about ready to give up. starting problems

[Pimped_wart_no2]

i am having some serious problems with my wife's 400 starting. has always had a little problem but jetted it in and got better and then comes back and don't know why. now... for the explaination. has plenty of spark. carb was pretty dirty so i think the boot may have came off or filter was over dirty from some neglect. but took carb off cleaned everything and sprayed out all ports. put new plug in and still has plenty of spark. battery is shot from this problem but hooked up to my yfz while it was running just to get it to turn over steady and it will not start.

there is fuel coming out of the carb when i hit the throttle so the accel pump is working and i pulled plug and it was not flooded.

tried push starting and that would usually work if the electric would fail but even push starting it would not fire. took starter off and cleaned it inside to get better connection before all this. checked valves and they are in spec. .004 on intake and .005 on exhaust. did not adjust them they were set at this since 2009 when i got the quad.

basically all the elements are there for the quad to start and i don't know why it won't. i am pretty mecanically inclined and do all my own builds and fight threw everything myself to get things running perfect but i am honestly sick of this 400 problems. maybe because i don't ride the quad personally. lol.

if anyone has any input on what they think let me know. thanks

[honda400ex2003]

im leaning toward an electrical problem but it is hard to tell as it could be jetting related and such. it may not be getting enough gas to start it esp if the plugs not getting fouled up at all after turning it over for some time.

first thing i would do is get a new battery and install it.

the cdi could be messed up causing problems. does it have an aftermarket one on it? aftermarket ones are known for having starting issues if the battery is not in good working order, even while trying to jump start them.

what is the jetting at and what are the mods done to it engine wise?

steve

[Pimped_wart_no2]

i am running a 145 main and a 50 piolet. needle is on the middle clip or 3rd from top or bottom and is a #44 needle. stock carb.

as far as i know the cdi is stock. it is black with no aftermarket stickers or anything on it but i have not gotten one since i bought the quad. i have been looking on ebay and stuff trying to find a cheaper one to swap it out with to see if it helps but have not found anything in my budget yet. motor i do not know if it is bored or stock as i have not had it apart. it doesn't run any stronger than other 400s that i have ridden so i don't think it's anything special. just a fun fact... the guy i bought it from said he had a stroker crank with a spacer plate under the cylinder to give it the extra room to travel. i laughed and said hey for 1400 i don't care what you have to say about it cuz it had lsr components and axis shocks. told him i don't even care if it runs. lol but a spacer plate under a 4 stroke... must have gotten the extended cam chain and different sprokets to get the timing right. lol.

but that also i checked the cam chain tensioner and it was not backed off and there is no rattleing when turning over to suggest cam chain slop to i don't thing it could've jumped timing at all. kinda flusterd. ready to buy an fcr and put it on there and see how it starts. thanks

also bought a new battery and it is on it's way. went with a better battery... aka not walmart. new gel battery or something.

[honda400ex2003]

i would at least go back to the 148 main jet (stock), a stock 38 pilot jet, and go 2.25 turns out on the f/a. needle on the 3rd notch is correct for stock apps.

that would be the first place to start with getting it closer.

the odds of having any motor work seem to be pretty slim so i am going to assume stock stuff on jetting also. a 50 pilot is too much for a stock carb and a 145 is too little for a stock carb. so it is getting too much gas while trying to start up and not enough to keep it running when hitting the gas.

get the battery in there and the correct jetting for a stock machine and see how it goes.

just my thoughts on it, i would def try to pull the head cover off and look at the cam, also try to look at the piston or do a compression test to give an idea of if it could be different or not.

steve

[eprovenzano]

I agree with steve, the jetting is off. He is one the money with the specs of 148 main jet, a 38 pilot jet, 2.25 turns out on the f/a. with the needle on the 3rd notch.

If you have access to a compression tester, that would be good also for reference.

[Pimped_wart_no2]

I do have a tester but what is it going to read with the auto decompression active?

[eprovenzano]

I'm just thinking outloud, that it would be good to have a baseline for the current compression number.

[honda400ex2003]

it should be around 125 for a stock engine and more for aftermarket. it would depend on the comp ratio and such of the piston.

steve

[brokenmike]

Does it fire with starting fluid?

[Pimped_wart_no2]

have not made it to the store to buy any starting fluit. it would not fire on carb clean but i know carb clean is more liquid than a starting fluid. i will be working on it tomorrow. new battery came in today so i'll try rejetting see what happens before i run to the store to get some starting fluid

[DragonGunner]

You say it gets spark, an gas in carb but its not flooded.....TRY AN FLOOD IT, pump like crazy an then check your plug, if your plug is still dry your still not getting gas to it, carb is still in need of cleaning.

[tri5ron]

cracked/torn carb boot ?
bad needle seat?
stuck float?