bike wont start cant figure out why?

[justin4260]

this bike is a 2002 buell blast it has about 1800 miles on it and it wont start cant figure out why. it has a clean carburetor intake boot looks brand new spark from plug boot haven't checked actual plug yet. charged battery and new oil. all good fuses. it was started and put on my trailer but would start when I got home. still wont start got it in January. any thing you think I should check? it does turn over just wont fire up.

[snrusnak]

These bikes are prone to plugs fouling especially on short runs when cold. Could have fouled the plug. Same thing happened to me as you're describing(started up fine when buying it then get home and won't fire). I replaced the plugs and it ran fine. That was like 3 years ago. Mine's an xb but basically same thing.

[justin4260]

I checked plug and yes I got spark what else should I check?

[jetlee]

These bikes are prone to plugs fouling especially on short runs when cold.Â* Could have fouled the plug.Â* Same thing happened to me as you're describing(started up fine when buying it then get home and won't fire).Â* I replaced the plugs and it ran fine.Â* That was like 3 years ago.Â* Mine's an xb but basically same thing.

1st: They're not "basically the same thing", different head and piston design which means a different wavefront and burn pattern.
2nd: Blasts are not prone to fouling. You can run these engines so rich they barely run, and the plugs won't foul for weeks.

Do the cheap fixes first:
Turn fuel to Reserve (thumb thingy on the front side, arrow pointing rearward)
Replace fuel
Replace air filter
Replace plug

You don't know how old any of them are. You plug may be sparking, but if it's old and worn then it may be too cold of a spark (check gap).

[justin4260]

i checked gap and the air filter it realy clean the plug was all black though and tthe plug was at 45mm i will replace fuel though. and probobly the plug to i dont know bout the air filter

[jetlee]

45mm? No.

Buy an NGK DCPR9E and gap it to .040"

[justin4260]

I just replaced the carb boot and Intake gasket so I could make sure I was getting the right compression .q I checked the jets and they are clean. I tried starting it on reserve and nothing. After I changed those parts it would sputter and then backfire through carb. Shoots smoke. I drained the gas and it was all yellow and cloudy. Also gas in carb was yellow and thick. But the carb is clean. Charged the battery. Still nothing. I'm gonna replace the gas. What kind of gas should I put in it?

[Negative]

87 octane or higher on the blasts according to a manual from a 2006 blast ... I run supreme in my xb because that's what the manual calls for ... and I run regular in my r6 because ..... well, that's what the manual calls for ... No problems to date ...

[justin4260]

Ok mines a 02 but it should be the same thing. Would the bad gas cause the backfire and no start? The bike only has 1800 miles on it. Spark plug is good, I changed the carb boot and checked the jets, they are clean. Just dirty gas. I tried cuffing my hand over the carb intake but that didn't work I just got smoke shot in my hand. lol

[Negative]

Bad gas will cause anything to spit and sputter ... and from the sound of it you've got the basics of the engine covered ... Remember a motor needs three basic things to work (provided it's mechanically sound of course) ... Fuel, Spark, and Air ... without any one of those three it will not run under normal circumstances ... You've already checked the spark (good) ... It's got to be getting air (obviously) ... so that just leaves fuel ... and I would keep my hand clear of an intake and let the choke do it's job ...... had a tiller backfire and catch on fire at the intake one time when I was using my finger as a choke over the intake ... hahaha ... life's lessons learned the hard way ...

[justin4260]

Ok thanks for the reply. I'm gonna put new gas in it tonight and see if that works. Also I had gaped the plug at 45mm and it's supposed to be from 38 to 43 according to my research. So I put it at about 39 or 40 and clean it. It had gas on it and it was black.

[Negative]

Keep a few spare spark plugs handy until you get it running right ... I always keep a few select parts handy for each of my bikes ... Oil, oil filters, spark plugs, clutch cables, master links (for the ones with chains), and headlights ... [up]

Always a good idea to check every spark plug before installation, I know I do as it only takes about 3 seconds to do ... I have a spark plug gapper (one of the little disk shaped ones) in my toolbox ... It's not as accurate as a micrometer or feeler gauge by any means, but it's close enough for my use ...

[jetlee]

Your gas should be clear as possible for the Blast. Run as high octane as you can find at the pumps. The Blast piston/head combo does not run very well with low octane fuel.

