DRZ125 Carb/ Fuel Issues

[Speed99 1,554]

Bike started and ran great the other day. The most recent change was to dial down the idle a little bit, but like I said. It ran fine. 

 

Went out to start it last night and it fired, revved, died. After that I couldn’t get it to fire. Wait a bit and it would fire a little and die again. 

 

Has fuel. Tried with petcock in On and Res position. 

 

The first thing that comes to mind is debris and/or petcock. Going to pull the line to see if gas flows. If not then pull the tank and petcock to see if it is blocked

 

Thoughts?

 

 

[Redbird 2,105]

Stuck float?

[Speed99 1,554]

Possible, but wouldn’t that cause the fuel to overflow?  Unless it’s stuck closed (or is it open). Lol

 

I guess if fuel flows then it’s in the carb. 

[redxxrdr 424]

My bikes with petcocks always had a mess sock over the inlet pipe to the carb.  Almost clogged?  Carb fills slowly, then bike runs . But wont continue after bowl runs dry.

You know the drill, pull the line from the petcock, and verify good flow.  If slow, remove the petcock, check for clogged screen or petcock.

If all is clean, carb clean time.

 

Oh yea, dad and i propped a ultralight for hours, only to find that we didnt have enough gas in the tank for the petcock set on full tank.

[Speed99 1,554]

I found a place local that has ethanol free gas. This is a good opportunity to pull the tank, empty it and start running good stuff

[Redbird 2,105]

1 hour ago, Speed99 said:

Possible, but wouldn’t that cause the fuel to overflow?  Unless it’s stuck closed (or is it open). Lol

 

I guess if fuel flows then it’s in the carb. 

 

It can stick open or closed, in this case I’d be guessing closed. 

[John01XX 1,248]

WaWa for the ethanol free for me

[Speed99 1,554]

1 minute ago, Redbird said:

 

It can stick open or closed, in this case I’d be guessing closed. 

My gut is saying it’s fuel starved. When left to sit, it gets enough gas to start and run for about 5-10 secs.  If was stuck closed would it behave like that?

[Redbird 2,105]

4 minutes ago, Speed99 said:

My gut is saying it’s fuel starved. When left to sit, it gets enough gas to start and run for about 5-10 secs.  If was stuck closed would it behave like that?

 

Yes, which is why I suggested it. Float sticks closed but maybe a little fuel gets by and fills the bowl while it’s sitting...bike starts, drains the bowl, dies. Just a possibility, I hate carbs and troubleshooting them. 

[Speed99 1,554]

Cool. I will check it all out tomorrow night. Not sure how to correct a stick bowl. Time to google

[superhawk996 1,669]

5-10 seconds is too short of a run to use up a full float bowl of gas, but there could be something really odd happening.  I think the easiest start would be to open the bowl drain and see if you get a continuous flow, if not then start digging for a flow issue.  If you do then check spark cold and after it dies.  I've had spark issues that 'feel' like a lack of fuel.  Last would be tight valves, but that seems like too short of a run for the stems to expand enough to kill it, unless they're at 0 lash when cold.  If none of that pans out I'll dig back into my brain for something else.

Edited March 5 by superhawk996

[Speed99 1,554]

Have great gas flow so it’s definitely not the petcock. Pulled the carb off and checked the floats. Everything seemed to move without restriction. Pulled the main jet and blew it out in case there was debris. Cleaned up everything and put it on. Started fine and ran, but now won’t hold idle. I hate carbs. Mostly because I am dumb when it comes to diagnosing them. 

[Speed99 1,554]

I just need this thing to run fine for one race day and then it goes up for sale to make room for my new CRF125.  The new bike won’t be here until later this month. 

[John01XX 1,248]

Looking forward to talking with you and Michael at RacerXX.

I have been looking at the Z125 and the Grom. Since I already own a Suzuki, Honda and Yamaha, I like the thought of adding a Kawasaki to the stable.

I want to talk with you guys about the advantages and differences between a CRF style verses street style (Grom) for fun/track occasional riding.

[superhawk996 1,669]

12 hours ago, Speed99 said:

Have great gas flow so it’s definitely not the petcock. Pulled the carb off and checked the floats. Everything seemed to move without restriction. Pulled the main jet and blew it out in case there was debris. Cleaned up everything and put it on. Started fine and ran, but now won’t hold idle. I hate carbs. Mostly because I am dumb when it comes to diagnosing them. 

Did you also check/clear the idle jet?  Your initial problem didn't seem carb related, unless that has an automatic choke.  But if it got better from only messing with the carb then maybe there's just something else in it that's screwed up.

