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jmlloar
jmlloar, Motorcycle Mechanic
Category: Motorcycle
Satisfied Customers: 73
Experience:  Suzuki service pro certified multiple Yamaha and Kawasaki certifications
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timing..fuel tank..IDLES FINE, but when you throttle it up, it cuts

Customer Question

1995 yamaha big bear 350, good compression 150#, carb. is good, timing is dead on, and a new coil. The fuel tank has been cleand and draind twice, to put new gas in it. IDLES FINE, but when you throttle it up, it cuts out and eventually dies, it'll start right up. Seems to be constantly intermitant. Could this be electrical, or what?
Submitted: 4 years ago.
Category: Motorcycle
Expert:  jmlloar replied 4 years ago.

jmlloar :

does it completely die or just pop and spit and carry on

jmlloar :

Hello, are you there?

Customer:

Dies, will idle if left unthrottled.

jmlloar :

Only electrical problem on yamaha that is assosiated with this typr problem is the park brake switch

Customer:

sometimes if throttled slow it spits and sputers before die

jmlloar :

Sounds more like carb problem

jmlloar :

first easy check, is intake boot cracked? Pull on carb and look for cracks

Customer:

I've been through this carb three times and it's all there, clean and all ports are open. raised the float leaval, lowered the float, all the same results. Now cracks in intake boot.

jmlloar :

is this the cv carb with round top and spring on top of slide?

Customer:

no round top, spring under plate on top of slid

jmlloar :

does slide move freely up and down in carb with your finger

Customer:

Yes

jmlloar :

look very carefully for crak or tear in slide diaphram

Customer:

none. one other ?, should the flywheel be in oil bath?

jmlloar :

yes

Customer:

Where is the pick up on this?

jmlloar :

You can check switch for p brake, it very seldom causes a stall but it does keep engine from reving

jmlloar :

pickup there is actually 2

jmlloar :

both are with stator in the flywheel side

Customer:

Do these ever cause problems?

jmlloar :

only ever seen a no start from pick up

Customer:

Understand. Have You ever known any problems like this that wasn the carb.?

jmlloar :

test p brake switch and let me know, its the small switch on left handlebar lever, first try pushing out on brake lever and reving engine

jmlloar :

This is a bullet froff engine and very few problems other than neglect I have seen

jmlloar :

bullet proof

Customer:

How can I get back to this after checking it out.

jmlloar :

you will get an email link, and you should have a my questions link when logged in to the site

Customer:

Thanks, XXXXX XXXXX do that now.

jmlloar :

ok

jmlloar and other Motorcycle Specialists are ready to help you
Customer: replied 4 years ago.
Relist: Incomplete answer.
Customer: replied 4 years ago.
Hello, are you there? Do You want to know what it was?
Expert:  jmlloar replied 4 years ago.
know what what was?
Customer: replied 4 years ago.
Sorry, my bad. The carb was good, but I had a vet tube patially blocked. Dam those mud dobbers.
Expert:  jmlloar replied 4 years ago.

Pretty common

 

Good way to solve that is by using a fish aquarium air end. The one that is like a cylinder shaped tube that hooks onto the end of the air pump line. Attach it to the end of your carb breather and it will help keep them out. An in line fuel filter works almost as well.