no power band

[J2PUISANT]

I get perfect idle. I get great acceleration at quarter throttle. Soon as powerband kicks in it boggs out. I checked jetting. Changed jetting. Checked reeds, cuz i changed for boyseen carbonfiber. Installed new crank and piston. Tors kit. Plug. I wanna get past this power band problem so i can move on and do ither things, but its been killin me for the past couple of weeks!!!

 

[Braaaptor]

Let's get a little more info... What size jets (main in particular; it sounds like the pilot is OK) are you currently running? I see you've got the TORS delete kit for the carburetor, so I'm assuming you're running the stock carb?

Here's a couple really odd things you may wanna check. One, be sure that your exhaust is not plugged up, either with carbon, a mouse nest, maybe a plug you forgot to remove from the last time you washed the quad?

Two, check your float level inside the carburetor, and set it to 20-21mm. If the float is too high, the engine won't recieve enough fuel when the main jet comes online, and it will fall flat on its face.

Three, remove and clean your fuel petcock. A clogged or restricted petcock will give you the same problem as a mis-adjusted float. Pull the fuel line off the carb, turn the gas on, and you should have a steady stream of fuel out of the petcock. A thin 'ribbon' of fuel, a trickle, or nothing indicates blockage or restriction.

Also, put an inline spark tester on the engine, run it, and watch for fire while you rev it. Your problem sounds fuel-related, but do the spark test to be sure that you're not losing fire when the engine dies out.

Does the engine rev OK with no load on it, and just die out when under a load? Or will it not rev without bogging, even with the trans in neutral and it just sitting there?

 

[J2PUISANT]

SORRY ABOUT THE LATE DELAY IN THE REPLY. Right now its got 240 main, 66.5mm piston, boyesen single stage carbon reeds, vitos paper filter, Stock header, pc pipe. Checked pipe its not clogged: 32.5 (stock) pilot jet Float could def be off, that would explain why it doesn't respond to jetting. Would mean not enough gas no matter what jet Need to know where to measure and whether it should be upside down or rightside up when I measure.
FYI: IT SEEMS TO REV FINE IN NEUTRAL BUT HAVEN'T REV TOO HIGH SEEING ITS A NEW/FRESH REBUILD MOTOR. NEED TO KNOW HOW TO ADJ THE FLOAT. DO I JUS BEND IT? ALSO I SAID IN THE POST THAT IT BOGS. CORRECTION. IT DOESNT SO MUCH BOG IT JUST FLATTENS OUT.

ALL YOUR HELP HAS BEEN APPRECIATED ALREADY. STAY WITH ME. THANKS IN ADVANCE!!!

 

[Braaaptor]

Ok, it's all good! I'll stick around and see if I can help you figure it out. A 240 main jet should be fine for your setup. To check and/or adjust the float level, take the carburetor off the quad. Remove the bowl and turn the carburetor upside-down. Take off the bowl gasket. You measure the float height at the float's top-most point. Measure from the top of the float to the gasket surface on the carburetor. Awk08 has a nice pic showing exactly what I'm talking about, and I'm sure he'd be glad to show you.

To adjust the float height, gently bend the tab on the float up or down to get it set right. I set one today that was an astounding 4mm off!! Wow. It runs great now that its set correctly. You are right; a float that is set wrong won't let sufficient fuel into the carburetor.

Before you take the carburetor off the quad, remove the fuel line from the inlet and turn the fuel petcock 'ON'. If you get a strong stream of fuel out of the petcock, all's well. If it just trickles or drips out, you've got a clog in either the fuel line or the petcock. Clean/replace the fuel line and petcock as needed.

One more thing to check: Have you done a leakdown test on this fresh engine yet? Usually, an air leak bad enough to cause your problem won't permit the engine to idle, but if you haven't tested it, do so. A tester is a whole lot cheaper than a new top end. You can get one cheap from Holeshotman on here. I have one and they work well. Don't assume your engine is airtight...test it and find out for sure.

 

[HawaiianBassHed]

do blasters have a parking brake switch?

 

[bagds101]

yes. the 03+ do. (i think its 03 but dont quote me on that) but i had that exact same problem. i did eberything. tore my engine down, replaced all my gaskets, new reeds, new and bigger jets, cleaned, cleaned, cleaned and then cleaned again. every nook and cranny in my carb. new throttle cable, cleaned air filter, replaced spark plug, and the only thing i could figure out is my quad wasnt getting enough air. i put my air filter on the back of my carb and my quad ran perfect. do you still have your airbox lid on?

 

[J2PUISANT]

Wow. I dont have it on. Are you saying that i should. Would that restrict air flow?

 

[bagds101]

if youre airbox lid is on then yes it would restrict airflow a little. if you have a uni filter or similar that will fit on the back of your carb, put it on and try it. it doesnt take much time and if it fixes it then it was well worth it. if not then you only wasted about 20 minutes.

 

[hudack]

if youre airbox lid is on then yes it would restrict airflow a little. if you have a uni filter or similar that will fit on the back of your carb, put it on and try it. it doesnt take much time and if it fixes it then it was well worth it. if not then you only wasted about 20 minutes.

he said he checked the jetting so if he did it right that rules out that solving it

 

[bagds101]

no it doesnt. i checked my jetting, changed my jetting from 260 main to 310 main and everything. i put my filter on the back of my carb with no box or anything with 300 main and problem solved. im just saying if it worked for me then maybe it will work for him. its worth the 20 minute work.

