1996 ltf-259 QuadRunner Suzuki 2x4

History:

ATV was getting hard to start, and would not Idle. I let it sit too long and figured the carb was plugged. To start it I would have to open throttle and ecessively crank it.
I took it to the dealer to get serviced, after 10 hours of labor they got it working.(rebuilt carb..eh)

After a while it has progressively gotten worse, same thing, must open throttle it, cannot use choke, totally will not start if the choke is even slightly closed.

I replaced it with a hotter spark plug, it helped. 93 Octane helped as well.

...it finally just would NOT start, I decided to do my own work(still pissed about 10hrs of labor for carb service)

I found my Air tube from filter box to carb was half way off. So I assume there was dirt in carb, it must be plugged up. I rebuilt the carb, adjusted the float slightly, found a few pieces that were missing(a washer for the jet needle was not there)

Put it back together, would not start, I could ONLY get it started with starting fluid, and after it started, I had to keep the throttle at LEAST at half throttle it refused to idle.

I adjusted my valve lash, VALVES WERE WAY TOO TIGHT, so I put it back to factory specs.

I checked the spark, the plug-insulator was all black, but the spark was strong(white), replaced plug with original NGK.

still will not start... only starts with starting fluid and refuses to idle, choke kills motor.

-I ran a leak-down test, PASSED, less than 4% leakage.

-Checked my spark, white arc, but the plug got all black from only 5 minutes of running.

-checked vacuum lines.

-checked fuel pump,pumps fuel to carb just fine

-new air filter

So why isn't this thing starting right up? I got compression, fuel and spark, the last thing I thought is maybe my Ignition system is malfunctioning. Seems to be getting spark though.

 

I'll assume you've checked to be sure the float needle is not leaking and the float height is set correctly.
Mike

 

Yes during my carburator rebuild I put the float height back into specs according to the manual.

update: I got it started, what I did was I had the new spark plug in the engine and a spare connected to the spark plug wire grounded to the frame, I fully choked it, and cranked to double check my spark.

removed the new plug out of cylinder, it was wet, so reinstalled turned off choke, connected the plug wire and it started right up.

it would not idle until it was warmed up, I adjusted the idle speed screw then it would idle on the fast side, but died when I attempted to give it gas. So now at least found a way to get it started.

UPDATE: according to the manual I should have a FAT BLUE SPARK, I am just getting a white "lighting" spark, checked the coil, primary tested good, but secondary resistance check was WAY OFF.

I now suspect it is the coil. Secondary is reading at 192,000 Ohms!

 

Get yourself a simple spark gap tester, they are under $10 and see if the spark is hot enough to jump a 3/8" to 1/2" gap. The one I'm thinking of snaps in the plug cap and has a alligator clip to hook to the spark plug. Then you can check the spark cranking or running the engine and adjust the tester gap widder until it missfires.
Does sound like you have some carb troubles too, flooding or running rich
I did alot of fighting will my yfm80 and finally got it to run good but still was hard to start.
In the end the coils, all of them where out of spec on ohm readings. As a result the spark was weak, would only jump a 1/8 to 3/16" gap.
Just a thought.
Ken

 

Is your pilot jet needle set to spec?
Mike

 

Yeah Mike when I rebuilt the carb I put everything within specifications, I'm using a Clymer manual. Blew everything out with compressed air, cleaned with a toothbrush and choke cleaner,etc.

I had a missing piece(a washer guide for the jet needle) the float was 2mm out of spec, adjusted that. I used a new pilot jet needle so I set it to the manuals specification of 3 1/2 turns out. The shop just reused the bowl gasket and slapped on gasket sealer, had to clean that all up.

I paid a rookie at the Suzuki dealer 10 hrs. of labor to Spam wordSpam wordSpam word Spam wordSpam wordSpam word Spam wordSpam wordSpam word Spam wordSpam wordSpam word half assSpam wordSpam wordSpam word Spam wordSpam wordSpam word Spam wordSpam wordSpam word Spam wordSpam wordSpam word fix my carburator. Had I know it would take them THAT long, I would have asked for a NEW carb, and be 50 bucks richer.

So I will order a new coil, I tested it warm as the manual said, and it read 190,000 ohms, that is NINE TIMES the max allowed.(20,000 ohms max)

I doubled checked my math/humanity for errors, and that is what it is, the primary coil was good, I'm guessing it got too hot being a air cooled ATV, or someone tried to start it with the plug wire disconnected.

So now I will order this part, perhaps test the old part with a spark tester, and see what happens, stay tuned!

 

I have a '96 250 4X4 Suzi I bought used about 8 yrs ago and it never wanted to start much below 25*F. I checked comp and it was right at the minimum, so finally last fall decided to do a top end on it. The funny part was when I got the jug and piston out, I could still see the crosshatch in the bore and the piston had a few very shallow scratches on the skirt. I figure someone got it too hot and took the temper out of the rings. I honed the bore good. Got that done and everythings fine except it always seemed to have a rich idle ever since I bought it. I'd had the carb out yrs ago, cleaned and set everything to spec but didn't change any carb parts. So this winter while plowing snow, it got so's it would flood and die if it idled more than 10 sec. Out comes the carb, put a new kit in. Lo and behold it idles better than it has since I bought it,LOL!! The float needle must have had a slight leak all along.
I also have a Clymers manual for mine. Best money I've ever spent!!
If the new coil doesn't fix your's I'm still putting money on the carb.
Mike

 

Simple fix for those pesky leaky float needles... Take the gas line off at the tank and insert an airchuck and let loose with 40-60 psi (or more). Turn your head because gas will go everywhere! Works everytime I've tried it.

 

UPDATE:

I installed the new coil, fat blue spark.

Started it up and still the same thing, the sparkplug is ALL BLACK and wet, the exhaust is blue, I'm running WAY rich.

I pulled off the carb, gas everywhere in air tube. Flipped the carb over opened up and adjusted float again, then I broke one of the two float pin supports!

So I'm waiting 24 hours for the J.B. weld to cure before I can continue.

For good measure I adj the float to the max tolerance,(leanest) and adj. my idle screw from 3 1/2 to 3 turns out.

Tomorrow I'll slap it back together and do what Randy(above me) said, seat that needle!

It's obviously a carb problem. I'll post back.

 

So I just put it back together, shot compressed air into the fuel line. and then attempted to start it, it started! However it was running rich still.

I adjusted the idle speed screw and the pilot jet screw. I have gotten it to idle, and had to turn in the pilot screw in a good 1 turn.

So now it idles and starts easier, the choke is working, if I choke it a LITTLE it will increase rpms, a little more choke and it dies, this is when it's warmed up.

it has a SLIGHT hesitation when you throttle it from Idle. It bogs down that means it is rich somewhere along the fuel curve...

Do I need to adjust my E-clip on my needle down one notch...try setting it one notch lower?

The needle has 5 grooves, #1 at the top, to #5 closest to the needle tip. I have the needle in the middle #3.

Putting the E clip towards the top leans the mixture because a thicker portion of the needle is blocking fuel flow through the needle jet, right?

Placing the E clip closer to the tip en-richens the mixture by pulling the needle further from the needle jet, exposing a thinner portion to allow more fuel flow, do I have this right?