test wheel

[ferdly1]

Is it necessary to have a test wheel to adjust timing. The reason I ask is a saw the video for adjusting timing on a 120 hp motor. However I have a 1997 40hp force 2 cylinder. It has good compression 120 on both cylinders. However it runs herky jerky when accelerating and idles ruff. Which leads to another questions. Engine smokes really bad. Sounds and looks like it is leaking exhaust thru the gasket between engine and adapter plate. Could this cause rough idle.

 

[Jiggz]

If you are planning on doing what is called a dynamic timing yes, you will either need a test wheel or the prop itself at WOT speed which is really almost impractical. So instead, you should just do static timing which does not even require running the motor but requires good cranking. If you read through the sticky posts on top of the forum, there is actually a link for a video to show you the step by step procedures to do a static timing.

If you have not messed with the flyhweel, trigger, stator or with the timing tower, timing usually stays put. Of course, it does not hurt to verify. Rough idling is not one of the symptom of bad timing unless it is way out of whack. Rough idling is usually connected to misfiring due to electrical problems, fuel related problems or fouled spark plugs or carbon build up.

You can a lot of info by reading the sticky posts in the forum starting with the "Link and Synch".

 

[pnwboat]

If the exhaust is indeed leaking at the adapter plate, the engine will suck the exhaust fumes and not run very well. You can double check by simply removing the engine cover and see if there is an improvement in the way the motor runs.

 

[ferdly1]

Thanks so very much for your input. I still have questions. I did see the video. However the procedure was for a 3-4-5 cylinder engine and mine is a 40 hp two cyl.. I am trying to relate to my engine so bear with me while i explain my understanding of the video. Basically You are setting the timing by not running the engine but by cranking the starter in gear and using a timing light attached to number one cylinder. You have to jumper the neutral switch so you get fire in gear. On my engine the switch is located in the control box. I guess i can use a wiring diagram to find wire coming from switch.

 

[Jiggz]

No Title

The static timing procedures are still the same with your 2 cyl motor. Yes, by cranking the engine without actually making it ran with the throttles in WOT position or the control lever in full fwd position, this simulates WOT speed without actually running at WOT speed. This is because the timing mechanism is purely mechanical (controlled by the carb linkages through the timing tower and the trigger advancing plate) and does not involve vacuum or any electronic sensing devices. And because of some slops, the static timing is set 2 degrees less than desired settings.

The jumper on the interlock switch is required to allow you to crank the motor while it is out of neutral. Typically, you can only crank the motor when in neutral. Here's a diagram that shows the hot wire (yel/red from the starter solenoid to the harness connector) that goes to the ignition switch. It does not show the interlock switch probably because as you mentioned is located in the control lever. If you cannot access the interlock switch, your best bet is to place the ignition switch in the "Run" position and use a remote starter to crank the engine

 

[ferdly1]

Thanks. This is the procedure i followed with my 40 housepower 2 cyl force. First i checked and adjusted wot throttle. Mine was off a little. With throttle pushed to wide open. The throttle plate in carburetor should be horizintal. Next I shorted number 2 coil. I just inserted a long bolt in sparkplug cap and tied a wire to it. I then grounded it to the battery. I did not ground the number one lead. Dont see how you get a sgnal if you groound it, I actually tried grounding it, no signal to timing light. I then removed plugs. Engine cranks much faster without compression. Hooked up timing light to number one lead. I hooked up my remote start switch to the starter relay where the yellow red wire from ignition switch hooks. I unhooked yellow red wire probably not necessary. I then pushed throlle all the way forward and turned ignition switch to run position. Pressed button on remote starter switch. Now starter should be spinning flywheel. You should be able to check and adjust timing. Although my timing was off, which i corrected. It did not solve my ruff idle problem. Gonna run engine tonight ot see if there is any crossfire. There is one thing I have noticed. Intake manifold has lots of moisture on outside. Especially after i go for a run. Not just moisture in has puddles of water. It isnt coming from engine. Saw this once on a car engine. But that was due to oversized carb on engine. this is just a single barrel carb on this 2 cylinder engine.

Thanks for the help guys

 

[Jiggz]

With your rough idling you need to verify if you have misfires or not. This can either be caused by electrical or fuel related problems. To check for misfires caused by electrical problems, you can use your timing light to check for consistency in sparks on each of the spark plug wires. Double check your spark plugs are not fouled to start with. If there is inconsistency you can switch electrical components around to see if the problem follows. If sparks are constant and consistent, then it could be a carb problem. Dismount the carb bowl and clean and inspect the float, needle and inlet ports.

 

[ferdly1]

i checked the carb and ran the engine last night didnt see any stray sparks. The plugs i am using are centerfire. They sure seem to run clean. Gonna pull head cant seem to find head gasket for this motor. 97force 40hp. One thing that really bothers me is all the moisture that forms on carb and manifold. Like its sucking to much air. I looked at reeds after removing carb. The right side looks flat the left side seems to be open a hair. The reed switches and gaskets are available. Oh other than timing not. sure what you meant about checking fire with timing light. I happen to have aanother stator cdm modules off of another 40 hp mercury. was gonna swap that over.

 

[Jiggz]

An inductive timing light that is connected to a plug wire will fire everytime there is a spark in the specific spark plug. It is the same way when you set or check your timing. However, you can also do the same for checking the consistency of sparks in any of the spark plugs by simply watching the strobe light from the timing light. Of course, you wouldn't want to look directly into this light since it is blinding (temporarily) so instead you use a dark colored paper to bounce the light off. The goal is to see if the sparks are consistent at different engine speeds. If it is not, then it tells you there is misfiring due to electrical problems.

Another way to test is to buy an in line spark tester which is basically the same except this one is inserted between the spark plug and the plug wire. Again, the goal is to see if there is constant and consistent sparks. If there is, on both spark plugs, then you can rule out electrical problems as source of your misfiring or rough idling. Then you can focus more on the mechanical side of the problem, which can be the carbs improperly settings, reeds, low compression, water intrusion, etc.

As for the head gasket there is a replacement non-oem available at iboats.com

Here's the link:

 

[ferdly1]

Thank you for sharing that with me. Never heard of using it that way. Always learning something new. However I think I found my problem. Looks like reed valves are bad. I have ordered new ones. That explains the extreme moisture on carburetor and

 

[Jiggz]

Leaky or bent reed valves will result in fuel being spit more out of the carb's mouth rather than moisture. Moisture build up on the intake is an indication of loose intake adapter or leaky gasket.

 

[ferdly1]

I replaced the reeds. Engine runs better. Still not as smooth as I would like. Still getting moisture on manifold. I replaced the reed gasket, however they were out of stock on manifold gasket and carb gasket. They are being ordered now. Another problem I am having is exhaust leaking into engine compartment. With hood on engine idle is weaker but doesn't stall out. There are 3 gaskets for the exhaust. Not sure which to replace or should I change all three. And thanks for all your help so far. I feel confident enough to take my brother fishing this weekend.

 

[Jiggz]

Leaky exhaust in the cowling will always result in poor performance starting from idling up to WOT. You need to identify where it is coming from, either from the exhaust plate or from the motor leg-Powerhead adapter plate. There is an ongoing thread about a 50 HP replacing his exhaust gaskets on the adapter plate. Go read through this is you think your leaky exhaust is coming from the adapter plate. There are two gaskets, upper and lower that needs to be replaced and should be replaced as a set everytime. With the exhaust cover or plate, there are also two gaskets, one for the plate and one for the cover. Again, these are replaced in sets.

 

[ferdly1]

Thanks! Thats just what I wanted to know. My clymer manual doesnt cover this.