New Dude - Couple of questions

[SandGeek]

Hello All,

To be honest, I am a die hard 2 stroke rider, been on em since I was 5. My 8 and 5 year old duaghters have taken to riding and I got tired of fouling plugs putting along with them on my 2-stroke so here I am.

I sold the old bike and bought a 400ex. Its got a lot of goodies: 440 kit (11:1), Big Gun exhaust, hi-rev box and some other little odds and ends.

I tore it down and freshened it up. Honed the cyl, new rings, gaskets, adjusted everything.

Its got real good torque but it doesn't have a lot of snap. I know I am never going to get 2-stroke snap, but is there anything I can do to at least make it better?

I have read all the advanced key threads....I know all the 'don't do it on a big bore' warnings, but has anyone ever tried it?

It has the stock carb (jetted of course), I may try some carb swapping. I am a big Lectron fan, anyone use one on a 440?

Thanks in advance for all the help! Please forgive my 4-stroke ignorance.

sg

[represent618]

I say unless you go with a 450R power plant, you will be missing the snap that you have learned to love!

I have been 2 stroke for 20 years also, the snap is not there until you climb on the 450 bikes, they will com unglued on you, but they about as much maintenance as a 2 stroke, if not more....

[SandGeek]

Ya, I know I am not going to get 2-stroke snap. Just looking for a little more. If the answer is "you won't find it, stop looking" then thats ok. It is what it is. Just figured I would ask as like I said, I am just trying to get a feel for the 4-stroke world.

[brian76708]

lighten the flywheel

[represent618]

I personally don`t think the snap will be there with the 400 as a start, now surely some will argue.

you could gear it 1 up in the front to drastically change the delivery, but that bike was not designed to deliver snap.

I have a 450 and really think I should have got a 400, I am tired of the snap when I am trying to play with the kids.

with a budget though, I am stuck with the 450r for a while.

[drew416ex]

A 450 carb and lighter flywheel will help quite a bit. Also what cam do you have in it? I have a nice snap, but nothing like a two stroke, but after about 3000 rpm it pulls extremely hard until redline.

Originally posted by brian76708
lighten the flywheel

yeap there is a ton of power to be gained by lightening the flywheel. Of course you loose some the ability to putt around because the heavier flywheel makes it harder to stall going slow but the flywheel being lightened and if you convert to kickstart which will make it even lighter at the flywheel because more can be taken off but one that did it I think it was a 37% increase in power which is huge.

[Ruby Soho]

the lighter the flywheel is the snappier it becomes. i installed an IRK on my drz110, which turned it from a slow revving 4 poke into a 110 that revs like a 250f. its flywheel is maybe 2 inches now..

ill get a vid of it soon to show you the difference.

[AZ440ex]

Originally posted by SandGeek
Ya, I know I am not going to get 2-stroke snap. Just looking for a little more. If the answer is "you won't find it, stop looking" then thats ok. It is what it is. Just figured I would ask as like I said, I am just trying to get a feel for the 4-stroke world.

Nothing quite like a 250 two stroke.
I run a similar set up. 440 big bore, hot cams stage 2, big gun rev box and exhaust. It is never going to be an TRX250R. I also have a 450r bike and it is still not snappy like my old CR250 bike but pulls like a train from 1,000-9,000 RPM's.

Do you have a cam? What stage? I would suggest a stage two for all around power. Gearing might help you out with the "Snap" I run one tooth smaller on the front when I ride mx and it has pleanty of pull. If your looking for fast rev's "on the pipe feel" I think the others are right about a lightened flywheel, it's going to help.

I think it's just a feel you will have to get used to and probably will end up a faster rider on but I understand there is nothing like hitting the powerband on a two stroke, it still brings a smile to my face.

[SandGeek]

Ya, it has a stage 2 cam. I think your right about just having to get used to it. My ride for the last several years has been an '88 Kawasaki Tecate with a ported 310 and all the trimmings. Fun but certainly not kid friendly. I think I will get used to this bike and have a lot of fun with it.

