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Author Topic:   Removing flywheel from outboard
pglein posted 04-17-2008 02:36 PM ET (US)   Profile for pglein   Send Email to pglein  
How the heck do I do this? I'm trying to tear down my 150hp OMC V6 (1985) so that I can get the block machined and rebuild it, but I can't get the flywheel off. I ran into this on my old Suzuki 25hp too, and just gave up and bought a new engine instead, but this time I plan to succeed.

I've got a three-way bolt-on style wheel puller, but when I tighten it down, all it does is bend the puller, and last night, it even ripped one of the bolts right out of the threads on the flywheel. I'm going to have to drill and re-tap it right on the engine. Obviously there is some sort of trick to this. Does anyone know?

contender posted 04-17-2008 02:56 PM ET (US)     Profile for contender  Send Email to contender     
First make sure the (bolts) threads are all the way in the flywheel so they do not strip out, second after you drill and retap the threads follow number one. Make sure the three bolts are level and straight to the drive shaft. Once you have applied pressure on the puller(center bolt) (hope you are using all 3 bolts set at 60 degrees to form a triangle) now tighten the center bolt and hit it with a hammer, tighten the center bolt about 1/2 turn and repeat and repeat until one time the flywheel will pop off after hitting it. Make sure you are/were using the correct threads (bolts) on the flywheel they should not striped out...good luck
an86carrera posted 04-17-2008 03:04 PM ET (US)     Profile for an86carrera  Send Email to an86carrera     
Use a high quality forged puller and tap the flywheel with the puller in place tightened up.

It seems impossible to strip the threads if the screw was fully threaded in so you may have some more theads down in the hole. Run a bottoming tap in the hole to clean the threads first, you may also find that there is room to tap more threads in the original hole.

Drilling and tapping in place could be dangerous to the electronics, be careful.


an86carrera posted 04-17-2008 03:05 PM ET (US)     Profile for an86carrera  Send Email to an86carrera     
Like minds
pglein posted 04-17-2008 04:26 PM ET (US)     Profile for pglein  Send Email to pglein     
The bolt that came out was not threaded in all the way. I figured it would probably happen. I was not able to find three bolts that would fit. It's a fine-thread hole, and the Craftsman puller I bought did not come with the right size, nor was I able to find more than two that matched in the shop, or on the engine. The third one was the same thread, but not as long, which meant that, in order to keep the puller level, it couldn't be threaded in all the way. regardless, it does seem rather hard to get off. Almost like there's something holding it on. I've removed the bolt off the top, but that's it. I couldn't see anything else that could be keeping it on. We tried liquid penetrant, precussive persuasion, and brute force, the latter of which resulted in the stripped threads. That thing is ON there.

I will try again tonight, using more gentle pulling, and less gentle "tapping". My concern was that I would mushroom the top of the crankshaft, which I really don't want to do. The crank is the one internal piece I was hoping to save.

Martino posted 04-17-2008 06:26 PM ET (US)     Profile for Martino  Send Email to Martino     
You need the correct puller. It somes with the correct bolts. It is about 1/2 to 3/4 inches thick, solid steel, and would never bend or deform. Beg, borrow, or steal one. I usually tighten the %^** out of it late in the day, and let it sit overnight. I usually find that by morning it has come loose without all the usual cussin. I think they run in the $75 range. You could buy one, use it, and probably get all of your money back on Ebay!
seahorse posted 04-17-2008 10:46 PM ET (US)     Profile for seahorse  Send Email to seahorse     
Be very careful and realize that when you hit the center bolt with a hammer, that shock wave is absorbed by the crankshaft journal "cheeks" and the lower thrust ball bearing. Bent cranks and dimpled ballbearings are not unheard of. Sometimes the motos will just develop a whine from the deformed balls inside the bearing.

You should use an outboard flywheel puller that is built a lot stouter than automotive steering wheel and vibration dampner pullers.

