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Buell Blast Forum - Buell Blast Motorcycles - Buell Blast Discussion



Welcome to the Buell Blast Forum aka the "THUMPer Forum".

For Buell Blast P3 American Thumper-Cycle related questions, technical discussions, and information. Come on in and get some THUMP! : ]

Owner's Manual
application/pdf
Blast Owner's Manual .pdf (590.9 k)

EZ

Got THUMP?


THUMPer Forum: The Buell Blast Forum on BadWeB (for Buell enthusiasts)



to store and compare Blast fuel economy.

Please feel free to add your data to the database. It's very easy and lets you track your mileage and compare to all other Blasts in the database. Please use your forum name when you enter your data.

This is a link to the Blast MPG Data Page

This is a link to the data entry form


Bookmark the form for ease of use.

Enjoy!


Please Note!!!!!!
We are in no way responsible for any damage that may occur in the advice given to help you fix or 'improve' your bike. We are here to try and help, but that does not make us libel for any actions resulting in that advice, you could easily go elsewhere and ask for other opinions, and act accordingly.
Thank you for understanding.

Just cuz - Manuals -
http://buellmods.com
EZ

  Thread Last Poster Posts Pages Last Post
Questions from New Buell Blast Riders - ThumperFAQMonzaracer1242 61 10-05-16  03:45 pm
Got Thump? (Buell Blast Photos)
For sharing photos of Buell Blast Motorcycles (Thumpers in the House)
Gearheaderiko3315 112 11-12-18  08:58 pm
Buell Blast Thumper Knowledge Vault
From Carbs to Customizing to High Performance & Racing - All the tech & tricks for Buell Blast Motorcycles, find advice & answers here - or post your questions!
Court26283 1521 01-27-19  01:00 pm
Buell Blast Racing!(and track days)Ezblast1001 40 04-05-18  11:02 pm
Thumper Tales (Tales From the Darkside!)
Ride Reports, Tales of Adventure, "Blasting on the Dark Side", & other stories of Buell Blast Thumpercycling.
Ezblast1845 67 09-02-17  02:02 am
Buell Blast Recalls, Tech Bulletins, Notices, & Concerns
The Buell BLAST! is a great motorcycle, however no bike is perfect - here is a place to post official recalls, tech bulletins, notices, and concerns related to the Buell Blast.
Anthony0267227 06-16-16  09:04 am
Blasting Around (Buell Blast Riding Groups)
Local and regional forums for meeting, greeting, and riding with fellow Buell Blasters (Thumpaholics)
Kenny_gilgore600 100 12-12-18  09:05 am
Pay It Forward: Blasting Goodness! (Trades Welcome!)
Pay It Forward - Buell Blast Parts & Gear: For assistance or to help your fellow Buell Blast riders when in need.



Kennyd331 14 06-14-16  05:13 pm
Buell Blast Motorcycle Classifieds...
Buell Blast Motorcycles, Parts, Gear, Accessories - For Sale or Wanted
2008xb12scg2667 561 08-22-18  04:29 pm
Blastphemy!
For non Buell discussions, questions or pictures that do not pertain to Buell.
Court424 14 03-05-17  06:51 pm
ArchivesEzblast16880 578 11-06-16  02:09 am
Archive through February 06, 201907blast30 02-06-19  12:51 am
Archive through January 16, 2019Natexlh100030 01-16-19  01:53 pm
Blasting Away - The Thumper Quick board
For unique exploration of ideas involving our Thumper!
Titusand7123 699 09-15-18  11:36 pm
Archive through November 26, 2017Salvatorejrm30 11-26-17  09:18 am
Archive through September 20, 2017Crackhead30 09-20-17  04:46 pm
Archive through June 01, 2017Slideways30 06-01-17  05:26 am
BLASTARDS ARE WE
Who we are and what makes us tick!
Please feel free to add to the list!
Gearheaderiko493 18 02-27-17  01:08 pm
Archive through February 04, 2017Ezblast30 02-04-17  01:29 am
         

Please visit the "Got Thump?" section for pics of various Buell Blasts; check out our "Knowledge Vault" for Buell Blast technical questions, look in "Blasting Around" to find who is in your area for rides and "hi!"'s; visit "Blasting Away" to see unique ideas involving the Blast, and visit the "Dark Side" for tales of Blasting adventure! Post at the bottom of the page here for anything else or just to say hi! Welcome and enjoy! : )

Author Message
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07blast
Posted on Thursday, February 07, 2019 - 05:40 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Another stupid question,

My buddy apparently had some of the same issues I had with his Honda Rebel turns out his pilot jet was clogged.

