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View Full Version : ltz400 wont start



fnmracing
02-16-2009, 09:29 AM
i need some help or ideas on what to check. my wife bought me a 03 ltz 400 they delivered it about 8pm it started i drove it down the road and parked it. i cannot get it to start again. i have changed plug 3 times pulled carb apart checked and cleaned it. what should the jet be for this quad. all it has is a white brothers slip on. it had a dyno jet 140 in it

smw450r
02-24-2009, 07:09 PM
is it getting gas and is it getting fire?

fnmracing
02-24-2009, 07:20 PM
It is getting spark. Took plug out hooked to wire cranked over saw good spark. It is getting gas as well. Stuck finger into plug hole and cranked. Compression felt good

smw450r
02-24-2009, 08:22 PM
it sould still start even if the jetting is off, how does the plugs look when you pull them out? does it try to fire up any or does it just turn over

fnmracing
02-24-2009, 08:27 PM
Just turns over. Backfired once. Plug was wet. Put in new one same thing

smw450r
02-24-2009, 08:48 PM
if i was you i would start with checking the valve clearance, make sure everything is in time also, kindof weird since you just rode it, but honestly i don't really know much about this motor, maybe the decompresser is even sticking open, i would start there how did it run when you drove it down the road any stutter and any ticking noises??

fnmracing
02-24-2009, 08:54 PM
Ran great. No noises. Really stumped and pissed off. Will check what you said. Ty for input

smw450r
02-24-2009, 08:58 PM
no proablem man, write back when you tried that, hopefully it fix's it, good luck

quadrider00
02-24-2009, 09:35 PM
check the kill switch position and for excessive resistance with an ohm meter

fnmracing
02-25-2009, 05:04 AM
Hey smw450r I was thinking about the valve suggestion u had. If I am getting compression aren't my valves working. I can feel the pressure at the exhaust as well it cycles like I think it should

smw450r
02-25-2009, 07:33 PM
but if the valves are not closeing all the way on the compression stroke it may be for the cause of it not starting, and it would still feel like it's getting good compression if you have a compression checker now would be the time to try it out, they might be open only a hair, but its enough for it not to start, but like i said weird since you just rode it, take the air box lid off and the air filter and try starting it see if it shoots gas out from the carb when turning it over

fnmracing
02-27-2009, 02:16 PM
30 psi on the compression test. sounds low to me not sure what it should be though. took intake boot off of carb and watched as i cranked it. no fuel shooting out of it.

smw450r
02-27-2009, 07:17 PM
yea that does sound low look on the internet you sould be able to tell what psi that motor is surpost to put out

fnmracing
02-27-2009, 08:27 PM
I was told it should be between 140 and 150. Does anyone have a pic of the cam gears and timing marks

fnmracing
02-27-2009, 08:29 PM
I was told it should be between 140 and 150. Does anyone have pics of cam gears and where timing marks should be.

gsxrkneedragger
02-28-2009, 11:45 PM
i'm looking in my clymer manual and it says 142 psi with decompresor activated. i will look and see if i can figure out a way to show you the timing from my book. it explains it perfectly

gsxrkneedragger
02-28-2009, 11:58 PM
there you go. start with the exhaust cam. on the number 2 count over 15 pins including the one in the #2 spot. #15 should alight with the number 3 hole. on the exhaust one, #1 should be parallel to top edge of cylinder head. the numbers are all dealing with the arrows that they are with

hope this helps you some. let me know if you need anything else about that.

fnmracing
03-01-2009, 07:34 AM
Ty very much. That's exactly what I needed. When you say decompressor, does that mean full throttle while doing compression test.

gsxrkneedragger
03-01-2009, 08:35 AM
here is more less what it says.
1. warm engine to operating temp
2. ground spark plug
3.thread compression guage in. make sure air tight
4. hold or secure throttle fully open
5. turn engine over til highest number on guarge is recorded

hope this helps. like before, if you need anything else, just hollar

fnmracing
03-01-2009, 08:38 AM
Thanks that's what I did

smw450r
03-02-2009, 07:45 PM
just wondering have any luck with the ltz yet?

fnmracing
03-02-2009, 07:49 PM
not yet. Ordered big bore kit, when I ordered timing chain. It was out of time. Tensioner maxed out chain stretched out. Figured since I had it torn down I would go ahead and do the mods I was gonna do later. Thanks for keeping tabs on it though. Parts should be in this week. Had to order new spokes for the boys rmz250 to.

smw450r
03-02-2009, 08:03 PM
that's kool man glad you figured out what was wrong with it, check my 450r i'm building im not done with it yet, getting there though http://viewmorepics.myspace.com/index.cfm?fuseaction=user.viewPicture&friendID=267389009&albumId=1057693

fnmracing
03-02-2009, 08:06 PM
Cool I will check it out. Also ordered +3" swingarm for it to

smw450r
03-02-2009, 08:09 PM
that's good what kind did you go with?