I have an o5 YFZ 450 SE with no mods yet. I am having trouble starting it. I know about the whole charging problems with these things and I just recently bought a resistor kit but havent put it on yet. Acouple questions though, Should I get a larger battery because of the Compressi0on of these things???? would it be my spark plug that just isint sparking??? the battery isnt totally dead because it is turning the engine but it just wont start. any Ideas??? I know the 04's and 05's are known for this problem, what are some ideas to get rid of it totally??? The cold effect these things like crazy and it kinda pissses me off.

 

Put your battery on charge for a while and try again, the 04 yfz's sound like there turning over fast enought but arnt. That what happens to mine all the time. And when its colder than minus 20 or so, i dont even try to start mine.

 

how long has it been since you last rode it? If it has been more than a couple of months then the fuel could be bad. I have also heard of a lot of the yfz's having problems with not cranking fast enough when the batteries get a little low. Also, cold weather requires richer jetting...the factory needles are not adjustable and the air adj. screws are capped so low speed adjustments require some modification.

 

Its been about two months or so since I road it last. It has been in a garage the whole winter but it wasnt a heated garage.

 

I am having trouble with mine as well. When I got it it had a bad battery. I ordered one online and it sat in my basement for two months, I put it in on Thursday and had to charge to get it to crank over. left it in the back of my truck over night, and friday evening I go to start it to put it in the garage and it want turn over fast enough. WTF! it is brand new battery. I hav it on the charger right now and will try again tonight. Maybe I need to get a tender for the colder months, I just don't want the headache of buying a bad battery.

 

My 04 still has the same battery that it came with and no electrical mods... Guess I'm just one of the lucky ones... I've let it sit for 2 months and she started right up with a quick spritz of carb cleaner... [img]i/expressions/face-icon-small-smile.gif[/img]

 

Sounds good Hebs, but can you give us some help if you are going to rub our noses in it? [img]i/expressions/face-icon-small-happy.gif[/img]

 

First, the '05 DOES have an adjustable needle and the fuel screw IS NOT blocked off. That nonsense didn't begin until the '06 model year, God Bless the United States Government. Second, the stock battery is woefully underpowered. I am still on the stocker but plan on upgrading soon. There are a few batts that will fit with a small amount of modification to the battery box. Do a search but I have heard that one of the CBR600 batteries fits well, and the Warrior batt will also work. Going with more amp/hours will aid in starting, even more so in the cold or heat. If you live where it gets cold, you probably could stand to richen up the needle and maybe go one up or so on the main as well. Buy an aftermarket fuel screw and do a search on how to tune with that as it really helps with starting and low end overall. You can do a quick check on the plug by pulling it and turning over the motor while grounding it against the frame. That will at least let you know if you have spark. Other than that it would be a good idea to put fresh fuel in, a new plug regardless of how it looks, charge the batt and have at it.

 

ugly88... have you tried running it with your headlights on the whole time? Many people w/ 04's state that was the only way theirs wouldn't wear the battery down... (sounds odd, I know... but might be worth a try...)

Otis... Pop the spark plug off... Is it black? Stick it in the plug wire and hold it up to something metal on the quad and try to turn it over... Is it sparking good? Is the airbox lid on or off? If it's on, pop it off and try to start it... Still no luck? Spray a lil carb cleaner on the air intake... (do it from a distance, you just want it to suck in thru the filter, not soak it...)

 

Actually I just bought the machine in December and the guy told me it had a bad battery, when I test rode it we jumped it off another machine.

So once I had it in my possetion, I ordered other battery on line by the end of December, I had it sitting in my basement until last week when I had time to take it to my buddies garage to change the oil and filter and go over the machine and make adjustments. When I put it in after being charged it still only cranked it slow?

So with the weather here in Wisconsin the way it has been, I have not had much time to ride it with the lights on but I have heard that before.

I have heard of the CBR 600 battery being better, so if I have to dump money on another battery I will probably just do that it it will help in the cold?

Thanks for the help and suggestions, I will check the plug and maybe take the machine in to get eh valves adjusted.