There was a jet that was sitting down in a tube and I didn't have a screw driver small enough to get in there when I first tore open the carb.

I was able to remove it now and I tried running a paper clip through it but wouldn't go through the jet maybe a quarter of the way down. I can go in from the bottom too but still won't feed all the way threw. There's a tiny, tiny opening that I was able to spray carb cleaner through.

I ended up taking the wire from a bread tie which fed through the jet.

Is it clogged or is that the way it's supposed to be?
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Missionbolts
Posted on Thursday, February 07, 2019 - 12:28 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

07Blast,

If it was clogged, it's not now! Good that you checked it out

But, the hole inside those jets has a very high-precision surface, and the jet is made from a relatively soft material, so I would be a bit worried you may have scratched the inside of it

The upstream end of the hole(facing downwards at the float bowl, fuel flows upwards into that when the engine is running) has a long taper that very smoothly reduces in size to it's rated diameter. That's why the paperclip could go in as far as it did. The taper is designed so that there's no turbulence in the fuel flow just before it reaches the orifice. Even the downstream end is important, as that has a taper also which is designed to help transition the flow into the much larger fuel passage that the jet is installed in

I've done some experiments with cutting notches in the downstream side of secondary venturis, and I've seen that the turbulence created by those notches will reach back upstream anywhere's from 1/4 to 1/3 of the venturis length, depending on how it's shaped. The flow indicator that allowed me to see what was happening was the fuel which had previously been pouring down the center of the venturi in a tight stream like a waterfall. After I added the notches, that fuel flow was shattered into a fine mist that mixed more evenly into the air running through the carb. The engine I was working on ran a lot smoother after I added the notches, picked up a couple horsepower and got one more mile per gallon. It was a 1.8 litre 4-cylinder

Hopefully, you were not putting too much force into that? The paperclip was too large, even for a brand new jet. The bread tie uses a much thinner steel wire. But even if that's small enough, it still has sharp edges on the end of the wire that can dig up furrows into the brass, leaving scratches that can cause tiny little vortex zones inside the jet. That will make the jet act like it's smaller

I would smooth off the end of the breadtie wire on a honing stone until it's perfectly round without any points that could dig, before using that to clear out a jet. The breadtie uses a very soft steel, so it's very easy to round off. Then I would put a drop of acetone mixed with motor oil inside the jet before using the wire to help soften up any varnish that might be there

Whenever possible, I will use a toothpick or a sliver of pine 2x4, as wood is too soft to damage the brass. I chuck that in a drill and hold it up to a sanding disk in order to put a very fine taper on it that can reach all the way through the jet. I never push sideways when running that into the jet, as it can break. The wood will have small fibers sticking out that act like a bristle brush. So I just run it straight down into the jet and let the solvents take care of breaking up the varnish

Nowdays, I have a $80 chinese ultrasonic cleaning tank that works very well for carb cleaning. I fill the tank with straight water & use small ziplock bags with a tablespoon of carb cleaner for all the little stuff. A gallon size bag will usually work for a bike carb

For the moment, it might not matter too much as you're still just trying to get the bike to run reliably. If the jet is altered, it's just going to throw the tuning out of whack but not actually break the bike
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07blast
Posted on Thursday, February 07, 2019 - 03:08 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Alright. I'm gonna put that back on and see what happens.

Also should note that when I pulled the carb off this time it had gas in the float bowl. I don't know why it didn't the first time I removed it.

Since gas is reaching the bowl can I rule out a fuel delivery issue?
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Missionbolts
Posted on Thursday, February 07, 2019 - 11:56 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

07Blast,

Sure, for now don't worry about the fuel supply. Maybe you shut the tank valve off, then ran the engine until it died? Which is a good thing to do whenever you put the bike away for a while. Most gasoline has alcohol, and when the bike sits long enough, that alcohol sucks moisture out of the air until it separates out from the fuel. Inside the carb, this means there's a pool of water at the bottom of the bowl where the jets are at, so the bike wont start. When I forget to run the carb dry and it's not starting, I just put the bike on it's side to let the fuel run out of the carb vents. When I put the bike back upright, fresh gas refills the carb and it starts right up. It's only goofy because somebody forgot to install a bowl drain screw when they were designing this bike
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07blast
Posted on Friday, February 08, 2019 - 12:38 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Yeah it's a goofy bike.

Haven't had time to reattach everything yet but hopefully all's good.

Also one for question for now. I bought a new air filter. I got a K&N high-performance air filter on Amazon (because 2-day shippimg)

Will that make the bike run lean?
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Missionbolts
Posted on Friday, February 08, 2019 - 12:58 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

07Blast,

I would hope that K&N filter does make it run lean!

