Yamaha 760 slow cranking, won't start...help please!!??

[LakeCreature]

Hi all, <br />I have a 1996 Yamaha Wave Blaster II 760. Late last summer, it wouldn't start ,just crankin...had new brushes put in the starter....and then it started(hard). Rode it a few times and then it just didn't seem to run right after dumping it. Put it away for the winter. <br /><br />Got it out this spring, new battery & plugs....won't start.. .cranking kinda slow. Pulled plugs and tried to start...got spark & not any sign of water...combustion good. Tried jumping with another battery, no change in cranking. <br /><br />Guys at the dealer said to check the pump to make sure nothing was wound around it, holding it up. Nothin there. Other than what we've checked so far they are stumped and said to bring it in. <br /><br />Any suggestions? Trying to fix this one myself. Not crazy about an open ended ticket at the dealer. Pulling my hair out here.<br /><br />Thanks in advance.

 

[Seaboo2]

Re: Yamaha 760 slow cranking, won't start...help please!!??

How's it crank with the plugs out? Still slow?? If so I'd check to make sure the pump (shaft, whatever you want to call it) doesn't have something wrapped in it (I know you said you did....Maybe a recheck). Check all connections from the battery post, starter lead, ground and make sure they are clean and getting good contact). Maybe you can disconnect the shaft and see if it turns easier (will help troubleshoot wiether it's engine or pump related).

 

[LakeCreature]

Re: Yamaha 760 slow cranking, won't start...help please!!??

There doesn't seem to be a way to disconnect the pump, that I can see....unless maybe pullling the motor. I can see right through it from the rear and underneath. <br />Cranked it with the plugs out and got plenty of spark, no change in cranking speed though. Did a voltage test on the cables and they are good, connections good. <br />I'm at a loss here......

 

[LakeCreature]

Re: Yamaha 760 slow cranking, won't start...help please!!??

Pulled the plugs and shot a little gas/oil mix in there.....after cranking a couple times it fired right up. Started it about five different times and revved it up...ran good, smoked a bunch. Let it sit about half hour and tried to start it again......just crankin like before. We do have a primer bulb on it but did not remove the choke.<br /><br />Marina's closed today, will pick up new plugs and fuel filter tomorrow.<br />Possibly its time to rebuild the carbs?

 

[SSRBBK]

Re: Yamaha 760 slow cranking, won't start...help please!!??

Originally posted by LakeCreature:<br /> Pulled the plugs and shot a little gas/oil mix in there.....after cranking a couple times it fired right up. Started it about five different times and revved it up...ran good, smoked a bunch. Let it sit about half hour and tried to start it again......just crankin like before. We do have a primer bulb on it but did not remove the choke.<br /><br />Marina's closed today, will pick up new plugs and fuel filter tomorrow.<br />Possibly its time to rebuild the carbs?

 

[SSRBBK]

Re: Yamaha 760 slow cranking, won't start...help please!!??

I had the same problem with a Tigershark. Mine turned out to be the forward piston skirt had broken off and was making the piston rub the cylinder. Also smoked like crazy. If you do a compression check and get more that a 10% difference in readings, wouldnt hurt to pull the head and see how the cylinders look. Other than that, check the starter gear bushing and make sure it isnt binding there. The best thing to do is a bench check of the starter to make sure its turning freely.