View Full Version : Blast Help - New Owner

Paul S
03-15-2015, 03:13 AM
Hi there,
I recently purchased a clean 09 Blast with 1800 miles. I was planning on doing a full service on it but wanted to ride it a little to see how it ran. It started and idled well. I checked the oil when cold (I later read where it should be checked hot) and it was about 2/3 qt. low so I topped it off with Mobile 1 20/50 and took off on some errand running.
Temp was about 60 degrees f. I drove it about 100 miles and the bike ran strong and flawlessly. Just as I was getting close to home at about 60mph the bike started losing power and then died all within about 45 seconds. No weird noises or anything. I pushed it on home. I still had gas to the carb, had good spark, and battery still had juice. I put a compression tester on it and with the throttle open i had 30psi on the first crank which worked itself up to just shy of 120psi by the 7th to 8th crank. I injected 1/2 oz of oil and got a final reading of about 160-170 psi. I then placed the plug in it and it started and ran about 45 seconds then died at which time the compression readings were back around 120psi. What has happened? Thanks for the input.

03-15-2015, 06:21 AM
Check for air leaks. Did you have a boot come loose?

Paul S
03-15-2015, 02:05 PM
No problems that I can tell in that area. There did not seem to be any symptoms of an intake leak mentioned in other posts. Thanks

03-16-2015, 07:04 PM
120psi is too low, likely lost a ring from running too lean.

Pull the head and check the bore for scratches.

Paul S
03-16-2015, 11:55 PM
Thanks much, that seems to explain the quick turn of events. I'll be getting a new boot to be sure.

Paul S
03-17-2015, 02:45 AM
After seeing what is going to have to be mended in the top end...

Paul S
03-20-2015, 07:26 PM
I pulled the head, jug, and piston today. To my untrained eye everything looked okay except the top of the piston and the combustion chamber had a lot of carbon build up (in my opinion). The cylinder lining looked good but I will have a mechanic check it out. At 1800 miles do you think this is worn rings from running lean or maybe a stuck ring? The boot had some cracking but didn't appear to go all the way through. Thanks for the input.

03-21-2015, 12:47 AM
The boot had some cracking but didn't appear to go all the way through.
Any cracks go all the way through and caused your lean condition. Replace it.

After it is inspected, ask for a light hone and new rings. Since the oil brought the compression test up to spec, I suspect it was a ring.

Paul S
03-21-2015, 12:51 AM
I appreciate the info and will do. You guys are golden for your time and effort :)

Paul S
04-07-2015, 02:41 AM
Well this was a discouraging day. The other day I had a mechanic look at the cylinder and head. He said with the old rings everything was in tolerance and the valves were both good. He gave the cylinder a hone and cleaned up the piston, valve seats, etc. I put the bike back together with new rings, gaskets, etc and bought a super boot as well. I did a quick inspection of the bottom end of the carb and sprayed some carb cleaner through it. Finally got everything assembled and started it and it ran for a minute or so and then started the same nonsense. It would barely idle then die. I didn't even get down the driveway. Now I'm banging my head.

04-07-2015, 04:53 PM
I bought a 2009 blast last year. About the same miles as you. It ran about 100 kms and stopped.
This bike was clean as a whistle inside and out. I would start it. I would run for 20 seconds and stop. Then a day later try again, same thing.
Turned out to be a bad 'Bank Angle Sensor'. Simple safety switch. Geez.
This is what happened to me. Just throwing it out there. Don't be discouraged.
I did go out and buy everything the Dan/Thumpe had to offer ; -). Love this bike.

04-07-2015, 06:50 PM
What was your compression after the rebuild?

If everything was fine, then you wouldn't have 120psi compression. Moreover, your compression wouldn't have increased to 170psi with the addition of oil. That is THE test to check for failing rings.

Paul S
04-08-2015, 02:09 AM
Thanks, I'll look into the sensor issue if I can't narrow it down to another issue. As far as the compression I have not rechecked it yet but with new rings it shouldn't be a problem. I'm wondering if my compression gauge might be faulty? If I get the same reading I'll borrow another gauge. I did get the k&n and elbow from Dan with the right jet and it really cleans up the look of the little bike. I really like it and hope I can get this figured out. Thanks again guys for the input and I'll update when I get time to tinker with it. Paul

04-08-2015, 02:59 AM
paul: i'm probably being over-simplistic here...but could it be running out of fuel....as in dry float bowl? i've never owned or worked on a blast but why not try running it again and when it shuts off fog the carb and see if it comes back to life. if it does i would tend to think it's a fuel delivery issue. just a thought.

04-10-2015, 01:09 AM
Hello- Bought a 2002 Blast w/4700 miles on it. Having same problems as all the post also. I static timed the bike but no red LED illuminated. Did what the manual said and aligned the / mark center hole. I next aligned the 2 ** in the view hole and got a LED illumination. It would stay illuminated even when advancing it or retarding it. Any ideas as to the module being bad?? Thanks any help would be appreciated

Paul S
04-13-2015, 02:27 AM
Well, lunaticfringe hit the nail on the head. I had some fuel in the tank and when I popped the fuel line off gas ran out of the line, but not the tank. I put it on reserve and just a trickle. I added fuel and it ran like a champ. I rode for about 30 miles with a relieved grin on my face. I guess it's time to clean out the fuel screen; boy I feel like a genius. Anyway, thanks to everyone that contributes to these forums, I feel like I have learned the ins and outs of the blast and feel I can keep one going for many miles. Thanks again. Paul

04-13-2015, 03:50 AM
there is a reason that John has 300+ rep points. :D

Paul S
05-04-2015, 02:19 AM
Just a quick update. I took the tank strainer out and it was clean, but I guess I must have had a quarter tank of water which is why the bike would stop running at about 85 miles when I still had plenty of gas (& water). I refilled with fresh gas and all seems well finally.