SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: SuperDuty on June 21, 2010, 07:03:28 PM

Title: Engine Tune Up
Post by: SuperDuty on June 21, 2010, 07:03:28 PM
So I took the V-Drive to the lake the last few weekends cause my jet is nowhere near being ready for the water. This last time the 390 had a pretty bad miss at high RPMs and wasnt really wanting to idle. I decided it was time for a tune up before next weekend to see if that helps her out any. So Im doing the standard plugs and wires and hitting her with a timing light. What else should I be checking or replacing? I know its hard to take a guess with such little info about the miss, but it has fresh gas on a newly rebuild carb. Any general ideas? Thanks!
Title: Re: Engine Tune Up
Post by: electrowoman on June 24, 2010, 09:06:42 AM
Does it have a vacuum gauge?   One other thing a friend told me to try...  have your wife
or girl friend hold a plug wire while you crank it over.

If she screams and chases you two blocks spark is good
If she curses and walks away check for weak spark

 ;D
Title: Re: Engine Tune Up
Post by: GT Jets on June 24, 2010, 09:09:21 AM
Does it have a vacuum gauge?   One other thing a friend told me to try...  have your wife
or girl friend hold a plug wire while you crank it over.

If she screams and chases you two blocks spark is good
If she curses and walks away check for weak spark

 ;D

 :thumbup: :thumbup: ;D, spit coffee on my laptop screen...

GT
Title: Re: Engine Tune Up
Post by: River Roy on June 24, 2010, 10:02:43 AM
Does it have a vacuum gauge?   One other thing a friend told me to try...  have your wife
or girl friend hold a plug wire while you crank it over.

If she screams and chases you two blocks spark is good
If she curses and walks away check for weak spark

 ;D

Did that way of spark testing with my little sister and a mini-bike 35 years ago, She still remembers and is still mad about it. >:D >:D...RR
Title: Re: Engine Tune Up
Post by: FordLover on June 24, 2010, 10:17:01 AM
Every one is staring at me while at work because I just laughed out loud.  That sh!t was funny AND effective.
Title: Re: Engine Tune Up
Post by: 76NORDIC on June 24, 2010, 10:25:50 AM
That was frickin hilarious :thumbup: :thumbup:Reminds me of the time I was working on my 70 firebird, had a fiberglass hood on it so i used a stick to hold the hood up. Was working on it while it was running, and reached across to make an adjustment, and so happened to lay my arm across the Mallory High voltage coil :screwy: Shocked the living crap outta me, and as I jolted up, hit my head on the hood, and of course knocked the stick out, I am now stuck under the hodd with the motor still running :banghead: :banghead: :banghead:    Thread jack over ;D
Title: Re: Engine Tune Up
Post by: SuperDuty on June 24, 2010, 12:38:22 PM
Been there! Done that. Im the youngest, big brother loved having me check spark on his dirt bikes growing up. I stopped that when he had me test the 72 bronco. Well, I threw new plugs in her.. still running rough. I did find out that the squiter for the secondarys had some crap in it and wasnt working. Float level was too high. On the pavement it was fine, but if you were to shake the boat even a little gas would overflow into the carb. That was my main problem while running I think. Also found that my distributor cap was broken. The post that comes in from the coil was broken off so the spark had to jump. She runs great on the hose (like usual) so Ill have to take her out and see what the lake does. Thanks for the ideas!
Title: Re: Engine Tune Up
Post by: SS-201 on June 25, 2010, 03:59:16 AM
I would check the fuel bowls for gelled gas from sitting with ethonol doesn't take long or as least run some gas stabalizer thru.
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