Fuel issue

1390 Views 16 Replies 4 Participants Last post by Shawnmills705, 10 mo ago

Shawnmills705

Discussion Starter · 12 mo ago

Hey guys, new here. Im working on a king quad 300 for a friend. It idles but want to stall when you hit the throttle, no difference choke on or off. Carb has been through but not by myself. What i have found which i find very odd is the thing runs just the same even with the gas line disconnected from the carb and dumping into a water bottle, it dies as soon as i pull the fuel pump vacuum line from the carb. The fuel output from the fuel line is minimal. To me the pump is bad and the vacuum is somehow sucking enough through it to make it run. Thoughts?

1 - 17 of 17 Posts

ajl719

· #2 · 12 mo ago

First off, to properly guide you in the right direction we’ll need to know the year of your 300. And welcome to the Forum.

Shawnmills705

Discussion Starter · #3 · 12 mo ago

ajl719 said:
First off, to properly guide you in the right direction we’ll need to know the year of your 300. And welcome to the Forum.

I have no idea of the year and not sure where to find it on the frame on these

ajl719

· #4 · 12 mo ago

Go to the back of the bike, you’ll see two vertical downtubes. Now take a look at the left downtube, you see a small welded tag with a mixture of letters and numbers facing towards the the inside of the left rear tire. This here is your 17 digit vin#. Post up your vin# and one of us will help you decode it to see what model you have.

Reactions: 1

Shawnmills705

Discussion Starter · #5 · 12 mo ago

Tire Automotive tire Tread Sleeve Wood

See less See more

ajl719

· #6 · 12 mo ago

Your bike’s a ‘97 per the tenth digit in your Vin#. Do you have any identifiable markings on your bike as to what model it is..? Like Quadrunner or King Quad..?

Shawnmills705

Discussion Starter · #7 · 12 mo ago

Stickers are all peeled, king quad 300 as per the owner

texas123

· #8 · 12 mo ago

I'd just rebuild the carb, add fresh fuel, spark plug, diff fluid & check/change all the fluids (like I do with all new bikes), grease it up and whatever else it needs. Clean it by hand; that way you'll find any loose grounds, connections, hoses, then take all the plastics off & check everything...
Then I'd start troubleshooting. It may be several things, but you may not know without setting a baseline.
I just got a 3 wheeler running after it sat & was covered in 1" of dust for the last 20 years by doing this. Here it as 2 days later. I think the dirt protected it to be honest.

Tire Wheel Land vehicle Vehicle Light

See less See more

Reactions: 2

Shawnmills705

Discussion Starter · #9 · 11 mo ago

Went through carb, found a few questionable things so took care of them. Seems to be flooding itself, it will run great for 10-15 seconds and sputters and stalls and wont restart right away unless i hold it wot. I verified float height, its bang on, needle valve is nice and clean

Shawnmills705

Discussion Starter · #10 · 11 mo ago

Another update, i tested needle valve with the carb bowl off and a bottle with gas connected to the inlet, gas leaked passed the inlet body. It seems to be coming from around the valve body, dried up o-ring i assume. Ordered a full carb kit, will just put everything new.

Shawnmills705

Discussion Starter · #11 · 11 mo ago

Well the only thing the carb kit fixed is the flodding, idles great and thats it lol. This ones a head scratcher for me. I have a short video of what its doing but its too large to atratch

ajl719

· #12 · 11 mo ago

Have you checked the fuel petcock to see if it might be the source of your issue..? When the vacuum operated fuel petcocks go bad they tend to leak fuel through the vacuum line. Thus causing hesitation, stalling, lack of power, and sometimes backfiring, etc.

Shawnmills705

Discussion Starter · #13 · 11 mo ago

Ya i verified, no fuel in the vacuum line for the petcock. I also completely eliminated the the gas tank setup by just using gravity fed bottle connected directly to the carb, no change.

Shawnmills705

Discussion Starter · #14 · 11 mo ago

Turns out i think ive been chasing a non fuel issue. Think it might be the regularor/rectifier. With lights off its charging over 15v at idle, jumps to 17-18 with the blip of the throttle. With lights on it idles a more normal 14v but will still jump to 18 when hitting throttle. Any way to confirm its the issue before replacing?

ajl719

· #15 · 11 mo ago

hardwood

· #16 · 11 mo ago

I have experince with this issue. When the regulator goes bad there could be melt down under the front fender. Scary. Replace with RM Stator asap.

Shawnmills705

Discussion Starter · #17 · 10 mo ago

Update for anyone searching in the future, new voltage regulator fixed the issue. Thanks everyone for all the input, great bunch here

1 - 17 of 17 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.