Thread:

trouble shooting old sbc jet

Ive recently acquired a 19 foot jet (horizon) and the boat had been sitting for at least 4 years.anyways after redoing some of the plumbing and a carb rebuild got the boat to run and took it out today for maiden voyage. boat ran good for about 20 min. then started cutting out and finally died. after sitting for about 20 more min started right up and proceeded to run good again for about 20 min then died again. does anybody have any idea whats going on? have right water press. good oil press. boat was running kinda cold 125. any help would be greatly appreciated. thanks, Danny

Originally Posted by jetboatperformance

Spark ? fuel to the carb ? old gas ? what did you do to it (after setting) before you drove it ?

thanks for your input. I cleaned the fuel tank but it didnt occur to me to look for fuel filter. ill try that next. after sitting i had the carb rebuilt , changed the plugs and rerouted the plumbing (it was a mess) put a pressure "t" valve to control water to headers and added a second dump line to lower water press. in the motor. and did oil change. thanks in advance. i forgot to ask ... do i need to have a water pressure regulator on the line going into the motor? is that what helps the temp run where its supposed to be? cuz it was only running at 120 degrees thanks again, Danny

Originally Posted by Moneypit

The Engine temp didn't make it die..... You might be leaving a little bit of HP on the table at that temp, but it should still run fine... In addition to your fuel filters, make sure the tanks are venting properly..... If it vents through the flip up caps they can get clogged full of crap and create a vacuum the pump can't over come...Let it sit for a while and the vacuum dissipates and it starts back up..... Good luck,
Ray
PS If it happens again, first check for spark from the coil.... A bad coil could do what you're getting..

Thanks for the input moneypit ,im gonna take it out again next week and try the recommendations

It is an ignition issue! Older boat with older system? Ballast resister!!! That white ceramic block. they get hot and break down. take along a jumper wire and when it acts up jump the resister and see what happens. Mark

Originally Posted by ol guy

It is an ignition issue! Older boat with older system? Ballast resister!!! That white ceramic block. they get hot and break down. take along a jumper wire and when it acts up jump the resister and see what happens. Mark

thank you to all of you who have taken time out to help me . after i run the boat again ill post my results, Dan