• Welcome to the Two Wheeled Texans community! Feel free to hang out and lurk as long as you like. However, we would like to encourage you to register so that you can join the community and use the numerous features on the site. After registering, don't forget to post up an introduction!

Petcock ON, fuel overflows carb

Monica

0
Forum Supporter
Joined
Oct 4, 2009
Messages
1,439
Reaction score
1,141
Location
Texas
Installed a new VM24 from Niche. When I turn the fuel petcock to ON, fuel flows out the bottom tubes. What do I need to adjust?

For grins I turned the bike on and it started right away. I left the petcock OFF so it would use the fuel in the carb. It did and died when it ran out, as expected.

Anyway, in the garage now. What can I do to fix this? On a '03 TTR125LE.

Thanks

Edit:
Pulled the bowl off, poked at the float, emptied the carb, put it all back together and back on the bike. Turned petcock on while holding the bike upright and it did just fine, no overflow. Put the bike back on the kick stand, played w the petcock and it overflowed fuel again. Turned it OFF. I don't know.
 
Last edited:
It is either a stuck float letting gas rise to hi and out the overflow. Or the float is set too high. And same result.
First try tapping on the float bowl and see if it stops. If yes, it's fixed.
Most likely though the float tab needs to be bent a little (removal required) set the float to shut off sooner. Blowing in the fuel inlet hose while raising the float bowl will let you see where it shuts off.
It could be a piece of dirt in the little shut off valve that the float works. But I assume you cleaned it before you mounted the carb.
Dried float needle rubber is also possible but not probable since I think you said it was new...
But as you can tell, it all revolves around the float area.
 
Last edited:
Thanks Jim. I will check the float level.
I put everything away for the night, tired of smelling gasoline lol Will give it another go tomorrow.
Going to study some diagrams/vids and photos for a bit so I can rock n roll when I tear into it again. I'm not familiar enough to be comfortable with all the parts yet. I don't like fumbling through lol
 
Last edited:
Here is a video on it and there are several more on youtube:
[ame="https://www.youtube.com/watch?v=Vhej6IZWsXE"]https://www.youtube.com/watch?v=Vhej6IZWsXE[/ame]
 
You're thinking along the right lines girl. I have seen floats that we're full of gas, instead of air. ( a leaking seam or a hole in the float). I appulade your effort.
 
Installed a new VM24 from Niche.
So something allowing fuel to continue into the bowl and then overflow.
On a New carb never been wet...Remove bowl and check float height if correct, move on, if not but close, adjust and move on.
Then Id look at the float needle and seat, check for trash in the seat, pull the seat and make sure it has an o ring and that it is not damaged (nicked, torn)
Shake the float, does it slosh? If so its leaking not likely , but manufacturing mistakes happen.

  1. Float height
  2. Trash in needle / seat
  3. Seat o ring missing or damaged
  4. Float damged
 
did you connect the fuel line to the metal fitting pointing straight up or to the black plastic fitting that is at a 90* angle?
 
I attached the fuel line to the inlet on top. I ran the hose up and around the carb. Otherwise it had to do a hard 90* that kinked the hose a little. Then it goes to the inline filter and then the petcock.

EMarquez, appreciate the run down list. I will check each.

Looks at vids last night, thought about it this morning. The more I read yalls advice here, I missed something simple. I kinda feel dumb already for when I fix it :lol2:
 

Attachments

  • carb inlet.jpg
    carb inlet.jpg
    27.7 KB · Views: 181
  • carb right.jpg
    carb right.jpg
    43.9 KB · Views: 190
  • carb left.jpg
    carb left.jpg
    40.5 KB · Views: 188
I attached the fuel line to the inlet on top. I ran the hose up and around the carb. Otherwise it had to do a hard 90* that kinked the hose a little. Then it goes to the inline filter and then the petcock.

EMarquez, appreciate the run down list. I will check each.

Looks at vids last night, thought about it this morning. The more I read yalls advice here, I missed something simple. I kinda feel dumb already for when I fix it :lol2:

Yep, looks like it is attached to the vent, and not the actual fuel inlet. Which is usually a 90 on the side.
Probably the black thing that is barely visible in the picture that shows the fuel filter is the inlet.
The place you have it looks to be a vent that should have a T on it.
You can also loot at the OEM parts list on RockyMountain's website to see the layout.

But you also added that it leaks when it when it is leaned over. that usually also means the float is set to hi, and letting in too much gas so when it is leaned over that it goes out the overflow tube.
So it could be both,, mounted in the wrong place and the float needing adjustment.

good luck
 
Last edited:
Huh.... lol


The black thing is this 90* here
mikuni-vm24-round-slide-24mm-carburetor-4c8.jpg
 
You have it connected up correctly, as stated the black thing in Monica's picture is a vent/overflow outlet NOT a fuel inlet!! You have a sticking float valve or the float height is not set correctly.

Gary
 
"sticking float valve"

It is a brand new carb.
But the carb came "pre jetted" someone has been into that carb before it left the retailer. So bent tab on the needle contact point, bent pivot pin causing the float to stick are possible..

The only time I have ever seen a "sticking float valve" is one that has build up from crappy or old gas, or that was assembled incorrectly. incorrect parts.


In the many dozens of carbs I clean every year (11 Mikuni BS28's, 6 Mikuni 26mm in the last 3 weeks), overflowing float bowls are 99% of the time caused but debris in the needle/ seat (dried up crappy gas crud) or damaged / old hard, shrunk seat O ring. Rarely do I find a needle seat damaged or worn to the point of leaking fuel. And I really can not remember the last time I found a float "sticking" other than because it was dirty.

