r wont start please help!!!

[mhewitt]

06 450er, guy i bought it from says the starter was burnt up i replaced it,still nothing. i replaced solenoid, nothing. the wires to the start button were broken, replaced those now it tries to start (finally). but still will not start, if i push start it runs but wont idle. i took the carb apart and cleaned it put it back together adjusted it according to honda service manual 2 and 3/8ths turns out still wont start or idle. any ideas??? its all stock except for uni air filter air box lid on

[MR4Engine202]

time for a valve adj.

[bk111]

No idle=tight valves

[mhewitt]

ok after pushing it and letting it warm up good i readjusted the idle with the dial that comes off of the carb above the head and now it will idle but still wont start, i rode it for about 15 minutes today and noticed the header was glowing red all the way around the bend, i think that means its running lean? and when i tried to ride it with the airbox lid off it would just bog at anything more than 1/4 throttle. which suggests lean too right? anyone know how much i should turn the air/fuel mixture screw out to correct this? i dont have the tool so have to pull the carb off to adjust so i would like to not be guessing in the dark

[mhewitt]

anyone give me an idea of where to start?

[YOURADHERE]

Originally posted by mhewitt
anyone give me an idea of where to start?


Looks like 2 people already have...


Originally posted by MR4Engine202
time for a valve adj.



Originally posted by bk111
No idle=tight valves

[mhewitt]

i meant where to start on the air fuel screw as u can read those were the solutions suggested were because of my bike not idling correctly. now it does so thanks for your 2 cents

[DnB_racing]

you have to get the tool needed, its only a few bucks and follow manual instructions as far as adjusting until max rpm's if out over 3 turns you have to go larger pilot,

here is some info on jetting


http://quadhub.com/wiki/index.php?title=Jetting_theory

[YOURADHERE]

Originally posted by mhewitt
i meant where to start on the air fuel screw as u can read those were the solutions suggested were because of my bike not idling correctly. now it does so thanks for your 2 cents


Every symptom you mentioned in this thread is a direct symptom related to valves being out of spec. Sure turning up you're idle adjustment helps it idle but the fact still remains that there's a 99% chance the valves need adjustment. It's necessary maintance on pretty much any atv engine, just so happens 450s need it more often.

The glowing header is somewhat common. Some will say its a sign of being too lean, other's will say it's just one of those things that happens.

However, I still stand by what was previously mentioned. Your valves are out of spec. Get a manual, check them and adjust as necessary. It's a fairly simple job.

[mhewitt]

my header was glowing in broad daylight 12" from the head , i have searched posts about it and no one elses was as bad as mine, didnt mean to sound like a jerk but i have experience n building engines just not carbuerated ones. this doesnt seem like a valve adjustment issue to me but i will check to be sure they r in spec. the manual mentions a carb n throttle switch that might b keeping it from starting but doesnt say how to check them anyone know? im gonna turn the screw out a half turn to see if that cuts down on the glowing of the header

[mhewitt]

does the accelerator pump only work when trying to start or does it work all the time ?

[YOURADHERE]

Let me be a bit more clear, the glowing header and the no starting/tough to start/no idle are likely not linked at all.


The glowing header is likely due to a slightly lean condition. Is it popping/backfiring on the decel? Try going up a size on your main jet and see what that gets you. To be honest it may still glow. Ive seen several atvs that run great but still have headers glowing.

When valves are out of spec it'll do EVERYTHING you mentioned, except the glowing header, which as mentioned before can be common on perfectly running engines. 1) It won't start with the electric start. 2) It'll start by pull starting/push starting. 3) It won't idle well/at all.

[DnB_racing]

Originally posted by mhewitt
does the accelerator pump only work when trying to start or does it work all the time ? your accelerator pump works every time you jab your throttle from a idle position

If you haven't checked valves yet definitely check, but alot of people say they need constant adjusting they dont!!there are other issues, if valves are out its because the valves are either cupping or head is in need of work, I rebuild my top end every season and the valve clearance has NEVER changed from beginning to end of season so if valves are out of spec its more then adding different shims something caused it to tighten! valves dont just grow!!!!

[mhewitt]

due to work and weather i have yet to find the time to work on my quad thanks everyone for your suggestions i will let u know how it goes with the valve adjustment and we will go from there

[mhewitt]

havent noticed popping on decel but havent ridden it very much yet, i have noticed that once the bike is warmed up if i cut it off then try to start it with the electric start it will pop and backfire when trying to start. but only if the exhaust is already good n warm

[kenny450er]

went threw the same problem adjust your valves i bet thier out of spec also while you are in thier adjust your decomp useing a compresion tester and set your decomp compresion 50 to 55 psi.

[mhewitt]

anyone tell me how to adjust the decomp? service manual doesnt really say much about it from what ive seen

[YOURADHERE]

Ive never heard of anyone adjusting the decomp mechanism. I'd leave it as it is.

