atv help? 1999 suzuki 250 atv.

[coolguy147]

welllll, i've been driving my head crazy and doing anything possible on this thing.

check compression....littler over 130-135 (cold)
has 570 miles on it
cleaned carb twice. (every nook and cranny. took over jet out. even main. couldn't get the seat out though? maybe float height is too low allowing not enough fuel to be brought in?)
i messed the pilot adjustment screw but i set it to 2 3/4 out. it's been all the way to 3 1/2 out and it still would act lean.
adjusted intake and exhaust valves twice. the first helped a little.
took carb to engine boot off to clean gasket and applied some anarobic sealant. no help
sprayed brake cleaner alllll around boot to look for air leak but didn't help

my atv is running lean! but i don't know why!?!?1 the atv has noooooo mods.
i get a backfire though the intake and if i throttle up then back off it will backfire through the exhaust.
i ran the old gas out and ran new gas in(cleaned carb again after old gas was gone)

jets have been left alone. when it was running good it was great then it would stall after a while. barely though. then later it started to get a slight backfire through carb.

also, it has a weird problem of like dying for a second then coming back like a intake backfire but not pronounced. after a while i stopped using it as much and it later would only run with the choke until i cleaned the carb

basically my problem is i don't know why but it keeps running lean?
tomorrow i'm going to open the intake valves just a hair incase i got them too tight.

 

[coolguy147]

Re: atv help? 1999 suzuki 250 atv.

i'm going to adjust the intake valve out a hair now that it has sat overnight (cold)

also, i'm going to move the fuel screw out a 1/4 turn. making it 3 turns out.

going to go from there and see. lol.....

 

[JRJ]

Re: atv help? 1999 suzuki 250 atv.

I would make sure the gas tank is clean and check the air filter and intake for debris/nesting material. I bought a new 1988 Suzuki 250 4x4, sold it in 2000 with 6,000 miles or so on it, and the guy I sold it to is riding it today. With so little miles on yours in all these years, it has to be something simple. Good luck.

 

[mla2ofus]

Re: atv help? 1999 suzuki 250 atv.

I have a '96 Suzi 250 4x4. If your's is like mine be sure the fuel pump located below the gas tank is working OK. Mine got gummed up from sitting too long. Cleaned it up and it works great now.
Mike

 

[Fireman431]

Re: atv help? 1999 suzuki 250 atv.

Get with a Suzuki tech and get the settings for the jets on the carbs. Most carbs I have ever worked on were 1-1 1/2 turns backed out, not up to 3. Get the correct info before you keep driving yourself crazy.

 

[coolguy147]

Re: atv help? 1999 suzuki 250 atv.

ok guys. i adjusted the intake valve a hair out. that helped quite a bit with the backfiring but it still runs with 3 turns out

i keep thinking the jetting is wrong but it ran fine before it started to gum up?

i have a service manual but the setting it gives me is 2 7/8 out. California is pre-set.

i know how to adjust valves but this motor is so cramp to get to them i can never tell whether is perfect or not. the feeler gauge keeps hitting the side wall and binding.....i might just take it in for a valve adjustment job. tell them to adjust on the big side. $100...

last time i tried to call my dealer, they told me the mechanics were busy and that they will call me back.

they never called me back.

 

[coolguy147]

Re: atv help? 1999 suzuki 250 atv.

i need a new air filter but that shouldn't be the reason why my atv is running sooo lean. possibly rich but not lean, right?


thanks for your helps! =)

 

[coolguy147]

Re: atv help? 1999 suzuki 250 atv.

yay!!!! i got it alll fixed up! i adjusted the valves over again and that helped. not sure what i did but i adjusted them dead on some how. it's idling nice and low and didn't stall! take off is good =)

i idled it for a good amount of time to make sure it was all good. i put the whole back fender on while it was idling.

soo happy =) thanks for your help guys!

 

[JRJ]

Re: atv help? 1999 suzuki 250 atv.

Congrats on getting it going, now have fun

 

[rbh]

Re: atv help? 1999 suzuki 250 atv.

Hey bud glad you got it going.
I have been on both sides of the fence one time they were so loose all you heard was TACK TACK TACK, what a pain to start, the other was ZERO + clearance, you could start the engine at 32-42 degreese but any warmer and the valves were open??????


(I didn't set them both times)
I do not trust shops to do a good job anymore!!!!!!

 

[coolguy147]

Re: atv help? 1999 suzuki 250 atv.

Hey bud glad you got it going.
I have been on both sides of the fence one time they were so loose all you heard was TACK TACK TACK, what a pain to start, the other was ZERO + clearance, you could start the engine at 32-42 degreese but any warmer and the valves were open??????


(I didn't set them both times)
I do not trust shops to do a good job anymore!!!!!!

i hear clicking from the valve cover but i think it's normal on an atv seeing as it's air cooled and a single cylinder. i just started it up cold today, it started up without throttle but i gave it some to warm it up faster but it ran great.

shops just charge too much. i'm glad i got the experience =)

the loudest i hear the engine is when i'm going up hill slowly. the clicking is to a minimum and wouldn't call it excessive.

the shops around here are ok but being 16, i can't afford them

 

[coolguy147]

Re: atv help? 1999 suzuki 250 atv.

my carb adjustment is still 3 turns out though

 

[rbh]

Re: atv help? 1999 suzuki 250 atv.

YUP, thats the thing with setting valves, they have to be done when they are "cold".

The TACKING should go away, as the engine heats up everything is expanding.

Mikuni carb???? air/fuel mixture screw??

 

[bigdee]

Re: atv help? 1999 suzuki 250 atv.

i need a new air filter but that shouldn't be the reason why my atv is running sooo lean. possibly rich but not lean, right?


thanks for your helps! =)

These things will not run correctly without the air filter AND filter housing in place.......I found out the hard way

 

[coolguy147]

Re: atv help? 1999 suzuki 250 atv.

These things will not run correctly without the air filter AND filter housing in place.......I found out the hard way

my air filter is in there lol! it just has mold spots and doesn't come back up in spots lol

it sounds pretty much the same cold and warm?

i waited 24 hours for it to cool down before i set them =)

yes, it has a mikuni carb and the carb has a air/fuel mixture adjustment

 

[coolguy147]

Re: atv help? 1999 suzuki 250 atv.

it tacking is not excessive what so over but i still know it's there?

 

[fisherguy123]

Re: atv help? 1999 suzuki 250 atv.

I got the same bike up here in the north, about 8000kms on it and she ticks pretty good for about 5 min `s until good and warm so I never had an issue with it....I think its quite normal for that motor.

 

[coolguy147]

Re: atv help? 1999 suzuki 250 atv.

I got the same bike up here in the north, about 8000kms on it and she ticks pretty good for about 5 min `s until good and warm so I never had an issue with it....I think its quite normal for that motor.

yeah, i defiantly think it's normal for my motor.

give it some throttle when cold, warmed up it idles nice and low =)