NEED HELP PLEASE CARB OR ELECTRICAL?

Patg

New Member
Oct 29, 2014
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I bought a Yamaha blaster not running that needed reeds I put new reeds in it and it had no power it would run but it wouldn't have throttle response it would turn on and rev up and down but as a delay so then I would try and drive it and it would go only go like a mile an hour after that I found out it was the crankshaft seal so now it was good it has a full fmf pipe and silencer and a k&n filter it has a 320 main with a 40 piolet clip on 3 and 2 turns out. It ran fine but then one day when I was riding it slowly died down and died I was in 3rd and I pulled the plug out and it seem to be flooded so I put a brand-new spark plug in and now once in a while I can get it started but it won't stay on very well even if I'm giving gas. Could it be the coil? Here's a video on me trying to start it too. Please help thank u
 
IF, you've tested for good strong blue spark.....i'm voting carb

you say it has a 40 pilot ?
that would be a problem, i've never seen any stage of blaster modification that needed anything other than the stock 32.5 pilot jet in the stock carb, start with the airscrew at 1.5 turns out and tune the airscrew like this.....

http://www.blasterforum.com/threads/adjusting-your-airscrew-pilot-jet.51060/

set your float level while you're in there....
http://www.blasterforum.com/threads/float-heights-and-how-to-adjust-them.50565/

also....new NGK b8es plug and check the flywheel keyway (woodruff key) has broken,
allowing the flywheel/timing to move off TDC
 
Do you have an air boxlid on? Have you done a plug chop? What temp/ elevation are you at? 320 could be to large for your mods
 
Looks like you got an exhaust leak too. (.20 .41 big one at .48 seconds) Can you pull exhaust and see if there is something stuck in there. I have seen new reeds installed and not tightened enough with thread lock/lock tight and get sucked through. Always use a little thread lock when putting in new reeds.
 
Excessively rich jetting may have been to compensate for seal leak and now that leak is fixed it no longer needs that rich.

May pay to do a compression test to check for damage from bad seal. Then do leakdown test to be sure you have no other problems.
 
Those few times when it backfired where did the smoke come out? Jus me thought exhaust I thought it came out of your flywheel. If it is coming out of your stator you may have a bad seal on the crankshaft.

Backfiring is a sign of bad reeds or timing being off (like Awk said woodruff key).

Have you leak tested?
 
Just a guess but is carb clean as a whistle? I have seen jets completely close themselves off from sitting. Float pin needs to clean and move freely. Look for spark and work your down a list of problem areas. Intake, carb, reeds, throttle, etc..

Take off pipe and clean that area up to see why the exhaust cloud comes out where it did. Hope its not from the stator or jug base.