Arctic Cat Forum banner

1 - 20 of 33 Posts

·
Registered
Joined
·
32 Posts
Discussion Starter #1
I've been trying to get my 2004 250 4X4 running for a couple weeks now and I'm out of ideas. Anyone that has something for me to try.. I'll certainly give it a shot!

It became hard to start but after a few minutes of cranking it would eventually fire up and run fine the rest of the day. Once it sat over night it took another 5 minutes or so to fire up again. This went on for a few weeks but now it wont even try to start, not even a sputter. Here is what I've done so far.

I replaced the spark plug and checked to make sure it was getting a spark. I took off the carb and tore it completely apart and cleaned everything. All the parts inside the carb are now spotless and there are no holes in the diaphragm.

I have the airbox open with the filter removed and after a few minutes of cranking little specks of fuel spit out the intake and into the airbox. After cranking for a while I also noticed fuel starts dripping from a nipple and hole on the bottom of the carb. This makes me assume its getting fuel I dunno
 

·
Premium Member
Joined
·
8,170 Posts
well if you confirmed it has fuel and spark thats proper then you must not have compression because thats all that is left thats required
 

·
Premium Member
Joined
·
1,061 Posts
My 300 did the same exact thing it was the intake valve was too tight I would bet that is ur problem. To adjust the intake valve put it on top dead center on the compression stroke then take the valve adjustment cover off and loosten the nut then back the screw off un till their is just a little bit of Play just a tad bit then hold the screw and tighten up the nut. Put the cOver back on I bet u it will start
 
  • Like
Reactions: kingofquartz

·
Registered
Joined
·
32 Posts
Discussion Starter #4
I dont have a way to accurately test compression but I pulled the spark plug and stuck my finger in the hole and there is enough compression to blow my finger out of the hole.

Maybe its getting too much fuel? I've always hated carbs.. they are my worst enemy.
 

·
Registered
Joined
·
32 Posts
Discussion Starter #5
My 300 did the same exact thing it was the intake valve was too tight I would bet that is ur problem. To adjust the intake valve put it on top dead center on the compression stroke then take the valve adjustment cover off and loosten the nut then back the screw off un till their is just a little bit of Play just a tad bit then hold the screw and tighten up the nut. Put the cOver back on I bet u it will start
Thanks so much for a new lead! Once I get done with my work tomorrow I'll give it a shot!
 

·
Premium Member
Joined
·
8,170 Posts
finger test dont mean crap really get a proper test if valves dont fix it
 

·
Premium Member
Joined
·
1,061 Posts
I'm 99.999999999999999999999998 percent sure that's your problem the compression is blowing the fuel back through the carb
 

·
Registered
Joined
·
32 Posts
Discussion Starter #8
I'm 99.999999999999999999999998 percent sure that's your problem the compression is blowing the fuel back through the carb
Any pointers for someone thats never done anything like that before? I'm not even sure where the valve adjustment cover is :Bangin:

There is no way I'm taking it into the dealership again. When I took in my old 250 suzuki they charged me $600 for a new tie rod, wheel bearings and brake pads... insane.
 

·
Premium Member
Joined
·
1,061 Posts
Well when u take the seat off the cover is on the top of the motor it's a circle with a nut on it first take the spark plug off and take a flash light and look into the cylinder now look to the left a bit then turn the motor over with the pulll starter And u I'll see a valve open up when the pison comes back up stop when it's at te tippy top of it's stroke then take that cover off and loosten up the nut then loosen up thescrew unit it has just a tad bit of play when u move it up and down the tighten it back up
and make sure their is still a tad bit of play
 

·
Registered
Joined
·
32 Posts
Discussion Starter #10
Well when u take the seat off the cover is on the top of the motor it's a circle with a nut on it first take the spark plug off and take a flash light and look into the cylinder now look to the left a bit then turn the motor over with the pulll starter And u I'll see a valve open up when the pison comes back up stop when it's at te tippy top of it's stroke then take that cover off and loosten up the nut then loosen up thescrew unit it has just a tad bit of play when u move it up and down the tighten it back up
and make sure their is still a tad bit of play
Thank you so much for taking the time to help me out. I probably wont be able to do this until Monday but when I do I'll let you know if it works!

I just got new oversize tires, a lift kit and a Garmin GPS... its driving me crazy not being able to ride. Not to mention costing me money because I use the ATV for work.
 

·
Premium Member
Joined
·
8,170 Posts
your suppose to use a feeler gauge to measure valve clearance...i really dont suggest winging it out of wack valves kill motors
 

·
Registered
Joined
·
32 Posts
Discussion Starter #12
your suppose to use a feeler gauge to measure valve clearance...i really dont suggest winging it out of wack valves kill motors
Do you happen to know the intake valve clearance on the suzuki 250 engine? I can imagine it would not be a good idea on a really complicated motor.. but the 250 suzi motor is pretty simple. I very seriously doubt the guy who rebuilt my motor used a feeler guage on anything. Not every job requires absolute perfection.

If I check it and can tell its too tight then I dont imagine it will hurt to loosen it up just enough to get the motor running again.
 

·
Premium Member
Joined
·
8,170 Posts
nope havent a clue the spec...sorry to say but one area you dont wanna dick around and pretend specs dont matter its your motor.

