GZ250 Sluggish, hesitates, slower than normal????

[Todubs]

Hello all! Long time lurker and sponge for all the info presented here! Thank you!
My wife has a 2006 GZ250 and recently found an issues we are trying to deal with.

The bike starts without any issues and runs fine at idle. But, when riding, the bike has no "power." Yes, I know it is a 250cc, but it seems to be MUCH slower than it was last season.

When accelerating, the bike "bogs" and is sluggish, but as the RPM slowly increases, suddenly the engine speeds up quickly and you take off with power. It's like a turbo lag kinda' thing.

Holding the engine at higher RPM doesn't seem to change it, still the sudden increase in power after a slow wait. The bike will go freeway speeds, but it takes a lot of time and is SLOW to get there. Also, the bike seems to backfire more when decelerating/engine braking (little pops from the exhaust).

The bike was parked in our carport over the winter with a full tank and Stabil fuel treatment. Ran fine before winter. This issue happens with full tank and low fuel level. Gas cap looks good. Spark plug was light brown and gapped correctly, even replaced with no change. Air filter and air box are clean and free. Vacuum lines are clear and I can't find any leaks in the carb boots. Petcock flows fine and the petcock filter was clear. No change with or without the air filter in place. No change when tank was flushed and fresh gas added. I drained the carb from the bowl and found no junk.

Any carbs issues with these bikes? I'm thinking I need to yank the carb and hose it out? This issue sound familiar with anyone? Bike needs the post-winter oil change, could that have an effect?

Any help would be great! I have no problem getting dirty and breaking out the tools, but I need an idea where to start!

Thank you for any help!

[patrick_777]

You probably need to clean the carb. Sounds like your jets are gummed up.

[blaine]

Originally Posted by patrick_777

You probably need to clean the carb. Sounds like your jets are gummed up.

STABIL is not a carb cleaner,only a fuel stabilizer.You might get away with putting some carb cleaner in the tank and going for a ride.

[alanmcorcoran]

There's lots of posts on here about carbs (many by me!) Bottom line, the GZ carb doesn't take well to non use. For many (most?) levels of gumminess, you can solve the problem by putting 150 miles (a tank of gas) with some carb cleaner. Occasionally, it can only be solved by cleaning the carb directly.

You can check your filter (easy to do and can't hurt) but is usually not the problem.

Make sure you shut the choke off after four or five minutes max, so you aren't running with it on. Try to get a good half hour at least of high speed riding in and ride it every day for a week.

[Easy Rider]

Originally Posted by Todubs

Any carbs issues with these bikes? I'm thinking I need to yank the carb and hose it out? This issue sound familiar with anyone? Bike needs the post-winter oil change, could that have an effect?

Yes, no, yes and no !! :biggrin:

Sounds like a lean condition; congrats for covering the air input stuff first. Did you actually check for vacume leaks with some spray or just visual inspection ??

Dirty carbs usually exhibit different symptoms than you describe BUT I would still try some carb cleaner in the gas first before tearing things apart.

Do I need to tell you what my favorite carb cleaner is ??? :roll:

[dannylightning]

Originally Posted by Easy Rider

Yes, no, yes and no !! :biggrin:

Sounds like a lean condition; congrats for covering the air input stuff first. Did you actually check for vacume leaks with some spray or just visual inspection ??

Dirty carbs usually exhibit different symptoms than you describe BUT I would still try some carb cleaner in the gas first before tearing things apart.

Do I need to tell you what my favorite carb cleaner is ??? :roll:

berryman B-12 chem tool, now you don't halve to say it lol.

if you put some kind of gas stabilizer in there over the winter i would make sure you get all of that out of the gas tank before you add the chem tool.

[Easy Rider]

Originally Posted by dannylightning

if you put some kind of gas stabilizer in there over the winter i would make sure you get all of that out of the gas tank before you add any kind the chem tool.

I was going to mention that an excess of Stabil can cause running problems but since he mentioned being on his SECOND tank of gas, I figured that wouldn't be a factor; maybe I figured wrong !!

[dannylightning]

Originally Posted by Easy Rider

I was going to mention that an excess of Stabil can cause running problems but since he mentioned being on his SECOND tank of gas, I figured that wouldn't be a factor; maybe I figured wrong !!

here is the thing about the second tank of gas, when he filled up those two times how much gas was left in the tank when he did fill up. if the tank was not close to being empty there is still going to be some left over stabil in there. if so would it be ok to add the b12 on top of that little bit of left over stabil. i don't know for sure but me personally would make sure it is all out of there before i add any thing else into the tank.

[Easy Rider]

Originally Posted by dannylightning

if so would it be ok to add the b12 on top of that little bit of left over stabil. i don't know for sure but me personally would make sure it is all out of there before i add any thing else into the tank.

Don't know for sure but I tend to agree with you and try not to mix things together.

[mrlmd1]

You said "Bike needs the post-winter oil change, could that have an effect?"
Next time you put it away, change the oil first before you store it. No reason to have dirty acidy oil sitting in the engine for months at a time, Store it with fresh oil.