Good diag means no skipping a possible cause..so I love that folks have suggested to check for a "stuck" float...Id just not get ...well stuck on that as a cause.
 
I haven't had the chance to get into it. Soon as I can (smell like gas for a while) I'll get the carb off. Hopefully have word soon.

Need to get this wrapped up and get the bike to the shop for the Rekluse install. The new bottle jack arrived for the mx hauler. I'm running behind.
 
I haven't had the chance to get into it. Soon as I can (smell like gas for a while) I'll get the carb off. Hopefully have word soon.

Need to get this wrapped up and get the bike to the shop for the Rekluse install. The new bottle jack arrived for the mx hauler. I'm running behind.

Where in Texas are you? If you are anywhere near McKinney (North of Dallas) I have a full workshop and would be happy to help you sort it out.

Gary
 
Gary that offer is much appreciated but I'm definitely not close enough to take you up on it.
 
Last edited:
Pulled the carb off, pulled the bowl, float and needles. Gave everything a good cleaning w carb spray. Blew through the fuel inlet, played with the floats, watched/heard the needle close. Pulled the calipers out, but before messing with the float level tab I decided to stick it back on and see if it'd work right (I put my faith in Niche that out of the many of these carbs they build that they knew what they were doing setting it up).

Well, it worked. I buttoned it up and left it. So far, no overflow. Guess there was some debris that did not allow the needle to close up properly.

I'll watch it but hopefully it's good to go now.

See, like I said, something simple I missed :doh: :lol2:

All excited, I got it loaded and drove over to the shop to drop it off for the Rekluse install...and they were closed :haha::argh:

I appreciate the guidance :chug:
 
Glad you got it fixed. Why are you putting in a recluse before you ride it ?
 
Glad you got it fixed. Why are you putting in a recluse before you ride it ?

Thanks.

Only have use of my right hand. In lieu of moving controls over figured I'd take advantage of the Rekluse and see how it goes.
 
I hope you like the recluse, they do drag a bit when stationary, so you need to keep some pressure on the front or rear brake to prevent the bike from creeping forward, but they do work well. I was going to ask why you don’t fit it yourself as they are an easy install, but I guess everything is more difficult when you only have one functioning hand. I hope you like the clutch and get plenty of riding done in 2018.

Best wishes.
 
I hope you like the recluse, they do drag a bit when stationary, so you need to keep some pressure on the front or rear brake to prevent the bike from creeping forward, but they do work well. I was going to ask why you don’t fit it yourself as they are an easy install, but I guess everything is more difficult when you only have one functioning hand. I hope you like the clutch and get plenty of riding done in 2018.

Best wishes.

That's what I keep hearing, they drag a bit so stay on the brake. I'll keep that in mind when I start on it.

Well, I usually install everything. On this I was concerned that I can't use my left hand for clutch in case it isn't set right. I can't clutch the bike, kinda worried the maiden test ride would be a spectacle.

At this point installing it on my own would be easier. My schedule is killing me. it's tough to get the bike loaded and over there during their working hours. My weekends are too short.


Last night I installed a different rear tail (the other didn't have the LP light so technically not legal, I'd get pulled over 'round here). The wiring is a mess under there. I'll eventually need to redo all of it at some point. I also started installing the Trail Tech Vapor. Got the unit mounted on the bar (had to pull everything off to slide the mount on), Temp sensor and the RPM lead hooked up. Today I ran to find an inline fuse for the power and started working on it but set everything down. I'm tired of looking at the thing and being in the garage for now. It's cold in there. Also I don't like working on electrical. Got the power and speed leads to mount yet.
 
Last edited:
If your adding more then 1 12v powered item,
lights, trial tech, perhaps USB charger, GPS, SAT TV,
what ever, consider adding a fuse box.. I really like the FZ1 and install a bunch of them each year.

http://www.fuzeblocks.com

Install done just once, and done cleanly, then you have 6 available circuits each one selectable as constant power or Key on. No hassling with multiple terminals on the battery. Centralized fuse location using a common fuse type.

attachment.jpg


attachment.jpg


attachment.jpg

then you have 6 available circuits each one selectable as constant power or Key on
And Ive done a few installs that powered the item both ways..So the rider could choose to have the item powered key off if they wanted



That's what I keep hearing, they drag a bit so stay on the brake. I'll keep that in mind when I start on it.

Well, I usually install everything. On this I was concerned that I can't use my left hand for clutch in case it isn't set right. I can't clutch the bike, kinda worried the maiden test ride would be a spectacle.

At this point installing it on my own would be easier. My schedule is killing me. it's tough to get the bike loaded and over there during their working hours. My weekends are too short.


Last night I installed a different rear tail (the other didn't have the LP light so technically not legal, I'd get pulled over 'round here). The wiring is a mess under there. I'll eventually need to redo all of it at some point. I also started installing the Trail Tech Vapor. Got the unit mounted on the bar (had to pull everything off to slide the mount on), Temp sensor and the RPM lead hooked up. Today I ran to find an inline fuse for the power and started working on it but set everything down. I'm tired of looking at the thing and being in the garage for now. It's cold in there. Also I don't like working on electrical. Got the power and speed leads to mount yet.
 

Attachments

  • VTR.jpg
    VTR.jpg
    26.4 KB · Views: 166
  • Tiger FZ1.jpg
    Tiger FZ1.jpg
    31 KB · Views: 164
  • Streety.jpg
    Streety.jpg
    31.7 KB · Views: 183
That fuse block looks nifty. I like it. It could clean up the under seat area really nice from the added-on street legal bits.

Thank you for posting that.
 
Back
Top