[Speed99 1,554]

I fucking hate carbs. I hate it even more that a perfectly running bike 7 days ago is now not functioning as it should. Can’t wait to get rid of it and get the new bike that has FI. 

 

I tore the carb down and cleaned it all out. Seems like the problem is the float bowl and needle valve adjustment. I can’t find the sweet spot. It either won’t run or runs and won’t idle. I’ve exhausted my knowledge. Ordered a Chinese copy for $23 to see if it will get me thru the weekend. Then I can worry about a carb rebuild later. 

[superhawk996 1,669]

No idea if it would be worth the shipping, but if you wanna send it to me I'll go through it for you.

[brianmacza 435]

you checked for spark?

[Speed99 1,554]

1 hour ago, brianmacza said:

you checked for spark?

Yea

[Speed99 1,554]

On 3/6/2019 at 8:27 AM, John01XX said:

 

I want to talk with you guys about the advantages and differences between a CRF style verses street style (Grom) for fun/track occasional riding.

I can’t speak a lot to the differences between the Grom and Z125. I watched a few videos and they perform very similarly. I think the Grom has a much larger after market.  Michael can give you lots of info on this. 

 

For Street, I don’t believe there is a CRF 125 dual sport available. Dirt/trail only. You would have to stick with the Grom/Z125. 

 

For Mini Racing, the CRF125, Grom, and Z125 are legal for the Stock 100/125 and Stock 100/125 40+ classes. However, very limited mods are permitted. Stock exhaust. Stock motor. Stock suspension but you can upgrade internals and springs. Wheels and controls can be changed. 

[John01XX 1,248]

14 minutes ago, Speed99 said:

I can’t speak a lot to the differences between the Grom and Z125. I watched a few videos and they perform very similarly. I think the Grom has a much larger after market.  Michael can give you lots of info on this. 

 

For Street, I don’t believe there is a CRF 125 dual sport available. Dirt/trail only. You would have to stick with the Grom/Z125. 

 

For Mini Racing, the CRF125, Grom, and Z125 are legal for the Stock 100/125 and Stock 100/125 40+ classes. However, very limited mods are permitted. Stock exhaust. Stock motor. Stock suspension but you can upgrade internals and springs. Wheels and controls can be changed. 

 

Thanks,

I was more interested in the comparison between the dirt/trail (CRF) style verses the street (Z125) style on the track completing against each other in the Stock 100/125 40+ class. I saw where you were riding the dual sport at Homestead. Just wondering for the adult on a little bike difference, for the fun of it. Probably will not ever actually race but would be fun anyway. Also something to help the potential young rider to have an opportunity to experience the enjoyment of 2-wheels in a safe environment. Would love to get Collin, Brads son, on a bike.

[Speed99 1,554]

This thread has changed direction!  (In a good way. Fuck carbs!)

 

On the track:

Michael can definitely give you better advice on this. The bikes are pretty darn equal and, honestly, your riding skill the limiting factor since none of these bikes will allow you to correct cornering mistakes with straight line power. You have to be fast and consistent. Basically...if you are slow on a CRF, you’ll be slow on a Grom. Lol

 

 The Grom/z125 have 12” wheels if recall correctly. I am told they have a much different feel. Twitchier? Lower. Smaller.

 

  The CRF dirtbike style requires you to find the Big Wheel versions of the bike because the Big Wheel comes with a stock 16” rear and all you need to do is convert the 19” front to a 16”.  Throw a set of tires on it along with a few items needed to pass tech and you are ready to go. 

 

Just find one that doesn’t have Carb issues. I have ordered a brand new CRF125 Big Wheel. 2019. Fuel Injected. Yes!!!  The problem is that I have a race Sunday the the CRF won’t be delivered in time. They haven’t even hit the showroom floor yet. I could have gone with a 2018, but that is a carbed version. 

 

As far as Colin goes.  That’s easy. CRF50. Coopers is brand new (he really is a lucky kid....spoiled). I bought UFO plastics and put the original “Uncrashed” plastics in a box. Axle sliders. Peg sliders.  

[John01XX 1,248]

Will hopefully get to try both styles at RacerXX in 2 weeks!

 

My only other question... Does Coopers 50 have carbs?  🙂 

[Speed99 1,554]

20 minutes ago, John01XX said:

 

My only other question... Does Coopers 50 have carbs?  🙂 

Yes. No FI available on a 50 yet. 

[John01XX 1,248]

2 minutes ago, Speed99 said:

Yes. No FI available on a 50 yet. 

"Fuck carbs" !