Force 150 head gasket questions

[pnwboat]

Re: Force 150 head gasket questions

You're probably right in that they are trying to maximize the chances of success while minimizing their liability. It is important to double the oil to 25:1 ratio during break-in, and limit engine speed for the initial few hours. Also generously coat the whole piston and cylinder walls with 2-stroke oil when putting it together.

I've seen several motors with new Wiseco pistons where the owners have not followed any break-in procedure or only broke it in for 20 or 30 minutes and went to WOT only to find out that they wiped out the rings and pistons bad enough to have to replace them. I've also seen others where it did not do any harm at all...go figure. It seems that water cooled 2-stroke outboards can be less forgiving when it comes to breaking-in new pistons/rings as compared to automotive 4 stroke engines.

I would follow the break-in procedure as best I could to be safe.

 

[Jiggz]

Re: Force 150 head gasket questions

This is the break in schedule from the 85/125's Manual from Force.
1. Use 25:1 fuel/oil ratio during break in period
2. For the first 5-10 mins operate engine at a fast idle in gear (under 2500 RPM). Check operations of cooling system
3. For the remainder of first hour, do not operate engine over 3500 RPM or 1/2 throttle
4. For the second hour, run 3/4 throttle with occasional bursts to wide open throttle for up to one minute each
5. Avoid continuous full throttle operation for extended periods during the next four hours
6. Your outboard motor may now be operated at any throttle setting desired using the proper fuel ratio, 50:1

Note this is a total of 6 hour break in period using 25:1 ratio of fuel mix.

 

[HotTommy]

Next question

Next question

My new piston kit arrived and I was surprised to find it did not include any bearings. Should I automatically use new bearings for the piston pin and crankshaft, or is it more customary to reuse the old ones?

 

[pnwboat]

Re: Next question

Re: Next question

If you have the Wiseco forged pistons, they require a special set of wrist pin bearings P/N WP29-1. These bearings are slightly different than the original factory bearings.

As far as the bearings for the big end of the rod, if the original bearings are not pitted or blue from over-heating, it's fine to re-use them. Or you can order new ones. Your call on that one.

 

[HotTommy]

Re: Force 150 head gasket questions

OK. The crank bearings appeared to be in good shape, so I'll reuse them. The piston had a note in the box saying to use Wiseco # W5216 bearing kit. Thanks to you, I understand why. I've ordered the kit.

 

[HotTommy]

One step forward, one step back

One step forward, one step back

Following a week off for spring break and waiting for the last parts to arrive, I started the task of installing the new piston today. What follows is intended more as consolation for other novices who may find this thread and try this job themselves. It is not advice from an experienced outboard repair man who knows what he is doing.

My first job was to prepare the new piston for assembly. Everything was new except the connecting rod. A helpful youtube video by an Australian outboard mechanic showed how easy it is to install the connecting rod and bearings into the piston. It?s a simple matter to remove the spring clips from each side of the rod pin and slide it out of the old piston ?.. that is, it would be easy if the factory rod pin were held in by spring clips. Mine was pressed into the piston by some large automated machine. Thus, I had to fabricate a saddle to hold the piston while I pressed/hammered the pin out. I have a large vice that could not budge the pin, and my BF hammer did no better. So I broke out the torch and heated the piston (being careful to stay well clear of the connecting rod). With the help of a long breaker bar on the vice and some old, well used curse words, the pin came out. Fortunately, I wasn?t concerned about any of the old stuff except the connecting rod.

Assembling the piston/connecting rod/pin/bearings was as easy as the aforementioned video indicated ?. until I tried to install the first retaining spring clip. The guy in the video either has fingers of steel or was using a spring clip that had been reused so many times it had lost some of its tension. Regardless, I wrestled with mine for a while, walking that fine line between forcing it in with large, hard tools and damaging the sides of the piston. I finally got both clips in and prepared to face the engine.

I won?t go into all the steps and missteps in my first two tries to install the piston/connecting rod/bearings. But here are the major lessons learned.
1. It was a good idea to drape a large white old T-shirt on the engine just below the reed valve window. It caught everything I dropped, and the pieces are much easier to see on that cloth than in the dark, greasy recesses of the engine cowl.
2. It is not a good idea to remember which way the connecting rod cap goes on the rod when you know that your memory is not that good anymore. Next time, write it down somewhere..
3. It is easy to put bearings and the cage on the side of the crank that always faces outward. It is not so easy to do the other side. Sliding bearings between the crank and the connecting rod is not that easy as the connecting rod is free to wallow back and forth until everything is just about in place.

