Super Jet turns over without spark plugs only. WTf?

[mademan9]

So I have a fresh new motor from Jetmaniac and just finished putting everything together . Now time to start motor. SPark plugs in, tank filled up and start!!! Nope. it turns over a half a resolution and the bendix sounds like it disengages. ok no biggy. open the cold fusion flywheel cover and i forgot the spring for the bendix. problem fixed? everything back together , push start and it does the same thing. i then pulled the spark plugs and pushed the start button. it spends perfect.

So theres the story , what do you guys think it is?uppy_dog_eyes: I put back and took out the spark plugs a couple of times to see if there where any changes. still nothing.

thanks for the help

 

[waxhead]

Slipping clutch in the starter bendix

 

[MADMAT]

Chitty battery?

 

[Matt_E]

Bendix, as suggested, or a weak starter. (or weak cabling to the starter, bad ground,.etc)

 

[FlightPlanDan]

Bad starter or power cable connections?

 

[Boris]

Check your battery voltage while you crank.

 

[cattledog]

if you have a voltage tester the reading should be higher than 12 volts 12,5 or over is ideal, put a another ground wire from battery to any flywheel cover bolt just in case you have a bad ground

 

[mademan9]

Chitty battery?

nope battery is new and charged up

 

[mademan9]

would it still be the battery, if it turns over great when no spark plugs????

 

[steve-uk]

could be cos its running without compression so its less work for the battery

 

[mademan9]

if you have a voltage tester the reading should be higher than 12 volts 12,5 or over is ideal, put a another ground wire from battery to any flywheel cover bolt just in case you have a bad ground

ill have to do that tomorrow, tester is at my office. ill try the ground wire on fly wheel

 

[Boris]

Check your battery voltage while you crank.

If the battery is strong and charged, all your connections A-OK than more than likely it will be your starter.
Pull it out, stick it in a vice and hook it up to a battery with some jumper cables.
As it spins stick a piece of 2x4 onto the splines and try to stop it.
A good starter motor will just make splinters out of the 2x4, a bad one will slow down and stop.

 

[Waternut]

I vote starter as well. After sitting for a while, corrosion can eat at the contacts attaching the brushes and cause them to crack and split. I've pulled apart 3 faulty/weak starter motors from kawi's and SJ's. They all fail in the same place and they all typically work poorly at first and then just completely die when the current melts the last little piece of metal.

 

[mademan9]

I pulled the starter early today and cleaned it pretty good. It looks great but i know looks can be deceiving. I tried it on the battery , it spun good. I didn't put it in a bid so I'll try that tomorrow.

 

[Proformance1]

Easy way to test ground is grab a set of jumper cables and hook one side to the neg on battery and the other end to the motor someplace. If it fires you already know whats wrong.

 

[cattledog]

try the cable now if you have cables i wont be able to sleep tonite knowing the ski wont start , by the way i just read your whole build thread ,great read, good luck keep us posted

 

[WILKEY]

hahaha mario

 

[mademan9]

try the cable now if you have cables i wont be able to sleep tonite knowing the ski wont start , by the way i just read your whole build thread ,great read, good luck keep us posted

Lol. I can't man the neighbors. The cables I have are to big to fit around the battery screw.

 

[Algonquin]

I'm guessing the motor spins half a revolution then stops, then you wait for the starter to stop, then hit the button again and it does the same thing, over and over.

Then its the bendix. Guaranteed.

The above procedure rules out the battery, connections, and most likely the starter.

The bendix may look fine, but one of the weights inside dislodged. It will still most likely retract like normal in your hand etc., but it is shot.

 

[mademan9]

That's exactly right. Damn I didn't want to hear that. I'll try all the other stuff, but I think it MIT the bendix