I made it worse!

[[email protected]]

This is not vmax related hence, its in the burnout pit.

Last summer I sold my CR500 and bought a couple quads. One new sportsman 570 and one used Grizzly 450.

The grizz got all the fluids changed, greased, filter clean, new brake pads, etc... All was well with my used ATV purchase. However, it does have a bit of an issue holding an idle. Sometimes it needs choke to stay running, just a touch. But ran fine.

It sat in the garage all winter. I noticed a differential seal leaking so, I pulled the axles and replaced the seals on Saturday. Took it for a spin and all was good but I was still bothered by this idle issue.

I decided to dig in. I pulled the carb and checked the valves. Valve lash was perfect. The carb had a touch of dirt in it but not much. I didn't tear it 100% down. I pulled the jets in the bowl and both diaphragms. Cleaned it all up and put it back together.

I figured I would pull it out of the garage and test it out. It didn't want to fire up. Once it did, it barely ran. It spit and sputtered and didn't want to stay running. I had to hold the throttle to keep it going. As soon as I let off, it died. It was a pig to fire up again. I got it going and the same thing. Just doesn't want to run. I let off and it died. It didn't want to start so, I just gave up and wheeled it back in.

I tore it apart again. Pulled the carb again to double check I didn't F*&K anything up. All looks perfectly fine in there. I have no idea what the hell is wrong. Almost feels like an electrical issue but who know. I was pushing and pulling wires and plastic to do the work. I'm a bit lost where to start.

Bottom line, I made it worse! Sometimes your better off just leaving **** alone. I hope I figure this out soon for 2 reasons.
1. Its bugging the **** out of me trying to figure out what the problem is.
2. We are going riding down HMT again in a couple weeks and I want to bring the grizz as a backup 'cause someone always breaks down.

Just venting. Thanks for stopping by :biglaugh:

 

[blaxmax]

Sounds like you got 1/2 through cleaning the carbs in my opinion. No offence.The subtle change and difference in the 2nd time you did the carbs sounds like the problem still lies in the carbs.

 

[Fire-medic]

I know it probably isn't the cause, but plugs are cheap, replace them (it?) and see if that makes a difference. I had one problem like that w/one of my KZ1000's, same thing, preventative maintenance, but it ran poorly, turned out to be a bad -new-plug. I was just so-locked-into thinking, "it's brand-new, that can't possibly be the cause!" However it was, and I had to enlist the help of my friend the professional mechanic to resolve the matter. You learn.

 

[caseyjones955]

If it sat for any length of time with ethanol tainted fuel it could need a complete dissassembly, cleaning, inspection (especially rubber bits exposed to the fuel) and reassembly,

Assuming full of fresh fuel, fuel selector valve position and x2 on pinched tubes or wires during rreassembly. Not familiar with this model but some floats are susceptible to filling up with fuel if they fail. I hope ya get her sorted in time.

 

[[email protected]]

The carb is clean, for sure. All hoses are good and routed properly. I drained some fuel into a jar and its flowing out fast and it's clean.

Yesterday, I pulled the plug to turn the engine over in order to adjust the valves. It looked good. Low miles on it. Nice light tan color. I pulled the plug today and noticed that it was very black and wet.

Makes me think of a couple possibilities.

1. Getting too much fuel: No jets were changed. No major adjustments done so how would it get more fuel all of a sudden?

2. Bad spark: Not sure what would cause this. Could be the plug is bad, or a loose connection from moving things around.

I ordered a new o-ring for the emulsion tube in the carb. This one isn't cracked but was a bit hard. Might as well do it while it's off. Once I get that, I'll put a new plug in and give it a go.



Sent from my SM-G900V using Tapatalk

 

[dannymax]

Any chance of a vacuum leak Mike?

 

[blaxmax]

The carb is clean, for sure. All hoses are good and routed properly. I drained some fuel into a jar and its flowing out fast and it's clean.

Yesterday, I pulled the plug to turn the engine over in order to adjust the valves. It looked good. Low miles on it. Nice light tan color. I pulled the plug today and noticed that it was very black and wet.

Makes me think of a couple possibilities.

1. Getting too much fuel: No jets were changed. No major adjustments done so how would it get more fuel all of a sudden?

2. Bad spark: Not sure what would cause this. Could be the plug is bad, or a loose connection from moving things around.

I ordered a new o-ring for the emulsion tube in the carb. This one isn't cracked but was a bit hard. Might as well do it while it's off. Once I get that, I'll put a new plug in and give it a go.



Sent from my SM-G900V using Tapatalk

1. Getting too much fuel---check for wet plugs2. Bad spark---Check for a fat spark

 

[[email protected]]

Any chance of a vacuum leak Mike?

