1988 Force 125: Carb rebuild and timing set needed?

[ahickman]

Just got back from putting my new (to me) 88 Capri with Force 125 on the river. Had a difficult time starting/idling at the ramp, but got it running and moved up the river about a half mile at 2/3 throttle. Checked to ensure the new water pump was pushing water out the nostrils and was pleased. 20 seconds later, the overheat buzzer went off so I shut it down immediately and removed the cover. Engine/head was not so hot that I could not hold my hand on it. While I had the cover off, my buddy twiddled with the throttle linkage in an effort to bump the idle up a bit since it was having a hard time idling and moving into gear. He also twiddle with the timing screw just under the flywheel. We decided to give the engine a whirl in order to get us back to the dock. From there on out, it ran like crap and could never get it from neutral to forward gear. Just died out and ran like crap.

As I said, I just bought the boat and only changed out the water pump and did compression tests. ~130 psi on all four cylinders. Ran and idle OK in a barrel. Drained all the fuel I could since I didn't know how long it sat. Fresh mixture of 50:1 fuel/oil. Never opened up the carbs or the fuel pump. Did open up and test the thermostat. Worked well in a boiling pot of water. Crusty, but worked.

I really need some guidance on the following:

1. How do I go about setting the timing? Considerable experience on setting timing on Toyota 22RE engines, but none on this boat engine.

2. What is involved in rebuilding/cleaning the carbs? I am good with fuel injection, but know little about carbs.

3. Fuel pump??? When I pump up the buld, it gets good and hard. Fuel spits out of the carbs, so I assume the FP is good to go? Should I just go forward and get the new gasket kit?

Please help!!! I got a great 10 minutes running this boat and am so bummed to have it die on me on the first run...

Thanks,

Aaron

 

[Jiggz]

Re: 1988 Force 125: Carb rebuild and timing set needed?

This is the basic instruction for setting timing (static).

1. Remove spark plugs from the engine. Others also disconnect the fuel lines or remove the carb bowls to prevent fuel mix getting into the cylinders. Just make sure you do the timing in a very short time due to lack of lubrication into the cylinders.
2. Connect a spark tester or spark board to all spark plug wires. This will
prevent the outboard from starting during the test. The purpose is to ground the wires to prevent damages to the CD packs.
3. Remove the propeller.
4. Attach a timing light to the number one cylinder.
5. Shift engine into forward gear then to the wide-open throttle position. You are basically setting timing for WOT speed.
6. Crank engine over while aiming the timing light at the timing marks and
note the reading. Usually requires two people to do this depending if you have a remote starter or not. Make sure you stand clear off the engine rear.
7. The timing should be within the specifications given in the "Tune-Up
Specifications" chart.
8. Make any necessary timing changes by adjusting the timing rod connected
to the trigger housing. For your engine the max static timing is 34 BTDC although other manuals state 32 BTDC. Mine is set at 32 BTDC and running and performing well.
9. If necessary repeat the max timing procedure until the settings are correct

These photos show the timing rod, marks and also the stationary notch.

 

[ahickman]

Re: 1988 Force 125: Carb rebuild and timing set needed?

Thank you!

 

[Jiggz]

Re: 1988 Force 125: Carb rebuild and timing set needed?

As for the carb cleaning, you can do the basic cleaning which is to remove the bowls and then check the operation of the float and the needle valve. Usually, the problem is a sticky needle valve which prevents fuel from entering the bowl. I clean the ports shooting it with brake cleaners although others uses WD 40 or even carb cleaner.

With the bowl off, you can also clean the main jets. Additionally, remove the air screw (air-fuel mixture screw) and check for damages. I clean the port the same way by shooting brake cleaner. Re-install the air screw until lightly seated (do not force or tighten or it will be damaged) and then loosen up CCW 1 1/4 full turn from lightly seated. This is just the initial setting until you set your idle and usually you end up with just 1 full turn from lightly seated.

Before re-installing the bowls, check the floats for holes and proper operation. The needle valve should close when the float is in perfect horizontal position and opens when in the down position. If you have a gasket kit you should at least replace the fiber gasket on the bowls which tends to leak overtime. If you dismounted the entire carbs then you will need to replace the mounting gaskets.

 

[emoney]

Re: 1988 Force 125: Carb rebuild and timing set needed?

You should probably get a digital thermometer and get a real temp reading after you get it running correctly. Could be a bad alarm, but probably not an area to "assume" in. There are water passages that can get clogged up as well. A service manual is a great investment.

Pulling the bowl off the carbs will give you a solid idea if they are in need of cleaning. At least that's one way to tell. Little varnish in the bowl usually means a little gunk in the jets, etc.

