hey guys im lookin for some help. i recently aquired a 93 yamaha vxr with 701. picked it up for free. the main reason i got it is to do a swap into a stand up. now for the problem. i tore the carb down to clean it. everything looked ok. when i put it back on it still wont run. i can dump a lil gas in the carb it will fire and run. the weird part is im not getting fuel out of the feed line. anyone got any ideas?? the only guess i have is one the diaphram that controls the needle valve is kinda stiff. could that be a cause? any help appreciated.
Other carb problems
- Thread starter hasson13
- Start date
Nuklear6
I Dream 10' Surf!
after you check all the things water nut mentioned, make sure to check the fuel switch for any issues or leaks. can be a def prob on older yamahas (if your still running it).
Ok here's the skinny... You said you connected the line straight from the tank to the carb and it still isn't drawing fuel. Try sealing the top of the carb with your hand and crank it for a few seconds. If it still won't pull fuel, your lines are hooked up wrong or they're clogged. It's not rocket science, provided the carb has all the parts in it (in good condition or not). The pressure generated from the engine turning forces fuel through the carb. The only other thing that could be an issue is maybe the tank vent is backwards but I highly doubt it because that just wouldn't let it run very long.
If this doesn't fix it, snap a picture of your setup.
If this doesn't fix it, snap a picture of your setup.
If you haven't already double check everything is where its supposed to be(http://216.37.204.203/yamaha_OEM/YamahaPWC.asp?Type=13&A=38&B=1), did you pull out your jets to make sure they were clear? as well as your needle & seat? double check your circuits makes sure they are clean and clear, also make sure your fuel pick ups aren't kinked or plugged
Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
drip a few squirts of gas down in the carb and get the motor to fire off. I have seen this and done it to get the carb to start pumping correctly.
That is possible but you'll still be able to run the engine with a completely sealed tank or a completely open tank...it just won't rev very well with an open tank and it'll only run for a short time (more than 5-10 seconds though) in a completely sealed tank.
Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
Unless the fuel turned to a gel, there is nothing to mess up the pickups. Take 2 pieces of fuel line, get a cup of gas, Stick one hose to the intake side of your carb, connect the other to the return side. Place the intake side into the cup, and the return side hold at the edge of the cup. Try and crank the ski, see if the carb(s) are trying to actually pump fuel. I am going to guess that you have an issue with the fuel pump side of your carb. Check your pulse line hose, make sure it is not split or leaking.
got it to run on its own power today. had to completley seal off carb intake to get fuel to carb. after that it was good. however i believe the carb does need a rebuild. it will idle with the choke closed but only for about 30-45 seconds then it acts like it runs out of fuel. if i start and work the choke and give it about quarter throtlle i can keep it running. the main problem with the carb(i think at least) is the jet side diaphram that controls the needle valve. if i hold it up to the light i can see light through some spots where the material is gone and its just the screen. it will also leak fuel out of the breather hole on the cover when given hard throttle. oh and it wont rev past quater throttle. so my guess is its time for a rebuild
Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
jeeez. Rebuild the carb.
Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
contact Jetmaniac, he will have some. Great guy to deal with.
jetski9010
Team RTYD
- Location
- Lancaster PA
If you dont feel 100% like you know what your doing rebuilding it just send it off to make sure it get rebuilt right then you wont be on the side of the lake all summer. http://www.jetskisolutions.com/p42_carburetor_rebuilding_services.html