Always a chance Dan. I'll check for leaks once it's back together.

1. Getting too much fuel---check for wet plugs2. Bad spark---Check for a fat spark

The plug is definitely wet. It ran yesterday (barely)for just a couple minutes and this was enough to change the plug from nice and tan to black and dripping when I pulled it today.



Sent from my SM-G900V using Tapatalk

 

[[email protected]]

I picked up my new o-rings from the local shop and installed them.

Installed a new spark plug.

Put it all together and started it.

It started right up but ran like crap. Won't idle at all. Will only run if I hold the throttle open. As soon as I let off it dies.

Pulled the plug and it is black after running for a couple minutes.

It ran good before a carb clean and valve lash check. It barely runs now. AARRRGH!!

Had company tonight so I didn't spend much time on it. Will dig a little deeper tomorrow.


Sent from my SM-G900V using Tapatalk

 

[blaxmax]

Either dumping gas somewhere or not getting enough fire. Did you try rebuilding the spark plug wire?I still say the carb though.

 

[cyclejohn]

Just out of curiosity, you do have the filtered air inlet boot attached to the carbs while doing this testing?

For whatever reason, ATVs like to have that restriction in place to run/idle properly.


Just curious,
John

 

[[email protected]]

Just out of curiosity, you do have the filtered air inlet boot attached to the carbs while doing this testing?

For whatever reason, ATVs like to have that restriction in place to run/idle properly.


Just curious,
John

Yes. The intake ducting, airbox, and air filter are in place.

 

[diggerzmound]

Pop the air cleaner out and let it run, if its better its too rich.

These carbs are sensitive to float level, if you bumped or adjusted the float you may have the level too high.

 

[Barry barker]

My thoughts exactly, I had a Suzuki ATV that i rebuilt for a friend(they bring them to me once they have screwed everything up). That Mikuni carb had a float spec of say 16mm plus or minus 1mm. I ended up with the float set at about 11mm and it ran like a top. Before that way to rich, wouldn't idle. Yes I had to remove the carb 4 times to finally get a float level that would run correctly. Everytime i lowered the float(less fuel level) it ran better. It's still running great and it's been about 6 months. Good Luck

 

[[email protected]]

I got a chance to mess around again last night. I disassembled the carb to triple check. Cleaned it again very thoroughly.

Checked the boots again.

Pulled the airbox to check the wiring surrounding it and under it since I removed it the first time I worked on it. Cleaned connectors.

Double checked valve lash.

Rigged up a spark tester. I snapped the ground strap off a plug. Hose clamped a wire to the threads. Bolted the wire to the frame. Plugged it into the cap. Spark was questionable. Mostly blue. Some yellow.

Started it up and it runs like crap.

Had a friend stop by after work today. Hung out a bit. Had some drinks and dimner. Got to BS'ING about the quad. Went in the garage and had him wiggle the spark plug lead while I kept it running. At one point, it smoothed out and ran perfect. This leads me to believe it's a coil/lead issue. I'm not sure if the wire is replaceable like on the vmax. Might have to spring for the whole deal. I will try cleaning the coil ground and cutting back the plug wire before ordering parts.

Sent from my SM-G900V using Tapatalk

 

[blaxmax]

Good luck, i hope you've found it.

 

[[email protected]]

I bought a used, OEM carb off ebay for a decent price.
It was filthy.
I cleaned it in the slop sink here at work. Took it all apart cleaned all the jets and passages. Cleaned up the slide. Drilled out the plug covering the AF screw. Set it.

Took it home, threw it on the quad and it runs like a champ.

YEA! unk:

Now I am severely bent on trying to figure out what is wrong with my original carb. It was working OK before I cleaned it. Ran for **** afterwards. All jets went back as they should. The diaphragm and coasting enrichener were removed before the cleaning. Cleaning was done with a can of carb clean and my air compressor. I used the same method to clean the replacement carb. Put them both back together the same way but the original just doesn't work.

The original was running super rich. I expected an ignition problem (weak spark) because I was so sure the carb was good. Obviously NOT the case. I can't quite think of anything that would make a carb go rich after a good cleaning other than a choke issue. I disconnected the choke cable from the plunger to make sure the plunger wasn't being pulled into choke position on one of my test runs and it made no difference. I am a bit lost on this one.

Anyways, it works!

 

[blaxmax]

Good news Mike, I walked through a junkyard when I was younger than 10 and saw a mound of quadrojets by the back door of a shop. Asked my father "whats that"? He said they are carbs. I ask what was wrong with them and he said "no one knows." That is when I started working on them.