 

[Jiggz]

Re: 1988 Force 125: Carb rebuild and timing set needed?

As for the fuel pump. The best thing you can invest before tackling this part is to install a glass or see through fuel filter. There is already an excellent filter built into the fuel pump but the purpose of the see through is just that to see if there is fuel pumping from the fuel pump when the engine is running. Although you can probably check fuel by disconnecting the fuel hose connection from the carbs. But the see through fuel filter provides a quick diagnostic tool without having to disconnect anything. Besides they are really cheap. I got one with a 1/4 connections which was perfect for the 125HP Force for less less than $10.

When priming with the primer bulb, when it gets hard it means the floats in the carbs and the needle valves are working. It doesn't necessarily indicate the fuel pump is working though. The only way to see if the fuel pump is working is when the engine is cranking over or running and see fuel coming out of the fuel pump which you should see if you have a see through fuel filter.

If you do not see fuel pumping into the see through filter while cranking or engine running, then check the fuel lines all the way back to the pick up tube. If the primer bulb collapses with no fuel pumping, it's either you have a stuck check valve in the bulb or a clogged pick up tube or blocked tank vent.

If the bulb doesn't collapse with no fuel pumping you either have a defective fuel pump or leaks on the suction side of the fuel hoses.

 

[ahickman]

Re: 1988 Force 125: Carb rebuild and timing set needed?

Updates:

1. Removed the over-temperature sensor from the head and tested it in pot of heated water. Went from infinite resistance to a few ohms just prior to water boiling.

2. Pulled the carb bowls, floats and air/fuel mixture needle. Full of fuel and no signs of water. Cleaned all with WD40 and then carb/choke cleaner. Needles looked good, no scoring or buildup. What I did find was that the top float was damaged. A large chip/section was missing. The previous owner must have cleaned out the bowl and pieces of float since there was none present in the bowl. Picture below of the damaged float. I did check that both floats were opening/closing the jet by squeezing on the bulb and raising the float to horizontal position. Fuel stopped flowing out of carb when they reached horizontal position. Assume they are working well enough.

View attachment 164257

3. Removed the fuel pump and split it open to look at the diaphragm and the filter. Filter was clean and diaphragm was intact. It looked a little stretched, but was still flexible.

4. Was able to remove all but one bolt on the exhaust plate. Hitting it with PBlaster tonight and will give it a tug in the AM. Should I expect the gasket to tear/break or is it pretty durable?

 

[Jiggz]

Re: 1988 Force 125: Carb rebuild and timing set needed?

The gasket should be intact unless it was glued during installation.

 

[ahickman]

Re: 1988 Force 125: Carb rebuild and timing set needed?

Jiggz, a couple more Q's:

1. Is there a method to easily removing the propeller?
2. What do you think about that damaged float? I have read where the white replacement float is problematic.
3. Can I just ground out the pugs using a wire bonded to chassis/ground? I don't have a spark tester or spark board. Not sure that I have ever seen either really.

 

[jerryjerry05]

Re: 1988 Force 125: Carb rebuild and timing set needed?




This is what I use to ground out the plugs.
Your pic of the float didn't open.
If it's a black float? I guess it's some kind of styrofoam??
It should be ok if too much isin't gone.
The white float is JUNK,no adjustment,don't buy or try to use!!

Removing the prop,this works on the worst stuck props.
I use the biggest 3 jaw puller,remove the arms and replace with 3 pieces of chain 16-18" long
Gonna need 3 bolts,6 washers and 3 nuts.
Wrap the chain around the ears,secure with the bolts and tighten down on the center bolt.
It should come off.
On real severe cases you might pull the prop off of the hub.
If that's the case you'll need to cut off the hub and the splined part.
Don't use heat as you'll ruin the seals on the prop shaft.

 

[ahickman]

Re: 1988 Force 125: Carb rebuild and timing set needed?

Jerry, I am going to put the damaged float back in as is since it seemed to float well enough in the bowl full of fuel. Going to look at a replacement on ebay also. Thanks for the suggestion on the puller. I assume the picture above is just for reference since it involves the flywheel rather than the prop. Is the center bolt usually a bear to loosen? Do I need to put it in gear before wrenching on it?

 

[Jiggz]

Re: 1988 Force 125: Carb rebuild and timing set needed?

When I remove my propeller, I use a 2 X 4 wood against the cavitation plate to prevent if from spinning. Drench it with penetrating oil and then use an impact wrench to remove the nut. Since I do annual maintenance of greasing the splines, it readily slides out. However, on my first try when I first had the boat, I had to use a mallet and a wooden block to hit it back. The chain method as described will also work. I've used the same technique when removing propellers from ventilation fans onboard ships during my navy years. And we're talking propellers at least 40" in diameter.