sosmerc posted 04-17-2008 11:06 PM ET (US)     Profile for sosmerc  Send Email to sosmerc     
In addition to all of the above: I have found that in some instances it will help to tap in a wedge between the block and the flywheel INLINE with the keyway. Have a good deal of tension on the center bolt before "tapping" in the wedge.
I got this "tip" from (believe it or not) the factory manual for Force outboards. They even had a special "wedge" tool for the job. Also, those awful engines had a nice large flat area on the top of the crankcase to put the wedge between. But I have used this technique on other engines with success.
pglein posted 04-18-2008 02:41 PM ET (US)     Profile for pglein  Send Email to pglein     
I finally got it off. The trick was to use less tension on the puller, and more banging. Rather than go to town on the crankshaft, we focused instead on the under side of the flywheel. I figured that would be cheaper to replace than the crank. Now I just need to find a good machine shop to bore out the cylinders. My friend, who is very experienced with automotive engines, but not as much with two strokes, said it looked like it had gone without oil. I'm inclined to agree, but I'm also no expert on the oiling characteristics of two stroke engines. Only one cylinder was damaged, but it was damaged bad. There was still oil in the VRO tank, but it was low.
seahorse posted 04-18-2008 06:30 PM ET (US)     Profile for seahorse  Send Email to seahorse     
My friend...said it looked like it had gone without oil. I'm inclined to agree...

Only one cylinder was damaged, but it was damaged bad. There was still oil in the VRO tank, but it was low

Read this article on the "VRO" and you will see that it cannot damage just one cylinder. If it quit oiling, all of the cylinders would be damaged because the "VRO" premixes the gas and oil before it gets to the carburetors.

EIKNIB posted 04-18-2008 07:28 PM ET (US)     Profile for EIKNIB    
sosmerc, Ive used the wedge system too. cut two wedges from a 2x4 and found a flat spot on the block 180 degrees from each other. also put a strain on the flywheel hanging from a chain from a cherry picker. lifted the motor about 1/2 inch. Everyone seems to knock Force-Chrysler. They are very simple to work on, even for me and I`m no outboard tech. I run a `72 Chrysler 75hp with a Chrysler racing mid and gearcase on my Antique Class F runabout at the AOMCI meets. Its a sweet running simple 3 holer. I removed the CD unit, they never work, and hooked up battery ignition. Very simple to do. The motor is flawless, if only I could find the right prop.
Here`s a pic of an early `70`s 135 hp Chrysler Stacker. They gave the Mercs of that era a good run, in OPC racing, but factory backing was lacking
sosmerc posted 04-18-2008 08:49 PM ET (US)     Profile for sosmerc  Send Email to sosmerc     
I know there are many old Chrysler and Force engines out there still running and delivering faithful service. But they probably have experienced owners that know how to care for them...and feed them clean quality oil and fuel.
In my experience, many force engines ended up in the hands of first time boaters that had little or no knowledge of preventative maintenance or the importance of proper oil and fuel. I blame alot of this on the un-educated Bayliner salesmen that sold a ton of first time boaters down the river!
Martino posted 04-19-2008 09:05 AM ET (US)     Profile for Martino  Send Email to Martino     
I would strongly urge a marine machine shop. They know how too not only bore the cylinders, but how to finish off the cylinders around port openings. Most auto shops don't have that experience.
pglein posted 04-22-2008 01:23 PM ET (US)     Profile for pglein  Send Email to pglein     

I'm with you on that. I don't see how just one cylinder could have been damaged by a lack of oil in the VRO tank. However, that still leaves me scratching my head as to how it DID happen. The bearings and rings seemed just fine on the other 5 cylinders. Could a lack of fuel getting to the #6 cylinder have caused it? The carb and reeds looked just fine. The only damage I can see is to the piston, cylinder, and rings. It's almost as though the ring just plain wore out, which I suppose is possible, but the others don't seem to show any signs of damage at all.

pglein posted 04-22-2008 01:30 PM ET (US)     Profile for pglein  Send Email to pglein     
Here is a picture of the offending piston, by the way: johnsonpiston.jpg?imgmax=512

towboater posted 04-22-2008 02:02 PM ET (US)     Profile for towboater  Send Email to towboater     
Which cyl Pete?

Intake valve & spring ok?
Cracked head?

Just food for thought, Im not a 2 stroke expert.


towboater posted 04-22-2008 02:05 PM ET (US)     Profile for towboater  Send Email to towboater     
Maybe the cooling system wasnt getting water to that cyl.


Tohsgib posted 04-22-2008 02:34 PM ET (US)     Profile for Tohsgib  Send Email to Tohsgib     
It does not take a lot to fry a cyl. Especially if one of the top cyls which are the hottest. A litle detonation and BOOM. Again I would think it is in the carb but also disconect the VRO and pre-mix after rebuild. Usuallt you can rebuild just one cyl but with that many hours I would do all 6 pots. Not gonna be cheap.
pglein posted 04-22-2008 03:56 PM ET (US)     Profile for pglein  Send Email to pglein     
It was #6, which is the bottom, port-side cylinder. I've torn down engines that overheated, and that's not what happened here. Usually, when a cylinder overheats, the piston will soften under the heat, and as it slides up the cylinder wall past the top of the exhaust valve, the hot exhaust travelling out of the valve will want to pull the softened piston material out with it. Then, this ever-so-slightly deformed piston edge hits the top of the exhaust valve and, BAM! it stops dead in its tracks and siezes up. That's not what happened here. In this case, the engine turns over just fine, but there's no compression on the #6 cylinder. Disassembly revealed that there was significant scoring on both the cylinder wall and on the sides of the piston. The rings had worn down to the point where they were flush with the side of the piston, and could not be removed. Again, all other pistons were in perfect condition.

