99 WR400f trouble starting

[ffd480]

I am new to the riding world and have a 99 wr 400. I am having trouble starting the bike. I have been told there is a new cam that can be swapped to fix the problem. I am looking for the part number and to hear about any experiences with the problem and fix. I am thinking of selling the bike for one with an E start if I cant fix the problem, but the bike runs and rides great once it is started. Any help is appreciated. Thanks.

Lupe

[Fullbore4]

Once you get the knack of starting that bike, it will be much easier. E-start is nice as long as it works. I have an 06 wr450 but the starter is not real heavy duty. Lots on here have had trouble prematurely.

[Bamster]

Is it just the starting drill you are having problems with?

cold

(1) choke out

(2) Kick slowly down until the lever becomes hard to push (top dead center)

(3) Take foot off of kick lever (bring to top)

(4) Pull in compression release and nudge kick lever a hair past hard spot (top dead center.) then let kick lever come back to the top.

(5) My 400 likes 2 to 3 twist of throttle (this may vary)

(6) Remove hand from throttle and place on front brake cylinder as not to inadvertently give throttle while kicking.

(6) Kick firmly down through full kick range

Repeat if needed.

When bike is warm no throttle twists or choke are needed.

If you stall or drop the bike the hot start may be required.

If you still have a problem check your valves as they may be tight.

I have also seen where an idle set too high can hinder starting.

You really should have no problem starting the 400 when done corectly

but don't try to start it with running shoes on as it does require a good firm kick. I have never had a problem starting my 400 when I'm wear my MX boots.

[JDrooster]

My 99 400 starts just the same as Bamsters. Once you know the drill it's really easy to get started. The cam upgrade you're referring to replaces the stock exhaust cam with an 03 model wr or yz cam and eliminates the compression release altogether. You can use an aftermarket exhaust cam as well (hotcams). Do a search on "exhaust cam" and the part number is out there. there is even a very good tutorial out there somewhere that will guide you through the replacement (I believe it's on thumperfaq). No starting drill required after the cam swap. Give Bamsters drill a try. It's normally foolproof.

[SXP]

I am new to the riding world and have a 99 wr 400. I am having trouble starting the bike. I have been told there is a new cam that can be swapped to fix the problem. I am looking for the part number and to hear about any experiences with the problem and fix. I am thinking of selling the bike for one with an E start if I cant fix the problem, but the bike runs and rides great once it is started. Any help is appreciated. Thanks.

Lupe

All good points above. However, the decompression cam from the 03 and later YZ/WRs eliminates this drill and also reduces stalling ,and allows bump starting the bike. A must do in my opinion.

If you are local, I would be happy to walk you through the cam installation procedure. The YZ decompression cam is about $100 and the WR about $150 (not sure why there should be such a difference in price).

[ffd480]

Thanks for the information. Does anyone know the part number for the cam, or which bike it comes out of. I believe it is supposed to come out an 03 YZ 450, or WR 450 but I need to be sure before I spend the money. Thanks for the help.

[SXP]

Thanks for the information. Does anyone know the part number for the cam, or which bike it comes out of. I believe it is supposed to come out an 03 YZ 450, or WR 450 but I need to be sure before I spend the money. Thanks for the help.

Shouldn't matter, but for your peace of mind I have the 03 YZ450 exhaust cam in one WR400, and the 03 WR450 exhaust cam in the other.

[ncampion]

One other thing to mention is that you must have your carb in good shape. It's worth it to tear it down and make sure there's no crap built up in any of the passages or jets. This also assumes that you have it jetted correctly in the first place.

[1rkcooper]

Her is the link to the cam mod. I have the cam and plug but have not installed them yet, two feet of snow here so no need to yet.

https://www.thumpertalk.com/forum/showthread.php?p=3706078#post3706078

[ffd480]

Did you guys need to adjust your valves when you were finished? Or is it a straight bolt in swap? Thanks

[BOULMAN]

I have had a wr400 and now a wr426. Correct jetting is EVERYHING. My buddy had a wr400 wouldn't start without giving up your right leg. We rejetted it and it started like a champ. Yes there is is technique to starting, but you have to have it setup right to give yourself a chance. I have not changed cams yet(too cheap)

JD jetting made the process really easy, although I still had to change the pilot jet and add a fuel screw.

FYI if it is jetted correctly it will need the hot start if you shut it off (once warmed up) and try to restart right away. If it doesn't you are probably too lean in the idle circuit.

jb

[redrocket190]

I have a 1999 WR400F with a JD jetting kit and all the emissions equipment etc. removed. You prime it with 3-5 gentle kicks and then use the decompression lever to get it just past TDC. Then one big kick from the top and it starts. I have an IMS Hot Cam with auto-decompression ready to be installed.

[standup rider]

I to have a 99 WR400 and it starts on the 2 or 3rd kick. I have gone thru my carb and installed a JD jetting kit. Just need to get my AP (accelerator pump) working as you should veriify that yours is working correctly also. The AP effects your initial throttle responce.

As has already been said , if your carb isn't set up right then it will not start well. I think you are wasting your money buying a cam to correct a starting problem. Listen to what the guy's on this web sight have to say. They know from experience. Good luck.