[Latemodel32]

Originally posted by mhewitt
havent noticed popping on decel but havent ridden it very much yet, i have noticed that once the bike is warmed up if i cut it off then try to start it with the electric start it will pop and backfire when trying to start. but only if the exhaust is already good n warm

poping on decel is a lean condition

Rattling noise on decel is bad muffler bearings:D

[DnB_racing]

Originally posted by YOURADHERE
Ive never heard of anyone adjusting the decomp mechanism. I'd leave it as it is. you adjust the valve clearance to 55-60 psi not the mechanism! but instead of adjusting to spec you adjust to compression its a better way of adjusting exhaust clearance..... Even at recommended valve spec the compression could be out of what's recommended

[MR4Engine202]

"valves dont just grow!!!!"

actually they do stretch a bit over the life time especially in high rpm circumstances being and over service time....but all most all of any valve adj is due to cupping and or poor valve seating surface

[mhewitt]

when i set the decomp at 52 psi the starter would barely turn the engine over and after about 3 tries the battery was too weak to turn it over, brand new battery, i turned it back down to 45psi it turned easier after charging the battery but still wouldnt start i will try again tomorrow

[kenny450er]

I know its be asked but did you check your valve lash and what were they at and did you check your timming marks also not to worry you but the 06 come with titainum valve and they had a coating on them when the coetting wore off the valve seats would beat the **** out of the valves also when you tore the carb apart and cleaned it with carb cleaner did you blow it out threw all the ports and jets with a blow gun and check the accelerator pump diaphram for small hole or tear and the spring and make sure it adjusted properly and just wondering you did put a new spark plug in right ngk ifr8h11.

[mhewitt]

been real busy and havent had time to work on bike much, gotta get a feeler guage set from shop to check valvelash. pulled pug wire off of head n put a plug in the wire n held it up to the motor and when cranking over i didnt see it spark at all, weird because if push started it runs. anyone know what would keep it from getting spark on start up? off today so maybe i will have time to check the valves

[mhewitt]

kenny450r i will also run throuh your checklist whn doin the valves, thanks everyone for your help so far im ready to ride!

[mhewitt]

pushed it again to see if the changes i made to the air/fuel screw helped, header never started glowing but it would pop through the exhaust everytime i would shift under power is that just because i have the baffle installed? also when riding slow and just pinning the throttle theres a moment of hesitation before it takes off, sounds like it bogs then goes

[DnB_racing]

as far as your bog when pinning the throttle ... that happens on the +06 unless your put in a 50 leak jet or do the accelerator pump mods that can include tying the linkage and sometimes the diaphragm stud modification .... goggle acc pump mods and you will get a better description of what Im talking about.

with mine all I had to do is the leak jet, and changed the way I clutched and throttled it!!

[mhewitt]

finally found time, valves are still in spec according to honda service manual. both safety switches are in proper working order (throttle and carb). i am now getting spark at the wire although it seems to look kinda week imo, barely visible at night. i have to order a new plug because this crap hole town i live in dosnt have a decent parts store that can get it. still starts and runs perfect with a 2nd gear pushstart but will not start electrically. really dont wanna give up and take it to the not so local honda shop an hour away just to pay 75 bucks an hour for them to fix it. is there anything that provides spark only during low speed engine operation? gotta be something simple. has fuel, compression, and now spark. what controls the strength of the spark? i was testing with a screwdriver in the plug wire to rule out a bad plug until i get a new one but it just visually looked weak to me but seems like enough to make the engine sputter or something it just turns over

[mhewitt]

i was thinking, manual says compression should be between 50-55psi with mine that high the battery goes dead after just a few turns n struggles to turn the engine over. its a brand new battery but im thinkin that could still be bad and its not turning motor over well enough with the correct compression setting for the engine to start. gonna set comp back up to 52psi then put battery charger on battery so it will stay strong and try cranking it that way. running outta ideas on this thing

[DnB_racing]

If battery is dying that soon you might have a wire in your start button going to ground? maybe

[mhewitt]

battery is charged up good now, new plug gapped correctly, compression set at 155psi, still wont start. no spark is visible through the plug

[mhewitt]

called the local honda shop and they said they have never ran accross this issue so they couldnt help

[DnB_racing]

im sure they wont help unless you pay them!!if they wont give free advice then you should look for another shop!

I am still thinking that you have something grounding out check all wires for burns, cracks, water..... will it run if bump start?

[mhewitt]

yeah runs perfect if bump started, but there is no spark through the plug using electric starter. when the motor turns over, what exactly creates the voltage for spark?

[DnB_racing]

the spark comes from the alt to the coil timed by the pulse generator. its the same place as when your running as when you use the starter to turn motor over, if its not starting with button but is starting with a bump! then for some reason its just turning over to slow. why?or its your valves, but you said your valves are good so it might be either.... starter, battery, or starter clutch,

when my starter clutch went it did the same thing everything seamed fine, but it was just slipping just a little bit(not even enough to hear the difference) when I changed it I haven't had a problem since!!

I couldn't even hear it slipping or any sign that it wasn't turning over at full speed! but it was slipping and caused it not to start!

[mhewitt]

yeah mine sounds like its turning over fast enough, and the starter and battery i replaced with new ones. but if the starter clutch is seperate from the starter then maybe that is my problem. like u said i cant tell that its slipping but it could be. when i put the battery jump starter on it turns the motor real fast but it sill doesnt start so i dont know

[DnB_racing]

if you sure your valves are not the problem and your carb is clean then that's about the only thing left.

before you try changing the starter clutch you might want to make sure its not a fuel issue by spraying just a little starting fluid into air cleaner!

but your problem sounds just like when my starter clutch went bad... it isn't that hard to change out and to do it right it will cost around 200 for all the parts! you can do it cheaper but that might come back to haunt you