Carb issues

[toddmac]

Hey gang,
I got a carb tuning question. We just picked up the 98 Warrior I bought for us and I noticed it has a very bad bog or hesitation when ya crack the throttle. If ya open it slow it runs fine, it runs strong thru the gears but when ya give it a good crack she bogs heavily.
I have printed off some jetting info from the tutorial issue but this particular issue is kinda what I see on a normal car carb with an accelerator pump issue.
I plan to check all the settings tomorrow but I'm thinkin this issue might be more internal than external settings.
Any ideas on what to look for would be appreciated!
Thanks, Todd

 

[yamarider]

Sounds like you already have the right idea. The accelerator pumps are notoriously problematic on the stock carbs. There's a number of things that can go wrong, all which are fairly simple to deal with most of the time.

To confirm that the accel pump isn't working, take the carb off, or at least the boot on the airbox side. The nozzle for the accel pump is a small brass needle that sticks about 1 cm into the bore of the carb, on the airbox side. If it's working, when you hit the throttle quick you can see the gas shoot down the throat of the carb (or out the airbox side if the needle was installed backwards from the factory, as mine was).

No fuel squirting out will confirm that it's not working.

The most common cause of this is that the return spring for the accel pump plunger is broken or completely missing. The spring belongs between the accel pump and float bowl, so quite often when the bowl gets taken off to clean or rejet, the spring falls out and it doesn't get noticed, then the poor response gets blamed on bad jetting, which gets everyone chasing their own tails...

Anyways, if the spring is missing or broken, the simple solution is to remove the spring from a cheap mechanical pen to replace it. They are usually the perfect size, and stronger than the original one so the pump is less likely to get stuck and not return.

Take a look at it and let us know what you find out. If everything I mentioned looks ok, there's still more to look for.

 

[toddmac]

Thanks for the info! I will get that checked out tomorrow maybe and see what I can tell!

 

[madcow]

Mine was giving me nonstop issues, I replaced the spring, stretched it a bit, replaced the o-ring and it still got stuck. I don't know what's wrong but I just gave up on that carb.

 

[darebee]

I have not had problems with my accel pumps, but I can see how they can easily stick if a bit dirty.
It is possible dirt in the system or bad jetting, but I found with both of my Warriors that a little fine tuning of the low speed adjuster screw completely removed the stumble.
If you have a pipe/filter the low speed circuit likely is lean on 2 turns out.
I am about 2.75