That's what I'm running on mine. Instead of buying a jet kit, I just raised the float level. Runs just fine like that, not counting the oil loss issue. It gets up to 85 on a flat, which I think is decent for not having any rpm's to work with

I think the stock power is something under 30HP. It might not get going very quickly, but it feels very capable while dragging footpegs at 50
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07blast
Posted on Friday, February 08, 2019 - 01:06 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Again I know absolutely nothing.

Couldn't you also use the mixture screw to balance it put or am I gonna have to change the float level?

I wanna keep things simple you know
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Missionbolts
Posted on Friday, February 08, 2019 - 01:28 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Mixture screw only affects the idle, it wont do anything for riding around

While raising the float level will make everything richer. Though not necessarily in a neat & tidy manner

I don't remember if I also raised the main needle. That's something I would do in this sort of situation

The needle is inside the slide, which means taking the top of the carb off and dealing with not putting any holes in the diaphragm, removing a small locking clip deep inside the slide and dumping the needle out. Then if your lucky, the needle will have 5 grooves with a cir-clip in the middle groove. Moving that clip to the groove below will raise the needle a noticeable amount

Sometimes, it's easier to put the needle back with the slide all the way in the carb. But I'm thinking of some Honda carbs that are designed a lot differently

Normally you would change out the jets to a larger size. That K&N filter is pretty popular, so the best choice in jet sizes has been worked out. You could try searching here or on other forums for that filter on a Blast engine & see what jets sizes are the commonest used. Changing them is doing pretty much what you just did already

I only mentioned the float level hack because I'm an obstinate blastard
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07blast
Posted on Friday, February 08, 2019 - 02:12 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Again some more stupid questions.

The bike can still run if it's lean right?

Will that cause any damage to any part of the bike if I ran that way until I can get the jets?
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Missionbolts
Posted on Friday, February 08, 2019 - 02:32 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

If it's just the filter making it lean and nothing else, then it shouldn't be all that seriously leaned out. So it should run. I would warm the engine up all the way, do one good full-throttle run in 4th. then take the tank off and pull the sparkplug to see if the insulator is looking ok. If it looks a bit too clean, it's getting too lean to ignore. If there's any tiny dots across the insulator, that droplets of aluminum melted off of the piston or head. In that case I would stop running the engine until something is changed. But I've never had an engine get that bad. It will run weird long before

So it depends on just how lean, but in a worst case, yes it can do some serious damage

In your case, I think you could test ride without breaking it, but you should be cautious. Don't go on a hour long ride into the middle of nowhere, don't go that fast for any length of time or ride it fast like the owner is chasing after you in his corvette. Look at the plug to see what it's doing. Look at the plug right now, to see where it's at in normalish condition. It ought to be a dark tan, brown or even a bit black. Actually, if it's looking like very black might be a good thing, as it was way too rich. Crusty black could be it's burning some oil, which is a different issue
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07blast
Posted on Friday, February 08, 2019 - 02:50 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Thanks for all the useful information!

But another stupid question, where's the insulator is that the rubber slevee on top of the plug?
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07blast
Posted on Friday, February 08, 2019 - 04:38 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Carb back on and gonna get a new spark plug tommorow just to be safe (I have yet to check the current plug).

Bike still has trouble starting. Kinda makes a click from the right side of the bike.

Here's a video:

https://youtu.be/LRIeYdA2JzM

It turns over but dies shortly after. I can still keep it running if given throttle but if I close the throttle it dies shortly after.

I really don't want to take it to a mechanic I'd rather fix myself so I can learn a thing or two
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Missionbolts
Posted on Saturday, February 09, 2019 - 03:42 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

07Blast,

Sparkplug insulator is the white ceramic that goes through the center of the sparkplug, into the combustion chamber. I had meant to look at the end that is inside the chamber, which means you would have to remove the plug to look at the insulator where it's in direct contact with the combustion gasses

Bummer the 1st problem is still there!

Listened to that video. It gives me the impression that maybe you should get a compression test!

But maybe the cold start valve is acting up

If you could temporarily install a different carb just to see what happens

There was someone else on here a while back with similar running issues. He got a new cold start valve assembly and I believe that fixed the problem. I don't know how exactly the valve was doing it, but his bike was running too fast

Makes me think maybe I ought to install a better carb, if mine ever gives me any troubles! Something made in Japan would be nice as I have tons of experience working with those
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07blast
Posted on Saturday, February 09, 2019 - 05:27 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Spark plug was pretty dark and sooty. Put a brand new one in. Bike started fine but still wouldn't idle. Adjusted idle screw a little and now it'll start and idle. Idle is still slow and rough I'll do further adjustment later and take it for a ride and see what happens. Might be getting better!
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Missionbolts
Posted on Saturday, February 09, 2019 - 09:44 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

07Blast,

The one thing we haven't gotten into is the possibility that the engine is getting too much fuel!

