Blaster Idle Problems

[DeJay126]

I recently bought a 2001 Blaster, I've been riding it for a few days now and have noticed that it will not idle (or idles high) unless it is half choked. This is my first quad and I have no idea what's going on. When I choke it, it won't run right (bogs down before normal power is restored) so I've been reaching down and pulling the choke half way when I want to sit and idle. Then push it back in when I want to start riding again. I also noticed that when I'm riding, and am not pressing the gas (coasting) it runs weird. I can't really explain it, I guess you could say it jumps a little. Like the engine revs a little and slows down and repeats, until I choke it half way. So when I'm going down a hill, I either have to choke it, or keep it in a higher gear and press the gas a little so that it runs normal. I'm not real sure what this would be, but if anybody has any suggestions I'd really appreciate it.

 

[DirtDiggler]

You need to perform some maintenance before you continue riding .
The carb needs to be cleaned , you need to inspect for air leaks and you need to tell us what's been done to the quad to see if you have any issues .

 

[DeJay126]

The only things that have been done (as far as I know) is that a FMF Powercore 2 has been installed. And boysen racing reeds are installed. I'm not sure if it's been jetted since the FMF has been installed, could that cause the problem? I forgot to add that I was riding a few days ago, got stuck in mud, and the throttle somehow got stuck open and I had to hit the kill swtich.

 

[Blaaster]

If you are having to give it more fuel by choking then there must be too much air in the mix.
First thing to do before you ride it again is to clean out the carby, and then do a leak down test

 

[DeJay126]

Would this be happening if the person who had it before me didn't jet the carb when they put the pipe on it?

 

[Blaaster]

Have you upgraded the pipe or just the muffler. If it is only the muffler no jet changes should be needed.

What main jet is in there?

 

[DeJay126]

I didn't upgrade it, but a new pipe and muffler were added. I'm not sure if the jets were changed. Like I said I just got it Wednesday, and I'm new to having a quad. I have to ride it to get home tomorrow (about half an hour ride) and then later on tomorrow night I'll take off the carb and clean it. If that doesn't work, what would you suggest?

 

[Blaaster]

You need to check that main jet before you ride it even for a minute.

It should be around #270 - #280 with a FMF pipe.

If it has not been jetted for that pipe, on your head be it.

Take a tip, do not attempt to ride it for 30 minutes without at least checking the jetting, it can be a costly exercise not only in repairs, but in shoe leather too.

 

[DeJay126]

If it hasn't been jetted, then there's probably serious problems with it, because the kid I bought if off of never touched anything. He rode it for two years, and never had any problems (so he says). Anyway, I'll check it tomorrow. Do I only have to change the main jet? And where can I pick one up if that's the problem.

 

[Larry's Shee]

Does the pipe look like this one YAMAHA BLASTER STOCK PIPE | eBay See how it's fat, then thiner just before mount then fatter? This is a stock pipe

 

[DeJay126]

No, it's an FMF pipe, has the emblem engraved on the fat part.

 

[DeJay126]

I'm going to clean the carb tomorrow, and check my main jet. Is this the only thing you're thinking could be the problem, or could it be something more serious?

 

[Blaaster]

You are in a little predicament not being at your home and having to ride it.

I cannot guarentee it but a #280 main jet should get you home, if you take it easy.

The proceedure to perfect jetting is to fit a jet and then do a plug chop to see where your jetting is at, then correct and do another plug chop to confirm.

You should be able to get a few jets from any motorcycle or ATV shop. Get #260 through #300.

There is also a high possibility that there is an air leak causing a lean mixture, but only a leak down test can tell you that.

You colud try spraying some starting fluid around the reed cage and intake boot, if it idles better then you may have an air leak, and then you may be able to seal it.

 

[DeJay126]

So, after that the idling/coasting problem should be fixed. Once it it jetted properly?

 

[Blaaster]

So, after that the idling/coasting problem should be fixed. Once it it jetted properly?

Idling problems are usually caused by dirt in the carb, poorly seating reeds, blocked idle jet, or air leaks.

You should be able to get it home with an idle problem, but dont bank on getting it home with a jetting or air leak problem.

 

[DeJay126]

Okay, then it must not be a jetting problem, because the person before me rode it for 2 years with these jets and the new exhaust system installed. It was all in place before he got it. I'll ride home in the morning, and tomorrow night I'll take the carb apart, clean it, and check the jets. Here's another bit of information for you. When I rev the engine, it seems to take a really long time to come back down to idle speed. Maybe 5 seconds or more sometimes. I'll check the jets tomorrow night as well. What do you think about it taking a while to come back down to idle speed?

 

[Awk08]

adding to the above excellent info..............

idleing has to do with the pilot jet/circut, and it sounds like you may have some blockage that a cleaning should remedy, the pilot jet has a very small hole that can clog easily, it is located down in an orifice right beside the 6mm hex main jet < you'll see sticking up when you remove the bowl, the pilot jet takes a very small straight blade screwdriver to remove
spray carb cleaner in all jets, orifices and passages, then blow put out with a compressor, reassemble, be sure the brass washer goes back in under the main jet.

your air screw setting also effects idle, it is located right behind the fuel inlet on the outside of the carb body, brass screw, it should be 1.5 turns out to start, but can be fine tuned from 1/2 - 2 turns out for highest idle setting, then adjust idle screw accessed under the seat/fuel tank for desired idle

while you're in there.......
the needle should have the clip on the middle setting and float setting should be 20-21.5mm, measured like this
(bend center tab to adjust)...........

 

[DeJay126]

I appreciate all of the help guys. I gave you both some rep! I'm going to tear the carb down tomorrow afternoon/night, and clean it out. Should I remove ALL jets and clean them as well?

 

[Awk08]

I appreciate all of the help guys. I gave you both some rep! I'm going to tear the carb down tomorrow afternoon/night, and clean it out. Should I remove ALL jets and clean them as well?

remove everything, all jets, floats, float valve, choke assembly ect.

here.............
http://www.blasterforum.com/general-support-17/how-clean-your-carb-pics-209/

and...........

http://www.blasterforum.com/do-yourself-20/heres-how-clean-your-carburetor-43238/

also...if pre-mixing the fuel/oil, (oil injection delete? )
is the oil injection inlet blocked off ???
opposite side from choke, up high, near the back, (brass nipple) and/or black hose connected/cut off
it must be blocked off with a screw/rtv or small vaccum cap or it's gonna suck air and do exactly your symptoms, and eventually fry your chit !

 

[DeJay126]

It has the injector system, I've read a lot about people removing them. I did notice a brownish clear tube up by the top of the engine above the choke that has been clipped, and isn't connected to anything. It's only about 2 1/2 inches long, running vertical.