Trouble starting when cold

[Khumarahn]

Hi guys. Sorry for one more topic on starting in cold weather, but I couldn't figure out the answer in my situation.

I have 2003 gz 250, and I have to follow quite a procedure to start it at around 40°F or colder.

First of all, it works fine when warm. When cold, I have to
1) use choke
2) turn fuel valve to "PRI"
3) use 1st gear (doesn't start in neutral)
then wait half a minute, or try to rotate the engine by pushing bike forward or backward; and then it starts fine.

I am total noob in motorcycle repairs, but I believe I have straight hands. From what I understood, battery may be the problem. I tested it in Autozone, and it was bad, and I replaced it with a new one. But the problem persists.

What should I try next? Clean the carburetor? (what cleaner to use?)

There are also traces of oil on the grill, as if some gasket on top of the engine is leaking... I wonder if this is related.

[Rookie Rider]

Did you charge the new battery over night, or just put it on the bike right after buying it ? Please say you charged it fully before putting it on the bike.

[jonathan180iq]

We all are fairly fond of Seafoam or Berryman's B-12 Chemtool for maintaining a clean carburetor. I also am partial to Marvel Mystery Oil, but I'm kind of a weirdo. (Might want to buy a can of the pressurized stuff too, just to have at your disposal.

The remnants of a black or brown substance on the petcock side of the engine is very common with these bikes. Clean it off and monitor it to see if it returns or how quickly it grows. It may very well be nothing more than the left over shipping oil that was put in the bike when it was new. Seems like every single GZ owner has seen that smudge.

How much choke are you using? In weather that cold, you're going to need full choke. That's normal.
You shouldn't have to use PRI to start the bike, ever, unless it has been broken down and you need to refill the float bowl.
Is it possible that you just THINK you need PRI and you really don't? If you actually need it, then you have a vacuum issue, where the engine pumping isn't sucking the fuel through the system... OR you have a dirty carb, as you've already suggested.

Since it's the winter anyway, and this season is hard on a bike, I would take the time to check the condition of your vac lines, get yourself some carb cleaner and spend some quality time with her. These things are so simple to work on, and there isn't a whole lot that goes wrong with them. The few things that are common, we all know how to walk you through. You'll get it sorted.

[Water Warrior 2]

Needing to have the tranny in gear is weird. You do realize you must have the clutch pulled in even when in neutral while attempting to start the bike. If the bike is new to you there may be a learning curve involved more than anything. Also, just a heads-up. Before attempting to start the bike you may want to pull in the clutch 2 or 3 times to loosen up the clutch plates from each other. This applies to cooler temps from my experience.

[alantf]

Originally Posted by jonathan180iq

The remnants of a black or brown substance on the petcock side of the engine is very common with these bikes. Clean it off and monitor it to see if it returns or how quickly it grows. It may very well be nothing more than the left over shipping oil that was put in the bike when it was new. Seems like every single GZ owner has seen that smudge.


You shouldn't have to use PRI to start the bike, ever, unless it has been broken down and you need to refill the float bowl.

With regard to these two points..........

My bike's got around 23,000 km on the clock. Recently the stain kept coming back. Took it to the shop, and they found that the cylinder head bolts needed tightening up. Problem solved.

If I don't ride for a few days, the bowl seems to empty, so I use prime, because if I don't, I'm using the battery for too long a time, to suck fuel in & get it started. When I'm riding every day, no problem. I've had the bike for nearly six years, so I know all its funny little quirks.

[raul10141964]

the valve cover use RTV silicon lake gasket an always leak
to start use full choke and no gas