Need opinions on whether I should pull carb on 2005 Scrambler

[p5200]

Hello folks, my machine wound up with I think water in the tank etc. It runs but speeds up and slows back down randomly. When not running I don't see gas dripping  from the drain nipple on bottom of float bowl and drain screw is closed tight. With normal idle speed I see no leaking. When the idle speed increases quite a bit on it's own, gas appears to start slowly dripping from float bowl drain nipple? I'm wondering if the carb is flooding and the gas is actually coming from higher up and just appears, to be coming out of nipple but, is actually running down the sides of the nipple? I put a kit in the factory Mikuni carb last year after sitting for a while and I think the gas in the jug I used had drawn moisture. I plan to pull the carb tomorrow and clean everything out. I was just curious if anyone else thinks it's probably something in the carb and is, acutally a flooding problem? Thanks Folks! 🙂

[Mech]

I think it will be flooding. Some carbs that drain screw drains the water from the bottom of the bowl and out that nipple, but the nipple is actually attached to a brass tube in the bowl that goes up high and drains fuel if it gets too high.. Or to explain it differently, the nipple goes to a tall overflow tube, and the drain screw just lets fuel bypass the top of the overflow and go straight into the tube from the bottom.  Hope that makes sense.

And yeah, the fluctuating speed and all could definitely be caused by changing float level..

Once you have it off then you can give it a good clean and know it's good. I'd do it. And.. I take heaps of carbs apart, clean them and put them together again without changing a single part, and they are all good. The only problem is if the rubber gasket between the bowl and body is old and shrunk or swollen and doesn't want to stay in it's groove when it's time to put it back together.. Then I fit it all carefully all the way around holding it down with a 25 thou feeler gauge to hold it flat and in the groove till I've pressed the bowl into place, then I slip the feeler out. Everything else goes back together easy. Take every brass bit out and clean them. Clean the tiny holes in the sides of the emulsion tube the main jet screws into and that the slide needle drops down into. Take the float needle seat out and check the O ring or gasket that seals between it and the body. People seem to assume it's only the seat and needle that play up and leave the seat in.. Bad plan.

[p5200]

That some good info, I'll take it off in the morning and get started on it. It hasn't been that long since the kit was put in. Maybe everything will come apart pretty easily. I'll keep my fingers crossed LOL! Thanks Again Mech! 👍

[Mech]

If it has a diaphragm on the side and it's stuck in place you grind the end of a feeler to a sharp edge right around the end of it and use it to gently prise and work the diaphragm off.

[Gwbarm]

It seems if it was overflowing at the float bowl it should leak more at idle than higher speeds, as you go faster the level in the float bowl goes down and should not be coming over the side.

[p5200]

It may not be leaking bad when I'm actually riding. I just noticed the smell of gas when idle increased when sitting still. Hopefully I get it straightened out. This happened right after I got right front wheel drive going lol!

[Gwbarm]

That almost sounds like the float level is too high or the needle is not completely shutting off the fuel flow. I would check all those things when you take it apart. It shouldnt be leaking at the bowl gasket so pull the gasket out carefully clean the surfaces good and reseat it. I have had trouble with the carb drain leaking even after i replaced the o ring they would still leak a bit, i might have to reseat it several times to stop the leak, so check that seal out good also. Just some thoughts.

[p5200]

Well I got the carb off all cleaned out and put back on. I ordered a new air filter. I think the one that was in the air box must have came on the machine it's horrible looking. The air box is filthy, so I've got to clean it all up before putting back in.  Here's what they look like. 😨

[Gwbarm]

That definately needed some attention you should run better with a new filter on, did you find any other obvious problems with the carb.

[Mech]

That filter looks like mine and just fine to me..

but I'd oil those pliers !! 

[p5200]

I didn't really see anything that stuck out but there was some tiny debris. I'm hoping cleaning everything out will cure my problems. I'm going to put just enough back together to start and run. If it's still flooding, the only other thing to try is checking the float level. I got a new float needle when I put carb kit in.

2 minutes ago, Mech said:

That filter looks like mine and just fine to me..

but I'd oil those pliers !! 

I already ordered a cheap filter I guess I can put it back for a spare

[p5200]

I've heard some people soak the filter covers in oil then squeeze them out and put back over the filter. Does that sound right?

[Gwbarm]

I think thats pretty standard procedure for foam filters with metal support, there is a special spray oil for them. 

[Mech]

Oil traps the dust and stops it working it's way through the filter or cover.. Engine oil is fine. It does need squeezing out because too much oil can make them run rich. If you give it a good oil and work it through with your hands, then put the cover in a rag to soak up the excess when you squeeze it in your hands it will come out about right. Just squeeze it, don't wring.

And I was just kidding about the old one looking fine.. Even I would change that one.

[p5200]

I wondered if you were serious! 😄

[Mech]

Ya know.. cobbler's shoes..

I am pretty slack about the maintenance..  Actually..  I'm worse than slack !

[p5200]

I need to change the oil in my it's well over due.

[Gwbarm]

I never oil my filters no particular reason, i guess so if i see them oily im having some engine blow by. , i do oil 2 stroke filters, they get oily anyway.

I like the pliers it took years to get that amount of patina, priceless.

What oil are you going to use, i think they are all good, just curious as to what other members are using.

[Mech]

I use engine oil but if it was a very porous sort of foam filter(or an old sock) I'd use chain bar oil..  nice and sticky.

[p5200]

I'll probably use a little of the engine oil for the Scrambler. 🙂

[p5200]

I got it going today started right up. There was a little faint puffing out exaust for a while. I added another 1.5 gallon 93 octane instead of the 87 octane. So far it holds its idle with no surging or gas leaks. There's a sort of petcock mounted to the frame. Funny thing about it is, there's nothing on the back side of it. 😂 All this time I thought I was shutting off the fuel when not riding it lol! Somehow the gear shift got moved into reverse. When started it wound up pushing me  backwards about 20 feet before I could shut it off. Someone must have messed with it while I was in the house. 🤔I sure thank you guys for all of your help! 🙂

[Mech]

Ha.. Gremlins.

Good to hear it's coming right. I'd try and get the fuel tap. Float needles that work just fine all day long can still be leaking a tiny bit, not enough to upset the running or cause any problems in a day, but they can slowly fill the sump when the bike's left for a few days.

It's probably not meant to be able to start in gear either.. It's a safety feature.

Stupid safety !

[Gwbarm]

Good! That worked probably a combination of carb and air filter.

[Mech]

Yeah cv carbs are quite fussy about their air-filters. No air-box, or too much or too little oil on the foam filters can make them behave real bad.