1967 60 hp seahorse v4 vxl-13 low rpms

[Compaqp1]

So I got a great deal on this old 71 Invader or so I thought. Took it home and then put her in the water. Well she would start but wouldn't do anything but troll even at full throttle. Asked around and was advised to buy a manual and go over the sync procedure. Did that, also dismantled the carb and cleaned everything out. Took my needles to a local daeler that's been around for a long time and they said they looked fine. Put it all back together along with a new fuel pump diaphram. Things got better but not great. The engine will only rev to about 2300 rpm per my OMC tach set on 6, just barely enough to get that old fiberglass tri-hull to plane and then run at about 27.5 mph per the GPS. After about 2-3 minutes of finally scooting across the water it bogs down and only runs at idle even when set at full throttle. Back the throttle down all the way and sometimes it dies but will usually idle. Let it idle for about 1-2 minutes and it will get up and go again only to repeat the cycle. It's also really hard on fuel consumption. It will suck down 5 gallons just to go about 5 miles. I know this engine is a gas hog but is it this thirsty? I believe my manual says it should tach at about 4500. Any thoughts on what's keeping my rpm's down and what is causing it to bog down would be great. I've done too much to this boat motor and trailer just to give up.

 

[HighTrim]

Re: 1967 60 hp seahorse v4 vxl-13 low rpms

YOu should start with the basics and do a spark and compression test then let us know the results. The compression test can be done with a cheap screw in compression tester available at any parts store

(Compression & Spark Test)
(J. Reeves)

1st - Regardless of what problem one might encounter, always start with the basic troubleshooting procedure. Check the compression which should be in the range of 100+ psi (somewhat less on the smaller hp engines) and even on all cylinders.

2nd - With the spark plugs removed, rig up some type of spark tester whereas you can set a gap to be jumped. On magneto ignition systems.... and also the Battery Capacitance Ignition system OMC engines from 1968 to 1972, set the gap to 1/4". On the solid state OMC ignition systems from 1973 to the present, set the gap to 7/16". The spark should jump the gap with a strong blue lightning like flame..... a real strong blue snap!

If there was no spark, on engines from 1973 up, disconnect the RED main electrical plug at the engine. Remove the s/plugs. crank the engine via the starter solenoid (jumper bat term to small 3/8" term nut, not the ground nut) and observe spark. If spark is now okay as stated above, the usual cause is a shorted ignition switch.

If the above checks out as it should, and the engine dies out when throttle is applied or won't idle, it is usually due to one or both of two things. The carburetors are fouled, in which case the cure would be to remove, clean, and rebuild them..... or the timer base under the flywheel is sticking which would result in a retarded spark. If the engine will not fire/start at all even though you have the proper spark and compression, it's usually due to fouled carburetors.

To check the timer base for sticking (Engine Not Running), spin the prop to align the shifter dog with forward gear and while doing so, put the engine into forward gear. Now, while watching the timer base, slowly apply throttle clear up to full throttle. The timer base should move smoothly all the way up against the black rubber cap that is atached to the end of the full advance spark setting screw. If the timer base sticks, find out why and correct that problem.

Usually any sticking of the timer base is caused by one of the four retaining clamps being slightly too tight. Putting a very thin washer under the clamp cures that problem. Some boaters use a thin screwdriver to bend the clamp upwards slightly but I prefer the thin washer. The sticking can also be caused by having a faulty stator start to melt down, resulting in a sticky substance dripping down on the timer base nylon retaining ring.

 

[Compaqp1]

Re: 1967 60 hp seahorse v4 vxl-13 low rpms

I guess I forgot to mention my comp is good, seems like it was between 112-117 well in the 10% range between cylinders. I do have good spark, the original plugs Champion J4J were unavailable so I tried to run a Champion J4C and the engine wouldn't run on them so I went with an Autolite 294. The timer base apears to be functioning properly. I did notice some of what appeared to be the clear winding wire coating that goes in a coiled wire assembly. Is it possible my coil may be in the beginning phase of breaking down, loosing high energy spark when it gets hot and regaining it's spark when it cools when I let it idle? I'm kind of new to marine engines but they don't appear to be much different from any other engine. This is just driving me crazy that I can't figure it out.

 

[Compaqp1]

Re: 1967 60 hp seahorse v4 vxl-13 low rpms

Compression #1-126, #2-118, #3-112, #4-115. Spark jumps up to 3/8" (actual spark tester) and it gets intermittent after that (magnetto ignition). I tore down the top part of the carb as much as I could with it on the engine and I noticed it has a sealed cork/wood float and there are dark brown patches on it. The carb has fixed high speed and low speed adjustable. Anyone know where I can find a rebuild kit for a carb this old.

 

[F_R]

Re: 1967 60 hp seahorse v4 vxl-13 low rpms

Cleaned the carb, you say. Did you take out and clean the high speed orfice plugs? They must be absolutely clean, no compromising allowed.

Good spark? How good? Will it jump a 1/4" gap?

