trouble starting 1975 evinrude 135hp

D

depps

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Dec 26, 2007
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i'm having trouble starting 1975 evinrude 135 hp outboard when cold. The last 6 starts have taken anywhere between 30 secs and 30mins. Once the motor starts it runs fine and will restart easily. I used the boat for about 4 hours 2 weeks ago however couldn't get it started today. The starter motor seems to be working fine, the motor turns over but just won't start. The spark plugs were replaced about 5 weeks ago, the fuel/oil is good, the primer bulb fills ok, the battery is 6 months old and fully charged. Is it likely that i'm just flooding it and if so whats the best way to clear the excess fuel? or is there some other problem.

My normal starting procedure is to fill the primer bulb, put the warm up throttle leaver on full, and turn the key with the choke on.

I also noticed a few drops of fuel leaking from a T junction after the fuel filter but this only occurred when i got frustrated and squeezed the primer bulb a few too many times.

thanks
Matt
 
F

F_R

Supreme Mariner
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Jul 7, 2006
Messages
28,195
Re: trouble starting 1975 evinrude 135hp

Two things:
Take a spark checker along next time and when it won't start, check the spark with the plugs in. If no spark, remove the spark plugs and recheck for spark. If it sparks with plugs out, but not in, either it is cranking too slow or you have stator issues.

Next time it won't cold-start, try choking it with the manual choke lever on the carbs. If it fires right up, you have an electric choke issue. It could be out of adjustment, spring broken, or electrical trouble. Concerning the electrical part, there is a service bulletin about re-wiring the choke.
 
HighTrim

HighTrim

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Re: trouble starting 1975 evinrude 135hp

Loosen the carb choke rod fastener lock screws. Place the manual choke lever in the choke "ON" position. Manually close the other choke valves and tighten the screws. You can also adjust the choke solenoid, just close the choke valves with the manual choke lever. Loosen the clamp screws that are on the solenoid and hold the plunger to the bottom of the solenoid and slide assembly aft to remove the slack in the linkage between the plunger and the choke lever. Move the solenoid (only) aft .016 of an inch and tighten the clamp screws

FR concerning the service bulletin, was it for warm start up?

The one I know of from this forum, I forget who the original author was, yet it concerns the purple/white and purple/yellow wires coming from the choke solenoid. Following those wires to the terminal strip, you remove the purple/yellow wire coming from the solenoid from it's screw terminal. Leave the other purple/yellow one where it is. It will no longer be connected to anything. Then you connect the wire that you just removed to the screw where the purple/white wires are connected. That will make 3 wires under that screw...two purple/white and one purple/yellow.

When wired this way, you will get full choke when you operate the switch at the control, and none when you let off the switch. In other words, you have full control over the choke operation. You may have to "bump" the switch a few times to keep it running on a cold startup.

However I was told to reconsider doing this. The original setup provided for an automatic partial choke during warmup. The reason for modifying it is to prevent choking when you don't want it....in warm/hot weather. The warmup feature is nice in cold weather. It all depends on whether you are having warm-start stalling problems from over choking.
 
C

CharlieB

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Apr 10, 2007
Messages
5,617
Re: trouble starting 1975 evinrude 135hp

First, pull your spark plugs to look and see if they are carbon fouled and needing replacement.

While they are out it is a good time to

A Check spark to be sure that you do not have an electrical problem in the ignition making it hard to start.

B Check compression to ensure that your engine is in sound mechanical condition.

If both test A & B pass then it is time to move on to the fuel system.

You may have a problem with the enrichener/choke not functioning, making it very difficult to start cold.

Test by disconnecting on of the small fuel lines between the enrichener and a carb, pump up the primer bulb then have a helper turn on the key and press the choke. You do not have to actually crank the engine.

Hopefully the small amount of fuel pressure in the line was enough that when the enrichener was activated by the choke switch you saw fuel stream from the small hose you disconnected, if noty then pump the primer bulb while your helper presses the choke switch. If still no fuel the the enrichener is cloged or the coil is burnt out and may need replacement. Verify that 12 volts is being delivered to the enrichener with a test light to rule out an electrical supply problem BEFORE you order a new enrichener.

If fuel DID come out then you just proved that it is NOT a choke problem and you may have to dig deeper into the fuel system, like checking the carb bowls for water or gunk.

Try these things first then repost with your results.
 
72SideWinderSS

72SideWinderSS

Petty Officer 1st Class
Joined
Jul 8, 2006
Messages
268
Re: trouble starting 1975 evinrude 135hp

A 1975 Evinrude 135hp has butter-fly Chokes.
Majority of cold start problems are usually attributed to the butter-flies not closing completely while cranking.
Try checking/adjusting the the chokes.
 
E

ezeke

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Sep 19, 2003
Messages
12,532
Re: trouble starting 1975 evinrude 135hp

The choke plates are probably not closing fully while cranking, which can only be determined by watching them with the air silencer cover off while someone else cranks the engine.

The plates need to stay 100% closed while the engine is cranked, and able to offset the vacuum created by the pistons.

If the choke plates are synchronized, you need only to loosen and move the actual choke solenoid in small increments to adjust.

The likelihood of flooding the cold engine while cranking with the choke plates closed is small.

You don't have the "enrichener" mentioned unless new carbs were added years after your motor was built.

BTW, try not to squeeze the primer bulb too hard; you can rupture the fuel pump.
 
E

ezeke

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12,532
Re: trouble starting 1975 evinrude 135hp

Concerning the aforementioned rewiring of the choke solenoid, most of the 1975 V4 engines came without the switch or were changed by service departments. The Service Bulletin came out in February 1974.

It may still be wired to a temperature switch, however. If so, there will be a wire and switch mounted at the lifting eye and connected to the terminal block.

Concerning the fuel leak at the "T", if fuel can get out, air can enter. You may want to get some new clamps.
 
F

F_R

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28,195
Re: trouble starting 1975 evinrude 135hp

Yes, the warm-up switch modification was to prevent over-choking a warm motor. However, if it is connected in that fashion, and the thermal switch is bad, you will only get the solenoid input on the purple/white wire. You need solenoid input on both purple/white and purple/yellow to get complete choke closure for cold starting. Doing the rewire modification assures that this happens, even if the thermal switch is kaput.
 
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