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Diagnosing Problems / Causes / Intake Boot (Das Boot!)

This is a summation of several posts on BadWeb (thanks to all)

The Blast has a vacuum operated carburetor. The intake boot transfers vacuum created from the stroke of the cylinder. The Blasts carburetor is basically suspended by the intake boot and the air filter compartment. It is subjected to a large amount of vibration, and as it gets older, it starts to crack, allowing the vacuum to escape robbing your carburetor of the proper air & fuel mixture necessary to run your bike well

Intake Boot Symptoms (Smallest to Largest) :

*) Flat Power Loss - If you are experiencing loss of power while riding flat, not under load, not going up a hill or a steep grade
*) Small increases in fuel efficiency - Do you normally get 65 to 70 miles per gallon, and now it seems your getting 70 to 75
*) Do you have random power loss followed by backfire, then a regain in power
*) Bike will not start, will turn over, but will not start
*) Will idle but dies when you apply throttle.

*) Make sure it is not a gas tank vacuum issue, try to start your bike with the gas cap off (If no continue)
*) Have you checked your fuel is on, the fuel filter &main line into your carburetor? (If yes continue)
*) Are you getting consistent spark from your plug? (If yes continue)
*) Place your hand over your carburetor while attempting to start the engine. You should feel strong suction on your hand, (If not continue)
*) Replace intake boot

Replacement at a garage will run you just under $170, 2 hours labor + part, the part is about $10.00 retail and very easy to replace. Following the Service Manual instructions for checking fuel filter and removing carburetor will get you all the disassembly and reassembly instructions. Be sure you have the boot seated in the grooves correctly, and that the clamps are in the correct grooves and tighten sufficiently.

NOTE: I noticed the smaller issues for about a month before my boot issue got to the point my bike would not start. It has also been suggested that you regularly change the intake boot at least every 2 years.

For resolving the issue:
Yes - but also check your front and rear grounds and battery connections. doing the boot is simple:
To replace the "Boot" (Manifold-Carb Coupler),you need to loosen both sides of
the airbox first....then you can pull the airbox with the carb attached - a
little bit away -so THEN you can pop out the Boot ! Ok- on the left side of the
airbox lower down- you locate and remove the TWO bolts that hold the airbox to
the triangular bracket that bolts to the block- But DO NOT remove that Third
Bolt that holds the bracket to the engine block- that one remains intact ! Then
on the right side of the airbox, remove the one bolt that goes thru that small
metal tab on the underside of the airbox- that attaches it to the engine block..
after that- the box and carb are free to move enough to safely pop off the
intake boot (manifold connector) and replace with a NEW one. Now time to button
it back up. When you're done snugging up the boot clamps(don't overtighten and
shread the rubber!) you Then use "Blue" loctite on the CLEANED threads on the
lower right side bolt and tighten snugly (the Torque is 10-12 ft lbs)-don't
strip the aluminum threads in the block. On the left side, the bolts insert
into a brass(threaded) insert into the airbox, just use ONE drop of (low
strength)"Purple" loctite on THOSE cleaned threads, and snug them up(Torque is
3-5 ft lbs)- but don't strip by over tightening. And thats all there IS to it!

Bank Angle Sensor (BAS) safety switch bypass:

The BAS has 3 wires going to it. The white wire with a black stripe is "hot" or positive. Double check it to be sure you have the correct wire. It is the only one that is "hot". Do nothing with this wire.

The other two wires should be connected together.

You must check the Bank Angle Sensor (BAS) safety switch too. It's a common culprit of intermittent problems. When working properly, the 3 wires will show 1 hot (white w/black stripe) and 2 ground. If one wire does not show ground the switch has been tripped and will not (or should not!) reset until the ignition is turned off. If after the ignition is turned back on the 2 wires should show ground. If not, it's bad.
For anyone wanting to get rid of their BAS switch. Cut it off and connect the green/yellow wire with the tan/yellow wire and cap off the third wire.
You can plug it back into the BAS or leave the BAS plug hanging. And......If the BAS is bad, the LED on the module will still flash.

For kick stand bypass - twist wires together.

Clutch Diode - middle diode - Flip - link:

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Posted on Tuesday, July 23, 2013 - 01:16 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

The blast ran great till about 3 weeks ago. Use needle has been shimed, air mixture screw has been drilled out and adjusted. The carbs been rejetted to you and Ez's recommendations. The carb work has been done for over 3 years. The intake was done at the same time. I'm still having problems uploading a pic, I got the image size right but the file size is too big. I will another approach tonight after work.
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Posted on Wednesday, July 24, 2013 - 08:23 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Bad gas?
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Posted on Monday, July 29, 2013 - 02:40 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)


You can check the diaphragm. Also check the vacuum plug on the carb-if it has one-the cap can crack.

I assume you mean low rpms? Clogged slow jet is a good assumption, but I think it would have hard starting and poor idle too.

Bad ignition parts will cause you hair loss. Usually its high rpms, but low speed lugging will cause them to act up. Its far often the module going bad than the coil. The module can also act erratically in symptoms.

Loose plug wire or spark plug nipple is a possibility.

Bad plug wire.

Since you havent done anything recently, I'm going to assume this is a completely new problem unrelated to anything that might have recently been done.
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Posted on Saturday, November 21, 2015 - 02:12 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

So I am new to the whole motorcycle thing. I recently picked up a Blast as my first bike and it has problems that I've been tinkering with. Anyway it is missing the bolt for the air box that goes into the engine I think? Is this a big deal to be missing? This bike is actually missing a ton of the hardware.
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Posted on Saturday, November 21, 2015 - 03:30 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

No, not a big deal, but it should be replaced. A ton of hardware sounds bad :-(

DO NOT TAKE THE CARB APART "to give it a good cleaning"! Please!

....and Welcome: )
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Posted on Sunday, June 12, 2016 - 10:09 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Wait, what bolt?

There's 4 holes from the airbox to the carb, but only 3 require a bolt. The 4th (top left) is a vent for the bowl.
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Posted on Tuesday, June 14, 2016 - 12:10 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Erik, did you post that in the wrong sub-forum? lol
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Posted on Tuesday, June 14, 2016 - 12:42 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

How in the heck did that happen?

Crap, I'm REALLY old!!
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