[Negative]

After reading that, I defer to Jetlee's advice on this one regarding the gas octane ... He actually HAS a blast and can give first-hand info vs my info which usually comes from information seaches and recalling older thread discussions ... In other words, my advice should be taken second to his as I have a few 4 cylinder bikes and an XB ... [up]

[justin4260]

Ok. I have a gap checker (the disc kind) on my keys, everywhere I look the spark plug is like 10 bucks. That's expensive for a regular spark plug. And I think the Kroger station has 91 or 93 octane.

[Negative]

Sounds Like An Iridium Plug ...

[jetlee]

$10 expensive? My Blast plug was $35 (Denso Iridium Racing) and the only plugs available for my car are $14/ea and I require 4 every oil change.

$10 is not expensive, dude.

Negative, thanks for the compliments. I'm merely a guy that's been there and done that. ;)

[Negative]

NGK offers standard copper tipped plugs for my xb for about $4 a plug... The next step up plugs are about $9 a piece... The premium plugs are about $17 a piece at my local advance auto parts warehouse... (these prices are with a military discount)...

Every post I see dealing with ANYthing blast related you are on it like white on rice jetlee.. And your answers are very detailed and informed... My compliments are the truth man.... I'm only offering general suggestions and advice on a bike that's merely similar in certain ways to mine... You sound like you've built one of these bikes from scratch!! ... Lol

[justin4260]

well I don't want a racing plug. Harleys site has it for $5 with free shipping. anyway I don't need a plug I need new gas. turns out I didn't have time to get the gas last night so ill have to try today.

[jetlee]

You sound like you've built one of these bikes from scratch!! ... Lol
Close, lol.


well I don't want a racing plug.
Yes you do, you just don't know you want it, yet. If you ever get one in the future, you will be kicking yourself in the ass for not doing it now.


I've ran Rat Blastard soo rich that you couldn't come off idle without stuttering from being flooded. Rode it a few days like that, just didn't feel like messing with the jets at the time. Pulled the plug later for other reasons, looked nice an tan like a normal plug.

The Racing Iridium is very foul-resistant like you can't imagine. Just be sure to never gap it.

[justin4260]

if I was going to keep the bike I would totally get one, but im just fixing it to sell so I can buy a different bike.

[justin4260]

ok I got gas last night, I put it in and... no good. it turns over, fires for a split second, keeps turning and just repeat the process for few seconds then backfires and shoots smoke. maybe the timing is off. but then I checked the oil and it was over filled. not sure how because I had filled it a few weeks ago right in between the fill lines. so I drained it back to were its supposed to be and know it doesn't shoot smoke or fire for a second. im not sure what is causing this.

[justin4260]

so im getting air, and getting spark, so now I need to focus on fuel. its not floaded and I cant smell fuel, so I know its not getting enough fuel. (if my logic is correct). so what do I adjust, do I shim the needle or adjust my auto enricher. or both. if needle were do I get the shims?

jetlee- I have watched your 2 videos on youtube about tuning your cv40 carb, and adjusting your auto enricher. so know I now how to do it. awesome videos man! just I don't know which one to adjust, the needle or the enricher?

[justin4260]

I should also mention that because the manual says run 87 that's what I got. I think its still trying to burn off the bad gas that's in the engine.

[jetlee]

I actually have four videos (http://buellridersonline.com/forum/showthread.php?t=8291) about the carburetor...watch them all. (thanks for the compliments)

Make sure you have ALL the parts properly installed in your carb (jets, emulsion tube, collar)

1.If you haven't adjusted your auto-enricher, DON'T. If you have, set it to half-open when cold (ambient temp) like my video shows.
2. Put your needle to stock, it really doesn't matter for start/idle.
3. Put your jets to 45/170 (unless you have aftermarket exhaust, then 45/175).
4. Turn your idle mix screw out 2-1/2 full turns (900*) from soft-bottom (just barely bottomed out).
5. Check your ignition timing following the manuals instructions or this (http://buellridersonline.com/forum/showthread.php?t=3739) video.
6. Check compression, you need 130psi at least.
7. Check for spark at the plug (just to be sure, since you have it out for the compression gauge anyways)

If that doesn't work...where do you live?

[justin4260]

i haven't adjusted my auto enricher. needle is at stock my jets are stock also, I don't have a compression guage so ill have to buy one and I have spark at plug. it shouldn't be some big issue since the bike is almost brand new and it started before I brought it to my house on a trailer. im going to pull the carb off and adjust the idle mixture screw how you said to do it.
also, I live in Katy, Texas.