 

[hudack]

no it doesnt. i checked my jetting, changed my jetting from 260 main to 310 main and everything. i put my filter on the back of my carb with no box or anything with 300 main and problem solved. im just saying if it worked for me then maybe it will work for him. its worth the 20 minute work.

witch shows that your jetting was rich so the added air fixed the problem

 

[bagds101]

then why would it not change at all with my mods from 260 to 310? all the same. im not here to argue i was just saying to check that one thing that takes 20 minutes. and if thats the case then why do people get bigger carbs? to increase airflow right? if you have a stock airbox or a custom intake in my case and you switch to a filter on the back of your carb then that would allow maximum ammount of air to flow through your stock carb. correct? i was just saying. if it helps him then it was worth it. if not then he can go back to stock intake. no harm no foul

 

[hudack]

then why would it not change at all with my mods from 260 to 310? all the same. im not here to argue i was just saying to check that one thing that takes 20 minutes. and if thats the case then why do people get bigger carbs? to increase airflow right? if you have a stock airbox or a custom intake in my case and you switch to a filter on the back of your carb then that would allow maximum ammount of air to flow through your stock carb. correct? i was just saying. if it helps him then it was worth it. if not then he can go back to stock intake. no harm no foul

but when you increase that flow you gota add gas to even out the mixture all im saying is your jetting must of been rich not aurguing just saying why it fixed the problem a bogging slow powerband is a sign of it being rich

edit and also it could harm the pistion if you did that and it ran it to lean

 

[J2PUISANT]

Ok last time i posted i was going to do the following that was explained. I start the bike. This baby purrs sweet. Idles beuatifully. I mean it stayed running like this with no prob. So i put my helmet on (safety first). I kick down to first. Pop the clutch. And, and, and, bbbbddddddd... Nothing!!! I took off but no power band. I just wanna mention that in my findings i saw a few wires that were just hanging out. These wires went to the rear brake light and what i believe was the headlight. So i say this to say there are to last steps i am will to resort to because im at wits end. I feel it is one or two things wrong. It fuel or electrical. Like i said there are to parts i was willing to take. 1) swapping out a cdi box. I think it might of gotten burnt out by those wires maybe touching and make contact with each other. 2) swapping out the carb. Maybe if i can find a used one or just to put my mind at ease and get a new one. Im thinking that maybe one of the ports, holes, something in the acutual carb (thats not removeable) are clogged. Or something. Ive never been a parts swapper but this is bringing to places ive never been. What do you think? Thanks in advance!!!

 

[Muggzy]

Hey Justin,
Let's start at the beginning. To restate what you've got for mods that matter: your exhaust is essentially stock, the ProCircuit silencer (?) won't make a dif as far as air flow is concerned. The Boysen Reeds won't do much to effect your jetting if you had an after market pipe so it won't make much difference now (just a little better throttle response) you've got a Vito's filter that I assume is clean and correctly oiled (too much oil and it'll choke the engine) and no lid on your airbox, again not much impact either way since you've still got stock exhaust. So like Braaaptor said, 240 is probably correct for your main.

You just had this engine rebuilt at the close of the year. Have you ridden it since that rebuild? So is this a new problem or possibly an undetected problem that you're just finding out about?

If it's a new problem;
1) What was going on immediately before the problem started?
2) Have you made any changes since it last ran right?

If it's a problem related to the rebuild and initial set-up;
You've said it idles real nice with the 32.5 pilot so we can assume you've got the right jet and your air bleed screw is adjusted ok, but you said you get to 1/4 throttle and that is where it "bogs". This is the beginning of "mid-range' where the needle adjustment takes over and your needle may be way off. Do you know where your needle clip is set right now?

Btw, You should invest in a Clymer's manual - best $30 I ever spent.

 

[J2PUISANT]

Hey g,
hope all is well. Im glad you took a look at the post. Im gonna give you a call so you can get a better understanding ofwhat is going on. Ttyl buddy!!!

 

[Muggzy]

Hey Justin,

I'm out of town due to a severe family illness at the moment so don't call me in the next week. I have some time to kill at really odd hours though. So, I would like you to take the time to read the questions and answer them so others might learn from what we may discover in troubleshooting this problem together (if they search a similar problem in the future).

 

[BlasterDean]

I'm having the same problem .
Starts out that I don't do proper winterizeing. Gas stays in carb for 2 years. I go to start and gas runs out the overflow. So I rebuild carb. The main jest thats in the carb before I rebuild is unidentifiable. .
I have alien exhaust everything else is stock except the airlifilter. I read that i need a 2.60 or 2.7 with the alien exhaust. Zo i am currently running a 26. . It idles fine.
The air fuel mixture starts out at 1.5 turns from bottom out. The it sound best another half turn. . When I put it in gear it starts out fine. Anything above just starting out... no power. Its always been a great ride. So fast. .. now it sucks ass

 

[Slydog]

I'm having the same problem .
Starts out that I don't do proper winterizeing. Gas stays in carb for 2 years. I go to start and gas runs out the overflow. So I rebuild carb. The main jest thats in the carb before I rebuild is unidentifiable. .
I have alien exhaust everything else is stock except the airlifilter. I read that i need a 2.60 or 2.7 with the alien exhaust. Zo i am currently running a 26. . It idles fine.
The air fuel mixture starts out at 1.5 turns from bottom out. The it sound best another half turn. . When I put it in gear it starts out fine. Anything above just starting out... no power. Its always been a great ride. So fast. .. now it sucks ass

Got fresh fuel?try unplugging tors under hood.clean airfilter? Something make a home in your exhaust?

 

[Slydog]

Carb spotless?every hole and jet cleaned and blown thru.you can see light thru jets