My plan is to rebuild the entire thing. First off, simply due to it's age, this seems like a prudent thing to do. Secondly, rebuild kits are only available in one-size sets. Lastly, I wouldn't want to throw off the balance of the crankshaft by having a different sized piston in just one cylinder.

I will also have the starter rebuilt, replace the impeller for good measure, and replace the entire wiring harness with the newer System Check version. I'm still deciding whether or not to replace the VRO/fuel pump, as it was already recently replaced. I don't want to convert it to pre-mix, as I trust the pump to not fail more than I trust the fuel/oil to not settle and separate in the 65 gallon tank, and certainly myself to do the mixture properly every time.

contender posted 04-22-2008 10:33 PM ET (US)     Profile for contender  Send Email to contender     
You are rebuilding a 1985 outboard? unless you are getting the parts cheap or free I would be looking for a use motor. Not to be a kill joy but from reading your threads it sounds like you are in over your head. If your engine ran with out oil you need to check your crank and probably will have to turn it as well, now you will need to purchase over size bearings for the rods and crank. Your engine has to be rebore (all 6 cylinders) and purchase new pistons and rings. You will need a new (full set) gasket set, carbs rebuilt, new wires, new water pump, and hoses. And not to forget each part needs be cleaned and checked then painted. (And this is a 20 year old engine may not find all the parts) Now lets talk who is going to put this all back together? Do you have a torque wrench, piston ring clamp, ring pliers just to name a few. You need to take every part apart and check for any metal shavings (like your fuel pump) You have also stated your friend (the mechanic) does not have experience with 2 stroke engines, so who/whom is going to help you assemble the engine? Again not to bust your bubble (I do not know you nor your machine capabilities) however, you could not remove your flywheel from your engine and doing so you damaged it. I would not want you to do all the work and spend the money only to have your engine throw a rod on the first time out. (I also would do away with the VRO and pre mix the fuel)... best of luck to you but think about it.
towboater posted 04-23-2008 02:45 AM ET (US)     Profile for towboater  Send Email to towboater     
Yo contender, have you priced new engines lately? Dont forget to add rigging costs. 150 hp...$12k on the low side.

The stuff you mention is nessessary, and not cheap but still, less than half the cost of a new motor and he will basically have a new motor...if not better.

Of course we could get into the value of gas efficient new engines but...the $6-7k rebuild savings will buy a lot of gas/oil relative to how often he uses the boat. The more hours he runs above average per season, a fuel efficient engine becomes more valid because it wont take as long to break even. I think Pete knows what he is doing.


pglein posted 04-23-2008 04:54 PM ET (US)     Profile for pglein  Send Email to pglein     
This will not be the first engine I've rebuilt, but it will be the first two stroke. I've disassembled quite a few 2 strokes over the years, this will only be the first time I've re-assembled one. My friend the mechanic, has rebuilt numerous automotive engines and between us we have all the tools and skills necessary to do this, aside from the actual machining itself. The only damage to the internals is on one cylinder. The crank is just fine, and does not need to be machined. There are rebuild kits available that include new pistons, rings, bearings, gaskets, and seals for the whole engine, sized to fit anything from .010 to .040 over for under $1,000. I'm budgeting that, plus another $1,000 for other parts and services, plus whatever it costs to get the block machined. Right now, I'm having trouble finding anyone qualified to machine the block, so that may end up being the critical motivator towards getting a newer used motor.

Removing the flywheel was the one conundrum I ran into when disassembling, and it's really just due to the fact that it was on there so damn tight. It seems to be a common theme on outboards, as this is actually the third time I've encountered it. In the past, I just gave up, but those were much smaller, cheaper motors. In this case, persistence paid off and it came off with, what turned out to be, no damage.

