blown up!

[05blasterkid]

Well I rebuilt my blaster in august, had it done in august and I rode it twice and it blew up again =(. The reason it blew up was because it was running lean and I couldn't tell it was because we were running premix and oil injection for the first ride so the plug was black and for the second and final ride we just ran premix but there was still more oil in there so it was still running rich so the plug wouldn't tell me anything. The second ride it was running fine for a while then the plug starting fouling out, so we replaced it and it ran beautiful. Then we were going up a rode and I held it wide open and it quit. It still felt like it had good compression so I didn't think it was blown I just figured the plug was fouled. So I got a new plug and bigger main jet and just to be safe took the top part of the cylinder off and the piston was cooked on the exhaust port side (lean) so yea, I don't think the cylinder is bad but we will find out but gotta rebuild it again

 

[Awk08]

who's birdbrain idea was it to run the injection and pre-mix ?????
did you do the required leakdown test, heat cycles, and a few hours of easy riding for break-in ????
and what about proper warm-ups before riding ???
what other mods did you do that required rejetting ????

 

[darederek]

awk he had a thread about running premix and oil injection at the same time and everyone and their mother told him not to but his hard skulled dad insisted because some random guy told him to do this for their boat motor

 

[Whitty21]

tell your dad there is more knowlege on this site than every man that his father has looked at in his entire life. awk raises good questions though, answer them all and we can diagnose the problem, what jetting are you rinning?

 

[05blasterkid]

I didn't do a leakdown test, I did heat cycles and a few hours of easy riding, I did warm it up before riding I'm not sure if it was proper but I did warm it up. I have a uni air filter, boysen reeds, and a toomey exhaust kit and I'm running a 310 main jet. Like darederek said I ran both because my dad wanted to and I can't change his mind, and I asked around 3 local shops (lanes yamaha, m&a cycles, and 6th gear motorsports) and they all said that ikt wouldn't hurt anything to run both, the only thing it would do is foul plugs

 

[79 bronco]

Wow he ran the injection and pre-mix, that is a lot of oil...The more oil you run the less gas the motor gets, the less gas the motor gets the leaner it's running....That poor motor was Fu@#ed at the start...

 

[Awk08]

/\/\/\/\ very good point 79, plus lowered the octane of the fuel, which prolly ran it too hot, but your jetting should be close, definately invest in a leakdown tester, unless you have a garage full of spare pistons and cylinders
and i never run wot for long runs, especially on a new motor

 

[hudack]

/\/\/\/\ very good point 79, plus lowered the octane of the fuel, which prolly ran it too hot, but your jetting should be close, definately invest in a leakdown tester, unless you have a garage full of spare pistons and cylinders
and i never run wot for long runs, especially on a new motor

yes invest in a leakdown tester im going to very soon luckly i know a guy who lives close by with one and when u rebuild it leakdown test if thats good heat cycles once ur done with that treat it like a new born baby i run 2 tanks of gas outa mine b4 i beat on it again

 

[royalt67]

Wow he ran the injection and pre-mix, that is a lot of oil...The more oil you run the less gas the motor gets, the less gas the motor gets the leaner it's running....That poor motor was Fu@#ed at the start...

I would question whether the extra oil from the injection leaned it out. After all, only the oil in the pre-mix would affect the jetting. Still, 32:1 premix should have been fine for oil, the injection would just be fouling it like his mechanics said.

A 310 should be plenty large, jet wise, but with the fouling from the extra fual, how would you ever be able to check? Doing a leakdown test this time is a must (like the other guys said) that lean condition is probably caused by a mechanical problem, not jetting.

 

[BlasterHoss02]

Pick one because ur wastin oil and risking ur motor. i would def. premix i dnt trust the injection at all.

 

[2stroke4ever]

i'm a marine tech and i've never ever heard of running extra oil on a break in on a outboard or a jet ski, what a great way to gum a motor up and not have your rings seat properly, plus your stuffin a ton of oil through your carb which i would imagine requires different jetting beings most jettin advice isn't based on what your doin, i would imagine it would greatly affect the way the fuel is atomized and how it burns or doesn't for that matter, if your running good oil there is no reason on earth to be running that much of it, i've heard of people staying away from full synthetics during break in but i guess i don't recomend it and neither does yamaha or mercury's outboard tech lines or kawasaki's tech line, but hey leason learned, hopefully