After one good run on the bike, take the sparkplug back out and see if it's turning black & sooty again. That would be a sign that it's running way too rich

It's possible that if the previous owner was making changes to the bike like that intake boot, maybe he put in some larger jets and didn't bother to confirm if they were the right size?

Did you happen to note any numbers on the jets when you had the carb apart?

And make sure the idle is up fast enough. The engine was designed for more airflow than what it typically sees in stock form

What that means is that the intake port is way too large. What happens at idle is that the air isn't moving fast enough each time the intake valve opens, so the air will reverse directions and flow backwards out through the carb for just a moment. You can see this happening when it's idling, if you have the airbox lid off. There will be visible fuel vapor puffing out in front of the carb about an inch or so. It's easier to see with the black airbox as a background. Because the air goes through the carb twice while idling, it picks up twice as much fuel, and will quickly foul the sparkplug & maybe cause the engine to stall out or run very rough

The factory fix was to bump up the recommended idle speed, as it would've cost too much to build new heads with smaller ports. The Blast was designed to be a low-cost entry level bike, so spending more on it was always out of the question

The factory recommended idle speed is: 1200 rpm's. On any normal bike, having the engine running that fast means your cruising down the street at 30MPH in 3rd gear, not sitting on the kickstand while you get your gloves on

You have to wait until the automatic cold start valve has fully finished doing it's thing, as it will increase the idle speed right off the bat. When the engine idle slows down, then the cold start is finished and you can set the speed at the idle speed screw, which is near the front of the carb and angled upwards

If you want to know more about why I think the intake port is too big, and see a super easy low-buck fix that I tried out on several engines with the same success every time: http://www.mototuneusa.com/power_news_--_think_fas t.htm - that and part two

There's a bunch of other interesting articles, like the super top secret correct way to break in a brand new engine. I still don't know what happened, but the guy who wrote all those articles stopped maintaining the website for 3 or 4 years, then came back with a totally different agenda. No more engine building or bike racing. It's all become something you would expect to see at a retirement home. Personally, I think he bit it really hard out on the track & bumped his head a good one. Really a shame as he never wrote all the stuff he knew already
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07blast
Posted on Sunday, February 10, 2019 - 03:37 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Took the bike out for about 50 miles. Seemed to run fine again (as far as I know of).

Pulled spark plug, the middle part is still pretty clean but there's a black ring around it but not as bad as the other plug.
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Missionbolts
Posted on Sunday, February 10, 2019 - 10:05 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

07Blast,

1st time you really ran this new air filter isn't it?

Could be it was a combination of clogged filter making the bike run too rich, which fouled that sparkplug, and then the idle mix may have been out of whack

Put another 300 miles on the bike, then look at that plug again. If you make any more adjustments on the idle mixture screw, only turn it 1/8 of a turn, then test it out on the road. You might have it pretty close right now

Is the black ring just on the threads? Or on the white ceramic core? It could be two different things going on with that. Running a little bit too rich, or burning a tiny bit of oil, or a little of both

If you could upload a small pic of the spark plug here, I would have a better idea. Something like 600 by 400 pixels is plenty big enough, if it's a closeup

Really odd that nobody else has chipped in, I'm not usually this right about things, for this long of a time...
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07blast
Posted on Monday, February 11, 2019 - 01:48 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

I already put the plug back in. It was only black up around the first tread or two the core was still white. I'll check again after another 300 miles.

Thanks again for the help!
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Missionbolts
Posted on Saturday, March 02, 2019 - 12:51 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Yup, hit another car with one of the bikes bolts, out on the highway again. This time, both bolts that hold the upper front engine mount to the head broke. One of the bolts stayed put, the other flew off

That engine mount has a tendency to flex in a vertical direction, rocking across those two bolts. The constant rocking put undue strain across the bolt shanks, they both snapped at the same exact depth inside their respective holes

Drilled, easy-outed & installed grade-5 cap head bolts with too much red loctite as per factory recommendation...

As a result of the engine dropping forwards and getting jiggy, the exhaust snapped in half right at the port. I think that's to be expected with the Blast?

Welded the pipe back together, again

Anyways, I noticed that without the exhaust system the bike was making a good bit more power. I'm thinking maybe it's time to do something better with that exhaust
 

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