

Now as far as a cam, Hot cams stage 2 looks pretty good, along with some mild port work. I'm guessing I need to know what compression I am running to make a good Camshaft choce.

I want to keep this thing reliable, and be able to ride tight trails.

[mitchconley]

why all the mods if youre just trail riding? a slip on pipe and new filter do me just fine for trail riding

[Tyler 54]

I know this. I just sold my 04 with a slip on. It was bone stock with the slip on and I loved it.

This bike wasnt supposed to have the 440 kit in it, now that i see it does I'm thinking just go with it.

My other firends are running 416 kits and talking alot of smack, so if I can build a better motor, do a small bit of my own head work, and smoke them on the trails. I'm happy. I'm off work with a broken ankle for 2 months so I have plenty of time to build it.


Also seeing the XR400 Head gasket looks like a good thing. Can I get one to fit the 440?

[250x_kyle]

black smoke doesn mean that its rich. just that your getting blow by. piston rings should fix that. as far as pipes go curtis sparks are worth it in my opinion. better flow then stock by a long shot. the color of the spark plug will tell you wether your jetting is rich lean or spot on.

if your going to cam it new valves is a good idea. port work isnt gunna be cheap either.

[tri5ron]

with the 440 piston in it, you probably are at a 11:1, or 12:1 compression ratio. That seems to be what most guys do when they go to the 440 piston.

But,... What most of them fail to do, WHEN putting in the 440 piston is, they dont put out the extra cash to have the HD headstuds installed.

The 400ex is a GREAT trail/woods quad. nearly bulletproof.
but it does have a common problem when going to the 440 high compression piston.
That problem is,... It likes to pull the stock, OEM, head studs right out of the cylinder.

Sure, there are plenty of guys here that will tell you they have been running it without the HD headstuds, with no problems.
But there are AT LEAST as many here that will tell you the horror stories of putting in the big 440 11:1/12:1, only to quickly discover a blown head gasket/oil leaking. then they come to the unfortunate realization that it's not just the blown head gasket, but in fact it's a junked cylinder due to the head studs yanked out of the threads.

I have yet to hear of anyone, who has yanked the HD studs out of the cylinder, and I also dont know of anyone who has yanked the OEM studs out of a stock 400cc.
So what's that tell me ?,....

It tells me that if you are going to run a 440, higher compression piston, it is safer, cheaper, and more reliable in the long run to spend the extra cash for the HD studs.

Also a thing for you to consider ,(as you already have been doing), is that the 440 creates more heat due to the higher compression, and thinner cylinder walls.
You mentioned the intrest in bigger oil cooler and fans.

That's a good idea, ESPECIALLY in light of your intentions to use this as a trail bike on tight trails.
That means that you will be riding at slower speeds often, and therefore not having as muck airflow for cooling as you would if you were riding at higher speeds.

so in summary, (and just my opinion),

A 440, high compression, being used at slower speeds, in tight trails, creating alot of heat, then going full throttle to slap your buddies around, is definately in need of the HD studs.

or you ccould, NOT spend that extra cash on insurance, reliability, and peace of mind, and simply take your chances. maybe you'll be one of the lucky ones, and it dosent blow,...
BUT,
If your NOT one of the lucky ones, then you'll soon be looking for a replacement cylinder, AND the HD studs too.

Do yourself a favor, and do a search on HD studs.
Read up on what alot of people have to say about it.
Then you will be able to make your own informed decision, on wheather it is a worthwhile precaution, of simply a waste of money.

I'm not trying to be a smartazz here, I just thought that since you are fairly new to the forum,... that you may not be aware of this common problem, with putting in the 440, high compression setup, in a 400ex.

Hope this helps, and Welcome to the Forum.
Ride Hard, Ride Safe, and Keep the rubber side down.

- Ron

[Tyler 54]

I have read up on these studs. Seems like the name GT thunder comes up alot? Who is Gt thunder? Somebody have a link to were I can by these studs? I can't seem to find them.

My other thought was see how I like the 440, if I do like then install the studs down the road. I have some extra cylinders if something does happen. However its seeming like a smart thing to just do, and be done with.

Thoughts on the oil cooler? One big one with the Spal electric Fan? or go with two and use the Four stroke Tech style?

I thought one big one with the Spal fan would be good enough?

Tyler

[togup]

JE makes a 10.8.1 would be more "reliable" and suited for trail riding have your jug checked and honed while your at the machine shop put in head studs and as far as xr gaskets cometic has them and can make any custom gasket by the way.

[dagger350]

Gt thunder website is http://www.gtthunder.com/

[wrekd]

Originally posted by Tyler 54
I have read up on these studs. Seems like the name GT thunder comes up alot? Who is Gt thunder? Somebody have a link to were I can by these studs? I can't seem to find them.

My other thought was see how I like the 440, if I do like then install the studs down the road. I have some extra cylinders if something does happen. However its seeming like a smart thing to just do, and be done with.

Thoughts on the oil cooler? One big one with the Spal electric Fan? or go with two and use the Four stroke Tech style?

I thought one big one with the Spal fan would be good enough?

Tyler


You'll like the 440. When done right they are reliable and pretty darn quick. DEFINITELY do the GT Thunder HD Studs!! I had a 12.5:1 440 kit and I blew a head gasket on mine. Luckily nothing else got damaged. I think it cost me about $120 to have GT Thunder install them. Not a problem after that. I would go with a Stage 3 hotcam. I had a stage 2 and it was good, but I think the Stage 3 would be better. Plus the port work would compliment it nice. Definitely get a full exhaust. The stock headpipe just doesn't flow enough for a 440. For cooling, I was alright with the stock cooler with a SPAL 4" fan. The FST cooler wouldn't hurt though. Jetting plays a big part in heat though too. So make sure its jetted right. I think I ended up with a 45 pilot and 168 main.

[Tyler 54]

Thanks for the opinions. I'll be calling Gt thunder tomorrow, I can install those studs, I have access to a drill press so it looks pretty easy. Can the Studs be removed out of the cylinder once installed? I only ask because if this 440 doesnt work out, I'll take it out and punch one of my extra cylinders to a 406, and just use it.

Whats going to be the better buy right now? My funds are limited.

Should I buy the Camshaft and Spal fan? then wait on the xhaust.

Or buy the Exhaust, then spal fan and Camshaft.

I think I decided on the Sparks X-6. Seems to me buy the exhaust last so that I can get this back together and be waiting on fund for the Exhaust.

I just hate to spend that much on a pipe, when a slip on is a fraction of the cost.

[06typeS]

I would call GT thunder and talk to them about what you would like to do and what your expecting to get out of the motor and the type of riding you do and let them guide you.

I would def do the headstuds up front, no point in getting the motor together and then ripping it apart to get studs put in.

No offense to anyone here but everyone has their own opinions, and not that their wrong just some have different idea's then others.

To me i wouldn't worry about the cam to much and focus more on reliability, a fast quad is fun but if you can't ride it then it doesn't make much sense.

best of luck

[wrekd]

Go with the exhaust 1st.

[Tyler 54]

picked up a four stroke tech add on cooler from a friend.

Which oil cooler would benefit more with the electric fan?