470 poor starting after rebuild

Rake722

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Apr 23, 2012
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Timing is done and she finds nicely.

ill have to get testing with the multimeter next time I’m at the yard and see if that starter is the issue. I think you are right because after say 5 decent cranks it slows right down to barely cranking at all. Leave it for 5-10 mins and back to cranking 5 times before slowing down.

video of her running after timing being set

https://youtu.be/anfpFxzaGAo
 

Rake722

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Apr 23, 2012
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Look for voltage drops between the battery and the starter, and don't for get the negative side...

Put the positive lead of the multimeter on the battery positive post, and the multimeter negative lead on the starter post. Crank the engine. Do the same on the negative side, one lead on the negative battery post (not the terminal, the actual post) and the other lead on the starter case... You need to see a combined voltage drop less than 1/2v .

If everything is ok, then the starter is suspect.

Chris......

update - did the test above and on the positive side the voltage drops from 12.5 to 2v while cranking.

negative side also 2v

wjere should I be looking next ?

thanks
 

Rake722

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Even hooked up my trucks battery via jump lead and cranking becomes slow and laboured after 5 or 6 rotations.

battery has 13.3v
 

Scott06

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Did you verify the positive and negative battery cable condition? Good clean tight connections with no corrosion at either end? Connection between the end where it's crimped on the cable may be corroded
 

Rake722

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A bit more info on the ignition side - I jumpered from better positive to coil positive and the voltage drops from 11.5 to 9 v when cranking.

is that about right too ?
 

Rake722

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Did you verify the positive and negative battery cable condition? Good clean tight connections with no corrosion at either end? Connection between the end where it's crimped on the cable may be corroded

hey Scott many thanks for the response. I was doing this in 40mph wind so did not do tests between post and terminals but all the terminals are new and free of corrosion.

to be clear about the rest, when I connected the meter to the positive post and positive starter post I got 12.5v that dropped to 2 volts while cranking.

on the negative side I got 0 volts when connected and 2 volts while cranking.
 

achris

More fish than mountain goat
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2 volts is too high. You have a bad/dirty connection somewhere.
 

Rake722

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2 volts is too high. You have a bad/dirty connection somewhere.

thanks chris, I’ll test from police post to each terminal in the circuit step by step.

i will go battery to terminal then positive stud on the solenoid then to the other large stud then yellow cable terminal on splendour then to terminal on starter stud.

does that sound about right ?
 

Rake722

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Apr 23, 2012
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Hmm another thought - could this be a bad earth ? The only earth is the negative lead from the battery to the starter neg post.
 

achris

More fish than mountain goat
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You're procedure sounds good, and you need to do it for both positive AND negative sides...
 

Rake722

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Ok been down to the boat and cleaned all connections related to the battery. Removed isolator and connected wires with a bolt.

volts from positive to starter now down from 12.5 to 0.6 when cranking.

from negative post on battery to starter I get 0v to 3v on cranking.

the motor doesn’t seem to labour like before but maybe I just haven’t cranked long enough.

seems like 0.6 is better than 2v befote
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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try a new cable

if any part of the cable is green, simply replace it.
 

Rake722

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Apr 23, 2012
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Whoever said that whenever they had dart issues they trouble shoot the spark - thank you. You helped me solve the issue my boat has had for years.

Yesterday I went to the boat and I removed all the spark plugs only to find that they’ve all had an orange spark. I did all the usual things such as checking the gap cleaning the plug eliminating the high tension leads to no avail and I then decided to change the flamethrower coil for the original coil I once used on the boat five years ago the result was an ice blue that spark .

Thinking that I have found the problem I excitedly got the hose out I’ve put the maths on and try to start the engine but no it’s still would not start so I checked that the fuel pump was pumping to feel to the carburettor but there was no fuel. After making sure that the tank had fuel in it I proceeded to prime of the fuel pump with a priming bulb after which the boat started first turn of the engine .

after this the boat started flawlessly every time I will go back and doublecheck that this is still the case as soon as it stops raining over here .

I also managed to get my temperature sensor and gauge working by connecting the tandem wire to the second prong of the sender .

Things seem to be looking up

https://youtu.be/QVYz4Zm4eF0
 

havoc_squad

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Mar 5, 2011
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Thinking that I have found the problem I excitedly got the hose out I’ve put the maths on and try to start the engine but no it’s still would not start so I checked that the fuel pump was pumping to feel to the carburettor but there was no fuel.

I didn't know the 470 engine took math to get started. Which type does it need, simple arithmetic, alegbra, trigonometry?

Also, where do you plug into the harness to send the values?

Looks like spelling autocorrect on tablet/phone is trolling people on a regular basis.
 

Rake722

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Apr 23, 2012
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Lol 😂 maths should have read Muffs. I guess we need an engineers glossary in autocorrect
 
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