Good Day,

Was out riding this weekend with my 04 DS650 Baja, Here is what happened. I just got the quad, Have taken it out 3 times, It has ran amazing for those 3 times but yesterday it all changed. To start it off I catwalked for a few seconds but i gave it to much gas and it ended up on its grab bar, I simply pushed it back down, turned the fuel off and cleaned the gas out of the air box. It still ran good, we went about 10KM, I was on a long straight road and pinned it, I was in 5th Gear and it lost all power, I let go of the gas and it stalled. For a little bit the quad would start, make it a few hundred meters then die. I found out my fuel was on reserve and not on. I switched it to the on position but same thing keeps happening.

After 5-10 minutes it will start and ride good for about 500 meters then it starts to bog out and then dies. I cannot figure it out. Im going to end up cleaning the carb, changing the oil, flushing the gas but i was wondering if any mechanically inclined people may know what this is.

I dont understand 100% how the reserve works but my thoughts maybe the jets are clogged from using the gas in the reserve?

Any thoughts?

 

I may have found the problem today, The hose that goes from the carb to the engine was cracked, thus probably affecting air/fuel ratio allowing more air then need to flow through

 

That has a WHOLE LOT to do with your issue! Have to replace that to diagnose anything else but all fo that air, and dirt getting in through there is not good.

Welcome to the forum by the way. Seems that you have a little bit of troubleshooting skills. Will come in handy s these machines are aging.

 

A lean mixture typically won't rob power, though... I would check the compression and/or do a leakdown test to be on the safe side.

 

Thanks for the tips. I sure hope it's nothing more then that as that hose is a cheap fix. Tearing the engine won't be. It was so weird tho how it happened all of a sudden while in 5th gear. It ran perfect before. I found this and it basically says what has happened to me.

2) Lean Mixtures means the carburetor is delivering too much air. Typical symptoms of a lean mixture are:

Backfires as the throttle is closed (primarily during coast-downs)

Lurching acceleration

White or light grey spark plugs

Requires excessive amounts of choke to run/start



These we the exact problems I had. It would backfire when coasting down. It would be jerky when accelerating. We will see..I will keep it updated

 

Ahhhh. It definitely was not that. The quad will start, Run for about 30 seconds and then bog out / stall. The odd time when it stalls it makes a terrible noise is the engine like something is getting engaged or disengaged, It does feel like the exhaust gets hot very fast but its hard to tell if I am making symptoms up now or its normal temp, I do not have a temp gun to get a reading but it gets warm fast.

This all started after taking the quad into 5th gear on a long straight road going pretty fast.

What would cause it to run for 30 seconds, stall then need a few minutes before it will start again?

-I did a half@$$ clean of the Carb, Could not remove Float Cover
-Flush the Gas system + clean gas filter
-Coolant level = Good
-Oil Level = Good


Could it be a bad piston or sound more like bad carb?

 

Try it with the gas cap loose. If it runs, then the vent line for the gas tank is pinched/clogged somewhere.

You should also check the float level. If the float is too low, it won't get enough gas to keep it running. I connected a foot long length of clear tubing (1/16 possibly?) to the drain at the bottom of the carb. With the petcock open and the clear hose looped up so the open end is higher than the carb itself, turn the drain screw on the bottom of the carb to open it up. Fuel should start to flow into the tube. The height of the fuel in the tube should be close to the gasket line of the carb bowl. If it's significantly lower, you need to pull the bowl and check the float level. Look in the OMR carb mods post for how to do this.

Also, the reserve setting on the petcock is a second tube where the opening is a little higher vertically than the tube in the main run positiion. BOth of these tubes will have "socks" on them that act as simple fuel filters. These can also get clogged up and starve the bike for fuel. Since you turned the bike on it's end, it's possible you loaded up the "socks" with dirt as well.

 

I'm with Papa. Check your float. The valve may be sticking or binding

 

So I thought I would take a wack at trying to clean the carb, After reading up and watching so videos I went at it, During removing the Float Bowl Cover, 2 Stubborn screws did not want to come out resulting in me stripping them. I ended up getting them off with a good set of pliers.

Upon removing the Bowl there was a fair amount of black/brown resin on the bottom. I removed all the jets and clean the path ways, When I was cleaning the "Hole" where the fuel first comes into the carb, This is what came out of the hole when cleaning it with a Q Tip.

I have yet to find out if this is the problem but from much advice from people they were telling me it sounds like the float was stuck, This gunk came out of the hole where the piece that opens and closes when the floats go up, I want to replace all screws on throttle cover and bowl cover with Hex Screws. So until then, We wait and see.

 

wow. That's scary looking. When I took my carb apart after 1st getting it, I just found some white, scaly residue, and a little bit of rust, even though the previous owner said the carb had been cleaned about 6 months prevoius. After reading around, I decided it was from using fuel that contained methanol. Since the bike sits around more than getting ridden, the higher water content that is present in methanol laced fuels causes these deposits. I went out and bought a container of Stabil methanol treatment that I add to the gas can when refilling it. The marine grade methanol treatment was on sale at the time, so that's what I bought. I haven't had an issue with the carb plugging up, but it's only been about 11 months since I started using the treatment. I think it's cheap insurance, especially if you live somewhere with high humidity.

I also made it a point to replace all of the o-rings when I had it open. It was a good idea, since most of them disentegrated with the slightest pressure when removing them. Cheap insurance once again. The o-rings cost me about $5 total.