Running out of time and patience after two failed efforts, I decided to start anew tomorrow. As with most jobs, I get better with each attempt and as long as I don?t lose or break something, its only cost me some time. Hopefully, I?ll be writing about my successful install tomorrow.

 

[Jiggz]

Re: Force 150 head gasket questions

As mentioned mentioned before, use an alignment tool for the caps to ride on the crank, i.e. 1/8" wire. It will make your installation a lot easier.

 

[HotTommy]

Re: Force 150 head gasket questions

As mentioned mentioned before, use an alignment tool for the caps to ride on the crank, i.e. 1/8" wire. It will make your installation a lot easier.

I did that. It may have helped, but not enough to compensate for my lack of experience.

 

[pnwboat]

Re: Force 150 head gasket questions

Just be careful and a little patience...actually a lot of patience...and you'll eventually get it. You got the old piston off the rod. That's usually the show stopper for most folks.

 

[HotTommy]

Success!

Success!

The piston assembly is in! .... While reviewing the lessons learned from yesterday's two failed attempts, two insights came to me. First, we can only see the outward facing side of the crank when looking at it through the nearest hole (cylinder or reed). The only time we can see the inward facing side of the crank clearly is when it is nearest the reed side while we look through the cylinder. Second, I noticed that while disassembling some of yesterday's work, one of the bearing cages fell out on to my catch cloth with all its bearings securely held in place by the Vaseline I was using as gel/lubricant. Armed with those insights I developed what will be forever known and revered here as the HotTommy method of piston assembly.

My method differs from those described previously by swapping the easy connecting rod fitting but tricky bearing insertion technique for an easy bearing insertion but tricky connecting rod fitting technique. Specifically I made a tool out of 1" x 10" sheet of very thin flashing aluminum. (Think of a long, thin putty knife.) I lathered up a cage filled with bearings and placed it on the end of the aluminum. With the crank near the reed side, I slid the cage in through the cylinder and pressed it against the inward facing side of the crank with a long rod. I then rotated the crank to the cylinder side and slid the second cage into place. That left two bearings to insert where the cages meet. I used Vaseline to hold each on the end of the rod while I maneuvered it into place. Working through the cylinder hole is much easier than the reed hole.

With the bearings in place I rotated the crank back near the reed hole and maneuvered the rod cap into position. I then positioned the crank to the right side of the reed hole so I could insert the long guide pin through the left hole in the rod cap. I then inserted the piston assembly into the cylinder starting with the guide pin going into the hole in the rod. As the piston neared the bottom of the cylinder, I checked alignment of the rod with the cap and maneuvered the crank slightly to help them align. When the rod was close enough, I started the first cap bolt and tightened it until it was just snug. I then rotated the crank just enough to do the same with the second cap bolt. With both snugged up, I rotated the crank a couple of times to check for binding or unusual noises. I couldn't find my Loctite, so when I get some I'll reset and torque the cap bolts for good.

 

[pnwboat]

Re: Success!

Re: Success!

Good job! Remember to run 25:1 fuel/oil mixture until you get that piston/rings broken in.

 

[HotTommy]

Passed the compression test

Passed the compression test

I hope the news that my engine passed the compression test will wrap up this thread. (I hate it when guys start a thread and never come back to say how it turned out.) With the engine buttoned up, the carbs opened, and the spark plugs grounded just to be sure, I ran jumper cables to the starter and spun the engine over to test the compression. All five cylinders were in the 140-145 PSI range. Most importantly, there was no significant difference in compression between cylinder 1 (the one that had suffered damage) and the rest. It also appears that the small amount taken from the head by the machine shop was not enough to make premium fuel a necessity.

Encouraged by this good news, I'll now take on the water pump and tilt/trim system. If all goes well, I may be able to fire it up for break-in in a week or so.

Thanks again to all who helped me get this far. I deeply appreciate it.

 

[pnwboat]

Re: Passed the compression test

Re: Passed the compression test

Glad everything worked out for you, and thanks for letting everyone know how it turned out. Happy Boating!