 

[ahickman]

Re: 1988 Force 125: Carb rebuild and timing set needed?

Got the carbs back together and the exhaust plate back on this evening. Put the prop in the tank of water and fired it up. Ran with a fast idle, but sounded solid. Didn't run it long at all. Waiting until tomorrow evening to try synching the carbs, set the timing and adjust the air/fuel mixture. Just need to get the prop off. Soaking it in PBlaster and will hit it tomorrow evening to see if it budges.

Jiggz, from you input, the order in which I should adjust is as follows, correct?

1. synch carbs
2. set timing
3. adjust air/fuel screw

I don't have a tachometer on this boat. Suggestions on what I could use for RPM measurement?

 

[Jiggz]

Re: 1988 Force 125: Carb rebuild and timing set needed?

Set the timing first since this does not require any fuel or the engine running to set it. Then followed by synching the carbs and adjusting the idle with idle screw and air screw. You might want to install a tachometer. I have one on the dash and also a tiny tach kinda thing inside the cowling.
For dash tach I recommend this: http://greatlakesskipper.com/product/56_76_80-boat-gauges-outboard-only-tachs/13801-tg-faria-faria-tc9781b-us-marine-6000-rpm-outboard-boat-tachometer-gauge.html

For the tiny tach version I used this: http://www.ebay.com/itm/Tachometer-Hour-meter-2-4-Stroke-Small-Engine-Spark-utv-atv-kawasaki-mule-teryx-/221098522611?pt=Motors_Car_Truck_Parts_Accessories&hash=item337a7fb7f3&vxp=mtr#ht_1805wt_1395

The only problem with the little digital tach is you need to select "1" which sets the tach to read 2 sparks per revolution. The instruction that came with it says to set it to "2" for two strokes and "3" for four strokes. But with a setting of "2" it reads twice as many RPM and come to find out the proper setting is "1".

 

[jerryjerry05]

Re: 1988 Force 125: Carb rebuild and timing set needed?

Yup just for illistration!!
If it spinning put it in gear or use the block.
I found it really doesn't matter,it comes right off.
I don't like to use too much PB or WD on the prop when removing.
It can actually lube the hub enough to let it come apart.
If the splines are really stuck they can hold the hub in place and then a rebuild is in order.
PB works too good in some cases.

If the props really sticky,I use a small propane torch on the very end of the shaft.
Sometimes it heats it just enough to loosen the frozen grease/antisieze.
Remember too much heat and you'll be resealing.

 

[ahickman]

Re: 1988 Force 125: Carb rebuild and timing set needed?

Gonna try the tiny tach version you recommended from ebay first. I have seen the tiny-tach recommend in many applications as an inexpensive tool. Just trying to spend as little as possible on this project until I feel it is worthy of investing. The quick run I had the other day on the river tells me the engine is still strong, but needs some TLC. Going out now before leaving for work to see if the prop nut will spin off easily.

 

[ahickman]

Re: 1988 Force 125: Carb rebuild and timing set needed?

Just finished setting the timing. Put it dead in the middle (center of three marks). This is 32 BTDC, correct?

 

[Jiggz]

Re: 1988 Force 125: Carb rebuild and timing set needed?

Not sure who and where your marks are. But it's really easy to find out. Count the number of gear teeth on the flywheel and then divide 360 by this number (of gear teeth) and that will give you degrees per gear tooth. From the TDC mark you can count the number of gear teeth to come up with 32 degrees. For example, my flywheel has 107 gear teeth. Dividing 360 by 107 gives 3.36 degrees per tooth. To set 32 degree advance, divide 32 by 3.36 which is around 9.5 teeth. Meaning the 32 degrees is between the 9th and 10th gear teeth from TDC mark. On my flywheel there are three marks. The first one is the TDC which is a single vertical line. Then there are two other marks left of the TDC mark which are supposed to be 30 and 34 degree marks.

 

[jerryjerry05]

Re: 1988 Force 125: Carb rebuild and timing set needed?

[Jiggz what motor do you have?
The 3 marks I believe are 32 30 28
The single line is for finding TDC or checking if the key is sheared.
I posted at the top of the forum the flywheel info for most Forces.






ATTACH=CONFIG]164523[/ATTACH]

 

[Jiggz]

Re: 1988 Force 125: Carb rebuild and timing set needed?

Jerry, you are correct after verifying with the Clymer's manual the three marks are 28, 30 & 32. My digital manual however recommend setting the static timing to 34 which made me assume the highest mark must be 34.