Running at partial speed/rpm is almost always because it is not running on all cylinders. Your compression is good, which leaves ignition and carburetion. One set of points fires two cylinders, and one side of the carburetor supplies two cylinders. Revisit your previous work with the above questions in mind.

A sneaky problem on those is the distributor rotor. They arc through to the shaft through a microscopic pin hole burn-through.

Edit: We were both typing at the same time.

 

[Compaqp1]

Re: 1967 60 hp seahorse v4 vxl-13 low rpms

I removed the high speed orifices toady and noticed some very very minor stuff on the inside of them, almost slipped by me, it's so minor. Guess I'll clean them just in case. I'll be unable to work on it for about 1 week now so I'll keep you posted on what I find with the distributor. It's been 2 years since I worked on this but everything looked O.K. then. The stuff I have listed in the previous posts is what I've done today. This can't be as difficult to fix as it seems. Would any of this cause it to bog down after it's been running for a while and then run fine (as good as it will, 2300rpm) when it sets and idles for a few minutes or would that be another issue? If I can find a rebuild kit with a float I would prefer to rebuild it.

 

[Compaqp1]

Re: 1967 60 hp seahorse v4 vxl-13 low rpms

Ok, looks like I was wrong on the ignition. It has a battery ignition. I read something about a rsister wire controling the current flowing to the coil. Could my problem with the bogging down be in the wire? I tore down the carb and blew everything out and didn't find any clogged or partially clogged passages. I'm going to go over the synch one more time and see what happens. How can I tell if I'm overheating with this engine and if it is getting too hot would this cause it to bog down kind of like a vapor lock on a 4-cycle? I've got about $500 in this boat now and it's about time it runs right.

 

[F_R]

Re: 1967 60 hp seahorse v4 vxl-13 low rpms

Do you have the original factory-supplied wiring harness going to the front of the boat? The resistor wire is built into that cable. It is the red and white wire. The cable must not be shortened. Nor should it be substituted by a cobbled wiring job without a resistor.

Not having a resistor (substituting a plain wire or shortening the resistance wire) can overheat the coil and cause ignition problems, or even damage the coil. If the resistance wire is bad, it just won't run at all. That's the easy one.

Did you consider the rotor yet?

Engine overheat certainly can cause slowing down, but by impending siezure, not vapor lock normally.

 

[Compaqp1]

Re: 1967 60 hp seahorse v4 vxl-13 low rpms

New question. I was looking my wiring over and comparing it to the diagrams in my Seloc book an low and behold I found a problem or so I thought. In saection 5-32 it has a schematic showing the resistor wire connecting to the pos side of the coil but when I look in the back of the book at the diagram for the 67 60hp v-4 it shows the resistor wire going to the neg terminal of the coil. I had it hooked up to the neg terminal and it would make sence that that would be wrong since I run just fine for a few minutes and then start to lose power (droppong voltage from the coil due to backwards polarity?). I have my tach wire connected to the neg terminal with my resistor wire just like the schematic in the back of the book shows. My question is which diagram is correct and where should my tach wire connect?

 

[Compaqp1]

Re: 1967 60 hp seahorse v4 vxl-13 low rpms

Yes I do have the original harness with the resistor wire and yes it is attached.

 

[F_R]

Re: 1967 60 hp seahorse v4 vxl-13 low rpms

Risistance wire goes to + side of coil. Points and tach go to - side.

 

[Compaqp1]

Re: 1967 60 hp seahorse v4 vxl-13 low rpms

The problem still exists. On my tach it has a dial that has 2, 3, 4, 6, H on it. It was originally set on 6 and I backed it down to 4. Where should it be set for a V4? Tore the carb down and cleaned and blew everything out, carefully checked wiring and that the engine is in synch. Pulled the hood off at night and didn't see any spark leakage. The only thing I haven't done is change the rotor but how would that have the effect of running fine for a while then bogging down for a few minutes only to run fine again after letting it idle. Would a bad coil or condenser have this affect? Noticed today that my transom is getting pretty bad, it's flexing to the point that when my manual trim is set at it's highest setting, the cavitation plate still doesn't plane in with the hull making it almost impossible for the boat to plane. Someone has to set up on the bow for it to level out. Won't plane until I get up to 15mph. Is there a quick for a bad transom? I couldn't think of one that would hold up and I worked for OMC in Lebanon Mo at the Lowe factory for 3 years so I know quite a bit about boat fabrication but that's with aluminum not fiberglass. I worked there when Green Marine bought them just before they went hull up (I know, lame humor).

 

[Compaqp1]

Re: 1967 60 hp seahorse v4 vxl-13 low rpms

Replaced the coil and resister wire with an auto coil and ballast resister and seems to have solved the problem with bogging down. Boat seems to plane faster but I'm still not sure about my rpms or even if my tach is set correctly. I did change the setting to 4 and now the tach shows about 4000 rpm's at full throttle in the water. Boat does about 27 mph with the 60hp engine. This boat is built for up to a 90 horse but the transom couldn't handle a 90 now.