Yamaha Engine cutting out at RPM???

[dnf736]

Plugged vent line? Fuel cell foam? Loose/bad connection? Loose screw in the drivers seat?

 

[JoeyD23]

for sure the screw is loose in the drivers seat! haahha

What vent line are you refering too doug?

Loose or bad connection possibly but I wont even know where to start?

 

[dnf736]

Fuel tank vent line. Doubt thats your trouble but check it anyway, maybe something came loose and it kinked.

Loose/bad/shorted connection, follow the harness, anywhere theres a connection, clamp, or zip tie theres a potential trouble spot. Push, pull, wiggle....

 

[JoeyD23]

yep...gonna be a painstaking gremlin to find if its the wiring....I may just have the whole car re wired at that point if I think its in the wiring.....lol

 

[s2k1]

Wise man's bet that the stator is fine. Reverse switch connection is 90% probability, plug cap issue is the remaining 9.9%, other is .1%.

 

[JoeyD23]

reverse switch connection is in the CDI Chris or where? pardon my stupidity...lol

 

[Wild Earp]

reverse switch connection is in the CDI Chris or where? pardon my stupidity...lol

right under the stock air filter box, drivers side - ground the wire that goes to the top of it to bypass it.

 

[JoeyD23]

hmm...I will check it out.....just splice a wire in and run it to the frame or something Ben?


WOW This was post 6000!!!

 

[Wild Earp]

hmm...I will check it out.....just splice a wire in and run it to the frame or something Ben?


WOW This was post 6000!!!

You can cut the stock terminal off, and put on a eyelet, and stick it under a bolt on the motor, or anywhere grounded. But your reverse light wont work any more.

 

[OLET]

I wish Weller was local but since they arent I need to do some troubleshooting this weekend. At RPM my motor wants to cough and cut out.....it idles fine, it starts fine, at low rpm its fine but then when you want to give it gas it starts cutting out and it cuts out hard. so here is what I have done so far:

-First I replaced the stock fuel pump with a new Weller Racing High Volume fuel system. New filter included. routed all lines correctly.

-The CDI I have is an older BRP Pro Comm CDI. I tried swapping it with a Pro Craft CDI and it had the same results. Tommorow I pick up a newer BRP Dynatek and will be running that from here on out.

-I pulled the carb apart and checked the float bowl tap, the needle, and made sure all the jets were clean and clear. same problem still. I then tried putting a fat jet in it....same problem so went back to the proper jet.

-I changed the spark plug although it had a brand new one in there. Same problem

-The motor dyno'd perfect. I took it to the desert and was running awesome, went through one big whoop section and this started happening???

What could it be? Rusty thinks maybe the stator is going out or is bad?

PLEASE HELP!

iI HAD THAT EXACT SAME PROBLEM AND IT WAS MY FUEL PUMP! YOU MAY HAVE A BUM PUMP!

 

[Wild Earp]

My cutting out problems (after replacing every other part of the fuel system) was fixed by replacing the carb (HSR45 with a FCR41). Not saying thats your problem, but in my case, thats what finally fixed it. (bobbling under full throttle left had turns).

 

[Wild Earp]

Joey, Ive got a spare high flow mikuni pump you can try out if you want. You can pick it up when you drop off those wheels!! HA HA HA

 

[OLET]

Joey, Ive got a spare high flow mikuni pump you can try out if you want. You can pick it up when you drop off those wheels!! HA HA HA

I WOULD DEFFINTLY TRY THAT! CHECK YOUR FLOATS AND YOUR MAIN JET, MAKE SURE ITS NOT LAYING IN THE BOTTOM OF THE BOWL! , YOU CAN ALSO CHECK YOUR STATOR WITH A VOLTOMETER. IN THAT FUEL PUMP THERE IS LIKE A THIN PEICE OFF PLASTIC THAT CAUSES VIBRATION , THEY CAN GO SO EASY!

 

[fyrfly6]

Having the same problem... Rebuilt the carb but no change. Gonna check the wiring now. Good Luck

 

[c&c rhino]

im with chris on this one. i always ground the reverse switch wire, i forget how it works but if something goes wrong with the switch the ignition goes in kind of a safety mode designed for limiting speed backing up, but then applies to an overall situation when the switch sticks or malfunctions. the tension wire in the cap that bites onto the threads sticking out of the plug can break, usually caused my the cap vibrating around because the rubber cam cover plug on the cap wasnt seated correctly.

 

[BOBONTHIS]

Good Luck on the fix. Sounds to be electrical now. Just Buy a TERYX.

 

[JoeyD23]

gonna try that reverse wire trick after replacing the CDI.

anyone got pics of a grounded reverse wire?

 

[c&c rhino]

single green and white wire. hard black plastic plug that connects to the switch has a 90 in it. any ground point.

 

[JoeyD23]

thanks Troy!

 

[ranchmkt]

That sucks Joey. I had the same problem over New Years but for me it was a bad fuel pump "I got lucky". If you need to rewire Chris turned me on to Marc at Wirefab he is just down the street from Chris in Ramona. Marc did a nice job on mine.