Thanks for all the input!

sg

[leasureryan]

if you are going to lighten the flywheel....why not just do the XR 400 kick start conversion, dump like 2 lbs off your flywheel, (much more than if you just lighten the 400 fly wheel)

I here it makes a world of differance

thats not all though. Does it have EVERYTHING done to it??? If not....finish up where the previous owner left off.

[SandGeek]

Originally posted by leasureryan
Does it have EVERYTHING done to it??? If not....finish up where the previous owner left off.

I think so....440 (89mm 11:1 piston), stage 2 cam, Big Gun exhaust and Rev box. I pulled it apart to freshen it up with a hone job and new rings. The inside looks like the jetting is correct.

Am I missing anything?

Thanks
sg

[AZ440ex]

Kick start is NOT Kid friendly.
Sounds like most is done, port job maybe, valves, thin head gasket to boost compression a bit, I ported my stock carb, remove the choke, (lots of people on here run a 450 carb). Next rebuild you could go high compression with HD head studs.

You could dyno tune it to get every last bit out of the jetting, it usually gets a little bit more power out of it.

[Ruby Soho]

Originally posted by Ruby Soho
the lighter the flywheel is the snappier it becomes. i installed an IRK on my drz110, which turned it from a slow revving 4 poke into a 110 that revs like a 250f. its flywheel is maybe 2 inches now..

ill get a vid of it soon to show you the difference.

here. lightening the flywheel will do the same as this

before

http://www.youtube.com/watch?v=4PaejFVP66U

after

http://www.youtube.com/watch?v=Fkdr0OaUuS0

[leasureryan]

what?????.......run?

I don't see the differance...lol

[Ruby Soho]

listen how much faster it revs up and down.

the first one isnt such a good example cause i already took 3 pounds off the stock crank, i had an old video of it running with everything stock besides the exhaust. but its alot more noticable in person

[SandGeek]

By 'Kid Friendly' I ment that I can ride with them, not let them ride it. They have their own bikes. A pair of E-Tons (50 and a 90).

I could not go their speed on my 2 stroke without falling plugs. So I sold it and bought the more versital 400. I want to be able to putt beside them without issue and yet go out and rail with my buddies when the kids are at camp.

To be honest, I have only had the 400 out in the uncles field and it was having head gasket issues. I have the new head gasket, the cylinder is honed and I am just waiting on the rings which are in route.

I may take it out for the first time and fall in love....Mostly this thread is me being nervous about the switch and finding out what my options are if I take it out and it sucks. :p

Sounds like I have options....lighter flywheel, 12.5:1 piston, better carb. None of this may even be needed....but its nice to know its there.

Thanks again
sg

[Ruby Soho]

install HD studs.

[krt400ex]

Originally posted by brian76708
lighten the flywheel


put a non-oring chaine on there, helps alot. also a 450R carb will do wonders

[leasureryan]

yeah the carb does help


use a xr 400 head gasket, it's thinner, and trues your compression up

[AZ440ex]

If you already had a bad head gasket it might be time to put in HD head studs, the previous owner might have run it hard or on cheap fuel and streached them. You might get away with just a new gasket and TQ them correctly but once people start poping gaskets its usually time for new studs or helicoils. Its really the threads the stud mounts in that streatch.

I still run stock studs but from what I have read I am one of the lucky ones.

I think they are 65 bucks from GT Thunder, since you already have it apart it is probably worth it, especially if you ever bump up compression. They are almost a must with 12.5:1

[coryatver]

I have never seen any 400ex that someone has put a kickstarter on it. I have seen some that people have put the xr400 motor in it but I think it is pretty much impossible with 400ex cases and internals.

[leasureryan]

not impossible. All you need is both side case cover, the fly wheel, and a couple gears for the tranny. It gets done....trust me!

[krt400ex]

Originally posted by leasureryan
not impossible. All you need is both side case cover, the fly wheel, and a couple gears for the tranny. It gets done....trust me!


how expensive would it be? im interested in it now.

[drew416ex]

Just remember, to get the full benefit of the kickstart, you have to get the xr crank also. Its narrower than the ex.