quad started bogging all of a sudden.

[Honda4life05]

today i went riding with a couple of buds and about time to leave, my quad would backfire and just bog anything past 1/8th throttle. it just happened all of a sudden so i know it isn't jetting. could the jets be clogged? i already checked an the gas flows out of the tank just fine but i haven't messed with the carb. also could it be electrical? i'm asking becasue i want to hear the commom problems that sound like this before i check it out deeper. thanks

[Baileygunns]

Do you have an aftermarket fuel screw? Check and see if it's still there. Then check your stator.

[DnB_racing]

if your wiring has been altered at all, check connections. also give your wire harness a quick look to check for areas that could be getting wet or going to ground.




How dirty is your air filter? clean air filter, and clean carb.





make sure no metal in oil. it will stick to mag and cause bog

[nskukalek79]

I've had this problem before....my carb fell out of the air box side boot but still looked like it was in place...it ran fine at low rpm but once i started revving it a little it would just bog...if you haven't checked the carb yet this might be your problem. Just loosen the clamp and put her back together....make sure there is no grease on the boot of carb

I hope it's nothing major

[Honda4life05]

sorry i've been out of town, but my fuel scre is stock, and i checked the boots for leaks and it was fine. what's wierd is it runs perfect at idle an a little past ilde. i check the needle and it looked good. should i check the main jet to see if it's plugged? any other jets to check? where are they? and my wire harness is stock so unless a connection came unplugged idk what it would be. thanks for any help, i need it for a race this weekend..

[DnB_racing]

give your carb a good cleaning and blow out with low air pressure

[mx Eli]

yea just go through the whole carb just to make sure

[RobRacing]

Did you leave your airbox lid on after you washed it? I did that once and had the same problem you are having, took it off and it ran perfect.

[Honda4life05]

okay guys here's a little update! when it's runnning past 1/3rd throttle it is blowing black smoke, so i know it's running rich. and i took the plug out an seen unburned fuel on it. so somehow it is runnning rich. think my plug is bad? i'm in the middle of cleaning the carb and it didn't look too bad. any other things to check for making it rich??

[DnB_racing]

your carb doesnt have to look dirty or sludged up to be plugged up a little, Just do a GOOD cleaning, take all jets out, open a/c pump clean all the ports with some spray then blow out ALL ports and add a new plug and Id be surprised if it didnt fix your problem.

if any of the o-rings or rubbers are dry and craked replace them all

[Honda4life05]

I cleanned the carb REALLY good. got a new plug and NOTHING. now it's really starting to piss me off. i think it's not getting spark at high rpm's but idk how to test any of that.

[Baileygunns]

Any chance you checked your stator yet? Pop the engine cover off and look at the pulse generator and see if there's any metal shavings on it...

[Honda4life05]

the cover by the oil sight glass? do i have to put a new gasket if i take it off? also any other things?

[stoopidbot]

Are you running gas with ethanol in it? I have seen gas with 10% ethanol do that to quads...

[Baileygunns]

Yes, left side engine cover... Do you have a service manual and a mulit tester? The manual will tell you how to test the stator... A tell tale sign is the metal shavings on the pick up. It can do some funny stuff, from no spark to weak spark....

Let me know if you need a manual...

[Honda4life05]

yea but i've ran the same stuff since the motor was rebuilt. i know that's not the prob.

[Baileygunns]

04/05 Service manual (http://www.filefront.com/13907168/05trx450rSM.zip)

[300racer]

mine did something like this and it was a couple teeth off on timming.

[Honda4life05]

how do i check the timing??? i was thinkin that had something to do with it. also, i don't wanna pop the engine cover off because then i have to order a new gasket.

[DnB_racing]

you dont have to worry about gaskets to check timing


READ THE MANUAL that bailey linked for you I belive 4/24 is timing page I could be wrong on the page but read the good book

[Honda4life05]

no i meant the gasket for checking the stator. but for some reason it won't let me download the manual??? it just goes back to the same page every time. any others?? after searching it sounds like my timing is prob it.

[Baileygunns]

Try it again... That manual has been downloaded almost 900 times...

[DnB_racing]

Originally posted by Baileygunns
Try it again... That manual has been downloaded almost 900 times...

901 I just downloaded it to check if still available!

[DnB_racing]

Originally posted by Honda4life05
no i meant the gasket for checking the stator. but for some reason it won't let me download the manual??? it just goes back to the same page every time. any others?? after searching it sounds like my timing is prob it. first check you oil filter and drain oil looking for fine metal specs

[Honda4life05]

okay got it. can you tell me where it shows how to check timing?? i checked all of them.

[DnB_racing]

there isnt a brake down on timing (with timing light) but check cam shaft assymbly that will show timing marks check 4-8 and 9-26 and start there, it will get you started in the right direction for valve clearance and cam timing

[Honda4life05]

okay thanks. so pretty much to check timing, the marks should be alligned on the cam sprocket, and at the same time the marks on the crankshaft line up on the compression stroke? also how do you know it's onm the compression stroke?

[Baileygunns]

^^cam lobes will be pointed to the back of the quad... But again... Have you checked your stator yet? Unless you spun your cam flange which I doubt... or your cam chain is so stretched it jumped timing, which I doubt... or you just put a cam in it and put it back togeather wrong, which you didn't say you did... I would check the pick up for metal shavings...

DnB... What are you talking about with a timing light? This ain't no small block Chevy here...

[Honda4life05]

update! i just checked my timing and it looks spot on. but i still have to check my valves. how do i check the stator without taking the engine cover off and have to get a new gasket???

[DnB_racing]

Originally posted by Baileygunns
^^cam lobes will be pointed to the back of the quad... But again... Have you checked your stator yet? Unless you spun your cam flange which I doubt... or your cam chain is so stretched it jumped timing, which I doubt... or you just put a cam in it and put it back togeather wrong, which you didn't say you did... I would check the pick up for metal shavings...

