Anyone please help with my mercruiser 5.7 thunderbolt v igntion engine, hard to start

[rsxracing]

Hi. I have mercruiser 5.7 thunderbolt v ignition engine. I always have trouble starting it cold. I watched many videos how to start a and i do the pumping but my engine still take a long time to start. Once it start and runs for a little I can turn it off and it will start again with no problem. But Little cool down and then it hesitates again. There was also times even after running the engine a little as soon as I put on idle just to reverse my boat engine would also shut off.. this boat is stressing me out as alot of people say different things and not sure if I should replace the carb or dome other things

 

[alldodge]

Welcome
What is the motors serial number?

 

[JASinIL2006]

How long is "a long time"? When mine is cold and I'm starting it on muffs in the driveway, I sometimes will crank 30 seconds or more before it fires up. (Sometimes longer if it hasn't run in a while or it's cool out.)

Incidentally, that's why I always warm the engine before heading to the boat ramp; at the ramp, I want to fire up without delay.

 

[Scott Danforth]

I would start with simple maintenance and a choke adjustment.

Doubt you need a new carb

 

[flashback]

Yep, wether it's a brigs or a V8 it needs a proper tuneup..
AD gave me that one and it's true..

 

[Scott06]

When u pump the throttle to set the choke look down carb to see if any fuel is coming out of accelerator pump And if choke sets properl. If it has sat long enough carb can dry out and there is no fuel in carb until the engine turns over a bit.

is your ignition system in good state of tune ?

 

[rsxracing]

Welcome
What is the motors serial number?

 

[rsxracing]

Oko10977

 

[rsxracing]

How long is "a long time"? When mine is cold and I'm starting it on muffs in the driveway, I sometimes will crank 30 seconds or more before it fires up. (Sometimes longer if it hasn't run in a while or it's cool out.)

Incidentally, that's why I always warm the engine before heading to the boat ramp; at the ramp, I want to fire up without delay.

Up to a minute. But that shouldn't be normal to start it that long , shouldn't? There were times I gave up , didn't want to ruin the stater or kill batteries

 

[rsxracing]

I would start with simple maintenance and a choke adjustment.

Doubt you need a new

What you think I should do besides choke adjustment

 

[rsxracing]

Should I replace the the distributor along with spark plugs? When I pump fuel comes out. I had to change the choke at one point because something was wrong with it, I think the spring was messed up in it.

 

[rsxracing]

Also today it started better, ran for a little but as soon as I put it on neutral as you would to put on reverse it shuts off, when I restarted it hesitated more then the 1st try but started

 

[alldodge]

Think your main issue may be spark. The TBV ignition is a good solid system when it works.

The most problem cause for the lack of spark is the sensor 892150Q02 in the distributor and that's for the ones which have not had them replaced with new style. New ones have an additional wire which goes to ground

If you have a Alpha drive
The motor dying when going into reverse might be the shift interrupter. The interrupter may also be causing a problem with no start. Check the adjustment. You could disconnect one of the wires on it and see if it starts easier. Don't leave it off because you won't be able to get it back into neutral with boat in the water.

 

[Scott Danforth]

It's not the distributor, it could be the $50 sensor (hall-effect trigger) as AD mentioned

 

[rsxracing]

Thanks for your help all. Im not very much experienced with boats so I'll have to look into the shift interrupter.and how to adjust it. Yea its alpha drive. But the thing is I have no problem going reverse and forward gear but just when going into neutral the engine would die. But interesting thing the other day I ran the boat for some time and put it on neutral and it stayed running for good amount of time. The boat surprises me sometimes. One time it dies. One time it runs on neutral. One time is starts and then it hard to start it. Ones I'm running it it runs good. Also when i start it at home to warm it up the rpm would start going up on its own until I have to turn it down. Can there be problem with my throttle wiring or need adjusting ?

 

[alldodge]

Thanks for your help all. Im not very much experienced with boats so I'll have to look into the shift interrupter.and how to adjust it. Yea its alpha drive. But the thing is I have no problem going reverse and forward gear but just when going into neutral the engine would die. But interesting thing the other day I ran the boat for some time and put it on neutral and it stayed running for good amount of time. The boat surprises me sometimes. One time it dies. One time it runs on neutral. One time is starts and then it hard to start it. Ones I'm running it it runs good. Also when i start it at home to warm it up the rpm would start going up on its own until I have to turn it down. Can there be problem with my throttle wiring or need adjusting ?

Going into neutral is when the interrupter is used. The Alpha drive cannot be put into neutral when boat is in the water without it. If the switch hangs it will kill the motor

 

[Scott06]

Going into neutral is when the interrupter is used. The Alpha drive cannot be put into neutral when boat is in the water without it. If the switch hangs it will kill the motor

this …either switch is misadjusted or lower shift cable needs replacement. As the cable wears it take more force to shift and it can trip the shift interrupt. Disconnect lower shift cable from shift plate should shift easily by two finger grip. If not pull drive and diagnose

 

[rsxracing]

Yea after successful good star. Came back to the boat and having trouble starting it again. Not sure what to replace first and try first. Carb or plugs

 

[alldodge]

With it be hit or miss it;s most likely electrical.
Which means your back with the distributor or shift interrupter