Starting problem

[RJ450]

Hi all:
I've been having starting problems with my quad and I wonder if any of you guys can help a brother out.

I have a 2004 YFZ450 a bid modified.
(curtis sparks exhaust with Jet kit stage 1, I didn't remove airbox, Hot cams, Intake is ported, High output stator with rectifier, Dynatek FS CDI rev box, High flow impellar, Oil super cooler, Uni airfilter, R&D power pump quickshot, Hot rod connecting rod kit, replaced sprockets front one is a tooth or two more)

So now I bought a new starter thinking that the starter was the problem but appearantly not oh and I also bought a new relay switch. I cleaned and brushed the batt wires making sure it has good connection but still doesn't start the engine. I am starting it by pushing it in nuetral and start it in second gear. Engine is very powerfull and runs good, it idles with no problem accellerating in high rpm it kinda bock and decellerates perfect not backfiring.

When I start the engine I think it moves the piston one time then it sounds like the battery has no power. Batt is brand new fully charged 12.6 or higher.

Thank you for your time and hope we can fix this thing together, happy holidays ;-)

[<DRS>GPF]

if youre saying that it wont roll over, like a dead battery, it could be the negative connection, rather than the positive..

jump a cable from your battery negative to a mounting screw for the starter

[RJ450]

Hey there friend,
I connected a cable to ground but still wont start. I pulled out the spark plug and start hit, and it sounded like battery is low. Battery is actually brand new and fully charged.
Like I sadi the engine runs fine but do you think maybe it has something to do with the engine itself?

[glwitmer]

it could have something to do with your rev box. I am always having problems with my 400ex cuz of the rev box

[the Z Man]

try jumping across the celanoid (sp) see if that is any better, maybe your start button has an issue..
Follow your positive cable to where it connects, jump across the 2 red cables..

[RJ450]

I actually bought a new rev box few months ago still does the same.

Also the celenoid switch I already checked that and changed it and tried it with two other ones and still does the same.

Now I'm thinking of opening the cam cover and check the dots on the cam sprocket which should line up with the top of the head "the TDC", de-compression and valves.

[the Z Man]

If that doesn't work... put on a kick start!!!!

[pro-rider46]

my friends yfz has EXACTLY the same problem as yours, and it just seems like it doesnt want to start, sometimes it starts right up. other times, it does exactly as you described it, if you ever figure it out, pm me with what you got, i would really appreciate it.

[RJ450]

Yeah I was thinking about getting a kick start.

Actually that's how the problem started, sometimes it starts weak and other times it didn't. Well neway, I'll keep you posted if I figure it out tomorrow.

Ps, hey when it all started I bought new battery like 4 times, I even bought a battery charger then I bought celenoid switch, change starters brush, new starter, high output stator and rec/reg, starting switch... man this is driving me crazy, but hey I still keep my hopes up.

[RJ450]

Hey all,

Well I finally got my quad to start again with the switch.

The problem was the de-compression release vavle, it wasn't opening. This is bcz there was to much clearance between the valve and the cam, between them you'll find the shim which needed to be replaced. No my quad finally starts again. Everything is set again and ready to hit the road.

Thanks for all your help, RJ