I recently bought a 2003 650 Baja which was rode about 3 hours according to the owner. then put away in the garage. The thing looks brand new, not a scratch on the platics, bolts still shiny. I put in new plugs, battery, fuel lines. I also had installed a jet kit,pipe & K&N. Thing runs FAST! After its first really long hard day of riding it began to break up and the motor died. After a short rest it started up again, but ran lke crap. I was able to limp it home. I changed both plugs, one smells like gas. Now it will start after bout 5 minutes of cranking it, but will only run for about 2 seconds & die.

I have no idea what is wrong! I really know nothing about this rotax motor. Any advice would be great Thanks!

 

I would start by checking the compression and checking the spark. If the compression is low then you know where to start, if the compression is normal check to see if the spark is week. If the compression and spark are normal check to see if you are getting feul to the carb.

 

Hi Jersey, Welcome to the bomb site. It sounds like you have a vapor lock. Check your fuel cap to see if it breathes. Also under your stock fuel tank is a mile of breather hose, it is real comon for that to get pinched. Mine had the same problem, it was my fuel tank cap blow into it, it should be a oneway valve. Goodluck [img]i/expressions/face-icon-small-wink.gif[/img]

 

Welcome to the forums and where at in jersey are you located...What size jets did you install and did you also put a pilot jet...how did the bike run before these parts and are you running an open airbox.

 

No pinch in the fuel line plus I just replaced that & the filter 1 week ago. I did not do the jet install, Its a dynojet I think its got the 180 jet in there now. It ran top notch after the install. It actually ran strong the whole time I was riding (about 3 hours, with breaks ever 1/2 hour or so). Fuel cap is on good. Just changed plugs to be sure and still wont start/run.

No my airbox is closed up still, dispite others advice. The K&N Filter & Precharger are 1 week old. I also just put on a new FMF Core 4 pipe.

Bombrider04- Burlington County off of Rt 70

 

So which twp would that make you because you are really close to around where I am at...To me the problem seems like its your carb or you ran it out of gas...the ventline has been a problem in the past with the ds's so I just cut mine down...It sounds like you are getting spark, but what color were your plugs?

 

Bombrider04- Pemberton Twp.

The plugs were a week old too. The top plug was black about 1 inch up, but not really fouled outby any means. the side plug was only black about 1/2 inch up, but smelled like gas. Like I said I don't know too much about this motor and am pretty new to the sport so my knowledge is not the best. The fuel is good to go. Same tank it was on before with no problems. Any ideas?

 

Like I said, check the compression to get those possibilities out of the way. Next check your spark, I recently had a problem with one of my bikes. The magnets in the fly wheel came out of phase and I was not getting very good spark. It would run for a few seconds and shut off. So test your compression and then test your spark.

You can get a compression tester at harbor freight for under $20. You can test you spark by pulling the plug and grounding it to the frame and turn the motor over, the spark should be bright and visible if it is hard to see and barely visible I would start digging deeper. It could be as simple as your kill switch might be bad, or a bad ground on your cdi box. If it is easy disconnect your kill switch and see if it starts. At this point for you it is process of elimination, take it one step at a time.

 

The reason I asked about your plugs was to see if the jetting was on and you weren't running too lean or rich, I have a 185 in currently with a full system and no lid with a K&N...the rectifiers tend to have problems on the ds so do check the spark, but from sitting a while and if he barely ran it you problably have junk stuck in your carb or the diaphragm of the carb is screwed up.

 

Bomb650NJ...

If you don't have one yet pick up a Battery Tender that puts a trickle charge on the battery and goes to "Float" when fully charged. Even though you just put a battery on I'm almost certain it didn't come fully charged...most of them don't. You'll be suprised to find that the DS does not fair well with a low charge.

Getting to know the components of your machine is vital unless you just like to shell out lots of money to the dealerships and most of them won't ever treat you right. The carb should be one of your first adventures in learning...give yourself a saturday and start by loosening up the boots at either end of the carb so you can twist it and pull the cover on the passenger side of the carb (3 screws) and get the throttle cable free. Remove the carb from the DS and change out the bottom screws to stainless steel hex caps that you use an allen wrench on--makes jetting a bit easier. Also do yourself a favor and burn a copy of OMR's, "Stock Carb Mods"...I did the mods friday night and took her for a spin today...WOW! What a difference!

There is a ton of good information in these threads so search away and do like I do...copy and paste into word documents for later reference...

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