But hey what do i know maybe the 250 isnt like any other valve motor and it just goes by feel ;)
 

·
Registered
Joined
·
32 Posts
Discussion Starter #14
nope havent a clue the spec...sorry to say but one area you dont wanna dick around and pretend specs dont matter its your motor.

But hey what do i know maybe the 250 isnt like any other valve motor and it just goes by feel ;)
Honestly, you havent been much help. I'm sure you know a good deal more about engines than I do but you need to realize that not everyone cares if their engine is in spec to a thousand of an inch. Its pretty safe to say that most mechanics arent going to buy a book for every model ATV out there and adjust the valves to the exact factory spec. Meachanics have been servicing valve motors for decades upon decades without giving a hoot about factory valve clearance or reading torque settings from a book.

I'm trying to do this myself for as little money as possible. So far you have told me my finger test is "crap" and told me to buy a tool I might use once in my lifetime. Then you shot down solid advice from someone who fixed the same model ATV with the same problem without having to spend any money. I know the mechanic I can afford would fix it the same way chris has suggested.

Not everyone needs everything exactly perfect to feel good about themselves. I just need a running quad and cant afford to pay someone or buy extra tools to do so. I'm sure you mean well but you come across as a bit arrogant and rude.
 

·
Premium Member
Joined
·
1,954 Posts
Intake:0.03-0.08mm (0.001-0.003in)

exhaust:0.08-0.13mm (0.003-0.005in)

I have yet to find a feeler gauge go smaller then 0.008in so good luck.
 

·
Administrator
Joined
·
38,005 Posts
I'm sorry but savage is right the difference between a valve that is too tight and a valve that is too loose can be as little as 2 thou.There is a reason ALL engine manufacturers provide valve clearance specs.You can burn valves,burn valve seats,bend valves and create many poor running issues such as yours.If your mechanic sets valves by feel ......get a new mechanic IMO..Cat happy
 

·
Registered
Joined
·
8 Posts
A different thought

Just an experience to share about simular problem many years ago. I was 15 and rebuilding my cr125 with new rings, seals, etc. I also took the carb apart and cleaned it. I was having problems with keeping power in the bike on big hills and hard starting.

When I cleaned the carb I made it spotless but forgot (did not know better) to take the oring off and check it for problems. Not only that but I must have gotten a little carb cleaner on it becuasue it was "burned" when I did eventualy look at it. The point is at first I did not replace that oring and on reasembly the bike would not run no mater how much kicking and starter fluid I used. Finaly took the carb apart and replaced the oring and it was like magic. Just a little "burn" or split in the oring and you wont be able to start it.

Just an Idea. Good luck!
 

·
Registered
Joined
·
32 Posts
Discussion Starter #18
Well when u take the seat off the cover is on the top of the motor it's a circle with a nut on it first take the spark plug off and take a flash light and look into the cylinder now look to the left a bit then turn the motor over with the pulll starter And u I'll see a valve open up when the pison comes back up stop when it's at te tippy top of it's stroke then take that cover off and loosten up the nut then loosen up thescrew unit it has just a tad bit of play when u move it up and down the tighten it back up
and make sure their is still a tad bit of play
I would like to give you a good firm virtual hand shake. I couldnt wait until after work because I was too excited to give it a go. I went out this morning and took the carb assembly off and did as you suggested. It fired right up Cat happy It sounded like there was a bit of a tap so I took it back apart and tightened it ever so slightly and its now back to running like a top. Without your advice I know I wouldnt have figured it out myself and ended up paying someone else god knows what to fix it.


Intake:0.03-0.08mm (0.001-0.003in)

exhaust:0.08-0.13mm (0.003-0.005in)

I have yet to find a feeler gauge go smaller then 0.008in so good luck.
Wow.. its actually that tight of a clearance. Geez... thank you for taking the time to find the specs for me but I dont know how in the world I'd measure that kind of tolerance. My set of feeler guages only goes down to .010
 

·
Premium Member
Joined
·
1,061 Posts
Well If your motor doesn't tap or start hard then I would guess that its ok. As Savage said sometimes is better to do it right by the book on my 450 KXF, when I do the valve's I make sure everything is spot on but on my 300 I just do it by feel. I guess I just have a good since of feel. But I defiantly see where Savage is coming from but sometimes you have to ask yourself "Is it worth it"?
 

·
Registered
Joined
·
6,867 Posts
Here is a feeler set that goes from 0.0015 up to 0.035. Cheap too $6.29. Any local auto parts store should be able to get a set like this for near similar cost.

LISLE TOOLS 68100 DELUXE FEELER GAUGE | eBay

The thickness of a human hair is typically ranges from 0.003 to 0.005" Its been stated before. A difference of approximately 0.002 too tight may make the difference between burning a valve and undergoing very expensive head work. (Valve grind and valve replacement) Sitting valves by feel is taking a huge risk in my opinion. Couple thousands of an inch too loose and you'll develop poor power. It's your engine and your money. Do what you wish. Less than 10 dollars to prevent maybe several hundred in damage is a no brainer in my opinion
 
1 - 20 of 33 Posts
Top