DnB... What are you talking about with a timing light? This ain't no small block Chevy here...
lol..he was asking about timing and I just wanted to basically say that you have to line up the lines and that's what the SM shows, I guess i put that a little messed up to understand!
but I have put a light to mine and it does work!

[DnB_racing]

Originally posted by Honda4life05
update! i just checked my timing and it looks spot on. but i still have to check my valves. how do i check the stator without taking the engine cover off and have to get a new gasket??? to check the electrical system you need a good multi meter with peak hold (fluke) or any good meter, and it might be out of your scope, but page 16-4 is the sequence to testing electrical system,

but you should be looking for metal first as it will adhere to your flywheel magnet and will cause issues! does your oil have a metallic shine to it? if so pull the cover and check for shavings

[Baileygunns]

If you're that tight on money or the dealer is that far away you can get some high temp gasket maker/RTV at the local auto parts store... It's usualy red or black. It will work and I have used it on clutch covers and stator covers before... Just go light on it becuase the extra squishes out when you tighten everything down.


DnB... What are you shining the light on to check timing? I don't doubt it will strobe but unless you're jamming out to some techno what would you do with it?

It's been so long since I've touched a timing light... lol.. Kinda miss the ease of tuning with them.

[DnB_racing]

if your careful you might not ruin the old gasket


the lite will show the idle "F" mark on flywheel its not much good for anything but to check that its sending spark every cycle



edited out mistake

[Honda4life05]

another update! i put my cdi box on a friends quad, and it ran fine so that takes another thing out. and also i put my light on and started my quad and reved it up till it bogged out, and the light never dimmed or anything. so i don't think it's the stator either. anything else to try??

[DnB_racing]

Originally posted by Honda4life05
another update! i put my cdi box on a friends quad, and it ran fine so that takes another thing out. and also i put my light on and started my quad and reved it up till it bogged out, and the light never dimmed or anything. so i don't think it's the stator either. anything else to try??

so there are no shavings in oil? cdi is good? timing is good?carb is good?plug is good?any broken valve springs?exhaust plugged?air filter is clean?
then it might be time to tear it down

[Honda4life05]

i checked the valves while i checked the timing. on the intake valves the exact size feeler that is needed was a little hard to get in, but it went in. so it can't be off by too much. (i think it can be off by +- 000.1) and i went by the manual. what do you mean by time for teardown? this motor is less than 15 hours old. and it runs perfect at idle and a little past, has no shavings in the oil. i figure it's electrical but there are soo many little things it could be. anything else i missed??

[DnB_racing]

I didnt know it only has 15 hours!! the reason I said tear down is I was thinking a bad bearing or along those lines, but if its fresh??

I really dont think its electrical,unless its going to ground at stator from shavings but???? Im still thinking it might be carb! i know you took apart and cleaned, any chance you missed something? as far as electrical you can test everything except CDI but you need a good meter

[Baileygunns]

The shavings interupt the signal to tell the coil to send a spark...


But hey... Clean the carb again. That's easier than taking the engine cover off.... Right?

[DnB_racing]

ya I was thinking that it was from shavings, until he said no sign of metal in oil. usually the oil has shinny metallic look. if there is enough metal for interrupt the signal. the shavings will stick to the flywheel causing havoc, but the small particles can still usually be seen in oil. if no metal in oil I think it has to be carb,

but Baileys right pulling the cover only takes like 3 minutes. for the piece of mind its worth doing! if you dont have a way to get a gasket the WORST is you will leak a little until you can get one

[fastredrider44]

Originally posted by RobRacing
Did you leave your airbox lid on after you washed it? I did that once and had the same problem you are having, took it off and it ran perfect.

I did this once. Glad I'm not the only one.

[fastredrider44]

If you are careful, the gasket will stay on the cover and not tear.

Sounds like more of a carb/air problem than electrical to me. Ohm out the coil going to the spark plug boot if you think it's not sparking at high RPMs.

[DnB_racing]

as far as ohms on the coil unless he has ohm-ed his out before or has another one the value wont show much, if hes getting spark at low rpm then the coil has continuity, testing only shows good or bad it wont show if its failing at high rpms

[Baileygunns]

Very rarely do these coils go bad... Honda has been using the same coil on multiple machines for many years... It's a good design and generally doesn't fail... There are other things in the circuit that will fail first...

Grab your buddies rectifier/regulator and swap that out just to eliminate it from things that could be wrong...

[fomospede]

this may seem stupid but have you checked to see if exhaust is clear ?? a buddy of mine found beanie babies that his lil daughter had crammed in his!

[Honda4life05]

that's funny about the beanie babies!! lol but no i keep a plug in my pipe, and i made sure it was out. but i finnaly said **** it and took it to the shop. I know i may get raped in the butt with labor but he said he thinks it's something in the carb. (my buddy is a honda tech) so i'll let you guys know when it's done what it is. i have a race sat. so hopefully it's done! thanks for help everyone.

[fastredrider44]

Originally posted by Baileygunns
Very rarely do these coils go bad...

Stranger things have happened.:blah: As far as Ohming them out, the manual should have the values to look for. At this point, I think I have seen every single part fail or get replaced on a 450R at some point in time.

[Honda4life05]

hey guys another update! the guy did a leakdown test and it had low compression, so he thinks it's the rings. even though they have about 20 hours on them. sadly enough i did get a little sand in the motor from running all day in a sandy place. i cleaned my foam filter before i rode but i rode all day so when it's fixed i'm gonna get 2 filters. so my question is, how does it run like poop from low compression?? i thought it would just lose power.. thanks!