[justin4260]

i just took the carb off and adjusted the air fuel mixture screw to 2 -1/2 turns from soft bottom. and when i took the carb off i realized i didn't plug back in the auto enricher and throttle positioning plug! i wonder if that was why it didn't start after i changed the fuel. it would fire and die and fire and die ever other second so i guess because the enricher and throttle was off that might have caused it. im gonna put the carb back on, plug that in and see it it will fire.

[justin4260]

ok so i just put the carb back on and pluged the thing in, put all the stuff back on and....still no good. now im getting frustrated. i have tried almost everything you can do. i took the jets out and sprayed w-d40 through them them wiped em dry. i also wiped the needle off cuz it has some gunk on it. then i poured all the old gas out of the carb, and wiped the whole thing clean. i also did the air fuel mixture like you said. i guess il post a video later today of what its doing. i also took the timing cover off and the led light is not on. ( with the key in the on position). i don't have a bit big enough to take that bolt out of the whole. does it have to come out to move the timing box so i can get the light on?

[jetlee]

I use a big flat-head to take the plug out. You have to get the plug out to check the timing.

Take the carb back apart and clean it with "carb/choke cleaner", NOT WD-40.

Have you bypassed your kickstand safety switch and your BAS? Pull the plug and jumper the wires together.

[justin4260]

well I didnt clean the carb with wd-40 I just wiped it with a towel. I only sprayed the jets after I took them out with it.
what does bypassing the kickstand do? and I don't have carb cleaner. its pretty clean, no gunk anymore. what is BAS? is that the clutch safety switch?

[justin4260]

every one is saying you have to drill out the timing cover, but I just pop mine off with a small flat head. its plastic and bendy so it just bent and popped off. and in your video you didn't lift the rear wheel or put it in fifth gear or anything. is that on a different bike you do that? not on blast?

[justin4260]

so I got my timing cover off, put my line at tdc, and the lights not on. the ignition module wont even move. I checked my battery and it was 12.3 so I put it on the charger. would a low battery cause the light not to come on? why wont the igniton module move?

[justin4260]

I figured out how to get it to move, you just loosen the screws! but no matter how little or much I turn it the light doesn't come on at all.

[jetlee]

every one is saying you have to drill out the timing cover, but I just pop mine off with a small flat head. its plastic and bendy so it just bent and popped off. and in your video you didn't lift the rear wheel or put it in fifth gear or anything. is that on a different bike you do that? not on blast?
You don't have to drill it, just get it out with whatever method.

I don't lift the rear wheel in my video because I already had it in gear and just push the bike back and forth to get the line to line up.

Turn the engine over 360 degrees, you're likely at TDC on the exhaust stroke instead of TDC on the compression stroke.

[justin4260]

is the compression stroke with the line, and the exhaust with the dots? im using the line. I read in a post that there are 2 dots, then there is a line. maybe that's on a different bike because im not seeing 2 dots.

[justin4260]

ok so I rotated the wheel 360 and still nothing. then I rotated it 180 and nothing. is my ignition module bad?

[justin4260]

just watched a youtube video of howe to bypass the side stand switch. easy!

[jetlee]

ok so I rotated the wheel 360 and still nothing. then I rotated it 180 and nothing. is my ignition module bad?
Not the wheel, rotate the crankshaft 360* so the line re-appears in the middle of the window.

[justin4260]

wouldn't rotating the wheel do that? if not how do I rotate the crankshaft?

[Negative]

He's trying to say that one full rotation of the back wheel is several rotations of the crankshaft... You only wanted to rotate the crankshaft a full turn, not the back wheel...

Think about it like this... Starting from the intake stroke of your motor, the crankshaft rotates 180 degrees to make it to the compression stroke, then the power stroke pushes it another 180 degrees to the exhaust stroke, then it's another 180 degrees back to the beginning of the intake stroke again...

Basically that's two 360 degree rotations of your crankshaft for four cycles in the engine.... Only ONE of these 360 degree turns needs to be timed for the spark plug to fire.... That would be TDC of the compression stroke... Jetlee was saying you were probably trying to time the motor when it was at TDC for the exhaust stroke.... That was the next 360 degree turn of the crankshaft... He was suggesting that you turn the crankshaft over again to get it on the correct cycle of the engine...

Make sense??... =)

[wormburner]

This may be to obvious but my son`s 01 blast quit on him on the road. After checking spark,fuses,fuel level,gas cap-vent I was about to rip the carb off. when I grabbed the air box I thought it did`nt feel right. Well guess what?
The carb had popped out of Das boot. Rebooted so to speak and lo and behold, the bike fired right up.
Hope this helps. This is what happens when you put a big ol carb on a big ol single, sometimes.