04 yz250f what are these levers

[Jwrobin1]

Hey guys I just picked up a 04 yz250f my question is I have a silver thumb lever below my left grip similar to the one pictured and a red ball valve between handle bars that sticks up through back of front number plate pictured below the previous owner says the silver is hot start and the red valve was added later and just allows more air to engine and advised to always leave it open. Anyone else heard of this? Conventional thinking would be silver is decompression and ball valve is hot start but the bike is a 04 so there shouldn't be a decomp correct? But when pressure is applied to kickstart and silver lever is pressed the kickstart falls easily any help will be greatly appreciated

[k.g]

Yes, the silver one is a decomp lever. Never seen the other one. Can you show where that valve is leading to?

[Jwrobin1]

Top of carb but I thought 04 wouldn't have a decomp lever

[morphrider]

an 04 will not have a decompression lever. Take a close look at the cylinder head. On the throttle side there should be a plug there, if you see a cable going to it, looking like the posted picture, then it is not an 04. I dont have the cable hooked to it now, I put an 03 cam in my 01. It is where the spring is located. know what I mean?

 

[Jwrobin1]

Also why would he say leave the red one open at all times

[morphrider]

follow the cable on the red ball valve. Where does it go?

[Jwrobin1]

Red has clear rubber tubing and goes to top of carb

[Jwrobin1]

His words were its a Valve that let's air to the motor keep it what it was on

[k.g]

Pictures

[Jwrobin1]

Ok silver has to be a decompression and is top pic the tube from the red valve attaches to the carb in the second pic it's the darker hose on left by choke if this is a hot start why would he be saying to run it open

[ronbuell]

The one up by the number plate and connected by hose to carb is old style Hot Start.

The other one is Decomp lever.

[Jwrobin1]

So wouldn't running the bike with the hot start valve open cause it to run lean constantly

[Jwrobin1]

So I'm guessing keep it closed when not in use

Edited June 3, 2014 by Jwrobin1

[morphrider]

Yes, keep it closed. What you have is NOT an 04 model. It is either an 01 or 02. Here is a pic of my carb, an 01.

Edited June 3, 2014 by morphrider

[ronbuell]

Normally running it is closed... no air entering the engine.

When you stop, and its hot, opening it will aid in starting and that's what its for.

Once started, you close the Hot Start.

 

The Hot Starts incorporated in the carb body use filtered air, which is infinately better that open air.

They learned that once the hose cracks or worse, falls off, dirt gets in and it doesn't run properly.

[Jwrobin1]

Thanks all yea according to the VIN it's a 01 which makes sense since it has decomp lever. The seller had it listed as a 04 which is why I was wondering what the heck I was looking at!