The one thing that is the wild card is the machining. What I'm hearing from the marine mechanics I've talked to, is that there isn't anyone around who knows how to machine a two-stroke block. That seems ludicrous to me, since they were still being made only a few years ago, but that's what I'm hearing. The other thing I'm hearing is "it won't be cheap". I understand that, but with a new motor likely to run well over $10,000, it would have to be VERY expensive to come anywhere near the cost of a new motor. Even a used FICHT is going to cost $4-6,000, and who knows what kind of condition that'll be in. I'd rather spend $2-3,000 and have a motor that I know is in top shape. Also, I'm vehemontly anti-4-stroke when it comes to outboards, so there's no way I'm hanging one of those piggy, overweight, high maintenence, monsters on the back of my boat.

Over my head? Maybe. But if you want to learn to swim you have to get out of the shallow end at some point.

MDI posted 04-23-2008 09:07 PM ET (US)     Profile for MDI  Send Email to MDI     

I checked with our local outboard shop in Gig Harbor & they have used both these shops for outboard block machining in the past: Quality Boring (Paine Field area) 425-741-1125 and Dave Marty (in Olympia area) 360-491-0666.

Hope this helps.


contender posted 04-23-2008 10:41 PM ET (US)     Profile for contender  Send Email to contender     
Hey I'm all for you, like I said I did not know your skill level. I use to work for an engine shop (H.C.Wilcox) building engines in Miami over 25 years ago, back then I only knew of one person that would rebore 2 stroke engine blocks and the engine had to be ALL APART, this guy did not even want one bolt on the block. You need to check the block like I said the block is 20 years old, how good are the water passages, need to check for cracks. You are tearing down the whole engine, do it right, inspect everything. When you rebore the one cylinder are you going to put it back to standard? The person that does the work will want the engine all apart, not to mention you need to be able to clean out all the shavings. I would try and call some outboard racing guys, or find a high performance marine center, or even some guys who race cars, one of these place could lead you to a machine shop that does the work you require. Again I agree with you I still do not understand the huha about 4 strokes, Give me a 2 stroke anyday, Well wish you the best on your task at hand, just take your time...good luck
EIKNIB posted 04-24-2008 07:51 AM ET (US)     Profile for EIKNIB    

I`m with you, If I had your skill level and confidence, I would certainly do it myself too, and you will never see a 4 stroke (fake outboard) on any of my boats either. My only question for you is, is this a salt water motor. If it is I assume you have owned it a long time, and took care of it. There seems to be a ton of really good used motors in the upper Midwest where there is only fresh water and the season is short. That's where I get mine from, even though the shipping to Florida is costly. I seem to see a lot of outboard re builders advertising in Fl. all the time, so there must be machine shops here with 2 stroke knowhow. I`m sure this isn`t rocket science for the capable. Go for it.


pglein posted 04-24-2008 01:57 PM ET (US)     Profile for pglein  Send Email to pglein     
Thanks so much for the erferral. Was it Lighthouse that gave you that name? I will be calling the guy in Olympia shortly.

As for my plan to rebuild, I will be getting the block caustic tanked before machinung, and it is already 100% torn down; no bolts, no gaskets, no parts on it. And I'll repaint it once it's machined.

I will assess the options once the machinist gets a look at it. I may end up buying a reconditioned FICHT or similar from one of the many online resellers in Florida. My friend went this route with great success.

MDI posted 04-24-2008 02:25 PM ET (US)     Profile for MDI  Send Email to MDI     

Yes it was Lighthouse I called. I have delt with Rich and Mike for many years,both great guys. Hope everything works out for you.


towboater posted 04-24-2008 10:01 PM ET (US)     Profile for towboater  Send Email to towboater     
Pete, if Lighthouse doesnt pan out, check out local quad or bike shops for 2 stroke machinist info.

Banshees, Harley's, Honda TR's are all 2 strokes that are bored out all the time.


an86carrera posted 04-24-2008 10:23 PM ET (US)     Profile for an86carrera  Send Email to an86carrera     
I have a 2000 Ficht with 800 hrs on it it has been great for me. I paid $3000 with a boat 4 years ago and re-rigged it onto my boat.

All Fichts are not bad they just need good batteries.

Gas mileage is 3mpg at 30mph on my 22' Proline Sport and will do almost 50mph.

Happy camper here, someone else here has same motor with 1600 hrs on it.


Tohsgib posted 04-25-2008 10:37 AM ET (US)     Profile for Tohsgib  Send Email to Tohsgib     
Place by me has a rebuilt 2003 HPDI 150 with 1 yr warranty for $5200. Can't justify a rebuild with that.
jgkmmoore posted 04-28-2008 03:25 PM ET (US)     Profile for jgkmmoore  Send Email to jgkmmoore     

A huge percentage of single piston cooking on a V6 2 stroke is because the carb that feeds the cylinder that grenaded, was plugged up somewhere.DO NOT slap the same carbs back on without rebuilding them!!!! I have seen too many folks cook the same piston 20 minutes after the rebuild.
When you mentioned exhaust 'valves', I assumed you meant exhaust 'ports' (only 4 strokes have valves of the interference type). Reed valves are a whole different ballgame.
99% chance this problem was not caused by the VRO. VRO is often misdiagnosed, and very seldom guilty.

If you choose to mix your own, please remember:
When you first start premixing, don't let someone interrupt your train of thought until you get the right amount of oil into the tank.If that happens, and you forget whether you poured the oil in or not, ALWAYS err in the direction of TOO MUCH,rather than 'thinking' you put it in.Double mix will smoke more,and may foul your plugs when idling/trolling. 1 more set of plugs is a helluva a lot cheaper than a rebuild.

pglein posted 04-28-2008 05:20 PM ET (US)     Profile for pglein  Send Email to pglein     
I don't believe I ever mentioned valves. I'm well aware that there are none. I believe someone else did.

I don't plan to premix. As I stated before, I trust the pump more than I trust myself. Also, having disassembled a VRO pump before, I know that the pump relies on the oil flowing into it to remain properly lubricated. Simply elmiminating the oil inlet, and premixing, will only lead to repeated premature fuel filter failures.

I do plan to rebuild the carburetors. That is one possible culprit, but I would expect to see some damage to the other cylinder fed by the same carburetor as the one that failed, which I did not see. Regardless, it's still worth doing, given how inexpensive and easy it is.

pglein posted 05-30-2008 02:54 PM ET (US)     Profile for pglein  Send Email to pglein     
Well, it's done, and she runs well. Still needs some fine tuning (idles high, etc), but I finally got her out on the water and ran her around. The motor seems to run better since the rebuild. Much quieter and smoother, even with the high idle. Starts on the first turn of the key. I removed the doel-fin that was on the engine and she hops up on a plane just fine without it even with five passengers, three of them across the rear bench seat. It clearly has more power, but it's still in the break-in period, so I haven't opened her up yet. We'll see what kind of speed numbers I get. Pre-rebuild it topped out at 40 knots.

I replaced:
Pistons (Wiseco, teflon coated)
Wrist pins
Writs pin bearings (re-used cages)
Rod bearings (caged assemblies)
Lower main bearing
All gaskets
Thermostats (SS)
Water pump (SS rebuild kit including impeller, housing, bolts, key, plate, and o-rings)
Starter (rebuilt, off-shelf)
Carburetor gaskets and valves (standard rebuild kit)

I still need to replace:
Spark plugs
Plug wires
Fuel hoses

I did NOT replace the fuel/VRO pump. The one on the engine is nearly brand new, plus I have another one new in the box, ready to go on, in case it fails.

I still don't know what caused the initial failure, but I do not believe it was a faulty VRO pump or a bad carubretor. 5 of the 6 cylinders were perfect and showed no damage. #6 was toast. There was nothing wrong with any of the carburetors or vanes. If fuel and oil was making it to one cylinder, it was probably making it to all 6. If it wasn't making it to the pump, I'd have seen some sort of damage or wear to the other cylinders.

After running it a little more, I plan to pull the heads and inspect the cylinders for wear, just to be sure everything is as it should be.

contender posted 05-30-2008 03:09 PM ET (US)     Profile for contender  Send Email to contender     
Your thinking is correct about the vro, but the piston picture shows lack of lube. Why don't you remove the vro and just mix your oil to be safe, also I would mix some oil in the gas for the hell of it being a new engine, nice job on the rebuilt...good luck
pglein posted 06-01-2008 11:39 AM ET (US)     Profile for pglein  Send Email to pglein     
I believe that the VRO system will be reliable and safe as long as I upgrade to the newer sensors and gauges to alert me to any problems right away. Also, I have a four stroke kicker motor that pulls from the same tank, so I don't want to pre mix.
towboater posted 06-01-2008 12:28 PM ET (US)     Profile for towboater  Send Email to towboater     
Pete, if #6 hole is fed by the lower carb, I would agree the fuel bowl was probably clogged (gravity factor).

Im curious if you bored or honned #6 cyl only or all?


contender posted 06-01-2008 02:06 PM ET (US)     Profile for contender  Send Email to contender     
The 4 stroke would run on the pre mix, may smoke a little but you would be lubricating the cylinders and it would be safe...good luck
pglein posted 06-02-2008 11:00 AM ET (US)     Profile for pglein  Send Email to pglein     
All 6. To keep the crank balanced.

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