Milky fuel in carb intake force 85hp

[lgaytan]

thank you!

 

[lgaytan]

So I just took the head off and found a mess inside, piston#1 looks melted cylinder walls with a small scratch, piston#2 carbonized but no melt the cylinder walls have rougher scratches, piston#3 a lot of carbon no melt and no scratches in the cylinder how ever this one was dry and the other 2 were oily, any reason to that?
So now I guess I need to bore the cylinders 1 and 2, replace piston #1, should I change piston #2?
See pictures attached

Piston 1

 

[Nordin]

Pull the power head from the engine, split the power head and check the pistons and walls.
If the scratches are deep (you can feel them with your nails) then you have to bore and put in new oversize pistons.
If not you maybe only need to hone and put in new pistons.
If that is the case you have to measure the cylinders and check if you can go for new std. pistons or need to bore and put oversize in.
Maybe the bottom piston is reusable without doing any thing to it.

 

[The Force power]

Yes, there is both a torque spec and sequence for the cylinder head bolts....no sealers are used on the head gasket, put it on dry. If you don't have a factory manual here is the info from Mastertech Marine.....they have a lot of good information on their site.....torque spec for cylinder head bolts is 225 in lbs.
View attachment 393924

This is a 3-step torque-procedure,
The bolts should be tightened in the order specified to 75 in-lb, then 125 in-lb, then 175 in-lb, and finally 225 in-lb.

 

[topgun3690]

This is a 3-step torque-procedure,
The bolts should be tightened in the order specified to 75 in-lb, then 125 in-lb, then 175 in-lb, and finally 225 in-lb.

That would be a 4-step torque procedure....

 

[The Force power]

That would be a 4-step torque procedure....

If I do too many steps.....I trip

 

[The Force power]

Pull the power head from the engine, split the power head and check the pistons and walls.
If the scratches are deep (you can feel them with your nails) then you have to bore and put in new oversize pistons.
If not you maybe only need to hone and put in new pistons.
If that is the case you have to measure the cylinders and check if you can go for new std. pistons or need to bore and put oversize in.
Maybe the bottom piston is reusable without doing any thing to it.

I recently have tried a method I read to remove the piston without splitting the bock & just honed 1 cylinder wall.
I bought a used standard piston & now waiting on new piston-rings

 

[Nordin]

Yes, I have done this thing too.
Did it at a 70Hp Chrysler and at a 60Hp Chrysler.
Removed the connecting rod screws through the intake manifold.
Disassembling is no problem except to not drop the needle pins into the crankcase.
The needles are loose in the cage, the needle cage is not a complete unit.
Count the pins carefully, should be 16 pins.
BUT to reassemble it is a PIA, it is doable but you have to have patience.
You have to use assembling grease or similar to hold needles in place in the cage.
You maybe drop some needles a couple of times and have to fish them up from the crank case.
But as I said it is doable.

 

[lgaytan]

I read also about that method of disassembling through the intake manifold, but I decided to go the full way and now the motor is completely open. Found out all three pistons are broken, with broken rings, the scoring in the cylinders don't seem to be very deep, I'm have already honed the cylinders, they feel smooth, and to my habilities I measured the scores and seem to be like 0.002" deep so I will leave them as they are, having in mind I had 100/60/110 PSI with almost all rings completely broken and the pistons as well I imagine putting a new piston with new rings will take me to a safe place.
Now I have a problem with the part numbers, fortunatelly I haven't purchased anything yet. According to the marine engine website the part number for the STD rings is 39-817869A and for the pistons STD is F691015 , I had here already 2 sets of rings here that I purchased years ago and when trying them in the cylinder I see they don't fit, there is no gap where the ring closes together, so I think something is not right, either they are mislabeled or are not the right size, see pictures attached.
The maesurements I got from the bores are from 3.315" to 3.319", the specs accoridng to the service manual says 3.3130" - 3.3148", I think I should stay in STD size of piston and rings, or should I go to oversize? does anyone knows the right part numbers from this?

Thanks

 

[Nordin]

The part number for the rings is right for std rings.
The last digit 1 after the "A" says it is std.
The part number for the std piston must be a Chrysler/Force number.
Std piston from Quicksilver should be 834794T3 (whole assembly).
When you put the rings in the bore will they go down completely with no gap or will the end overlap?
If they go down completely with no gap they must be 010 oversize rings.
They can be used if you file the ends into right spec for the gap.
Be careful if you file them, they can break.

 

[The Force power]

I read also about that method of disassembling through the intake manifold, but I decided to go the full way and now the motor is completely open. Found out all three pistons are broken, with broken rings, the scoring in the cylinders don't seem to be very deep, I'm have already honed the cylinders, they feel smooth, and to my habilities I measured the scores and seem to be like 0.002" deep so I will leave them as they are, having in mind I had 100/60/110 PSI with almost all rings completely broken and the pistons as well I imagine putting a new piston with new rings will take me to a safe place.
Now I have a problem with the part numbers, fortunatelly I haven't purchased anything yet. According to the marine engine website the part number for the STD rings is 39-817869A and for the pistons STD is F691015 , I had here already 2 sets of rings here that I purchased years ago and when trying them in the cylinder I see they don't fit, there is no gap where the ring closes together, so I think something is not right, either they are mislabeled or are not the right size, see pictures attached.
The maesurements I got from the bores are from 3.315" to 3.319", the specs accoridng to the service manual says 3.3130" - 3.3148", I think I should stay in STD size of piston and rings, or should I go to oversize? does anyone knows the right part numbers from this?

Thanks

The measurements I got from the bores are from 3.315" to 3.319", the specs according to the service manual says 3.3130" - 3.3148", I think I should stay in STD size of piston and rings, does anyone knows the right part numbers from this?

Thanks

I have attached a piston / ring chart that may come in handy.
It may be easier/cheaper to go with Wiseco pistons & rings than to find the correct piston$ ??? now that you have to do all 3

 

[lgaytan]

I have attached a piston / ring chart that may come in handy.
It may be easier/cheaper to go with Wiseco pistons & rings than to find the correct piston$ ??? now that you have to do all 3

Thank you for the chart, it seems the part number of the rings I have are the right ones, but they don't fit, the ends overlap completely by a some milimeters I don't think filing them will help, it is a lot of overlap. Maybe they were mislabeled? although as you see in the pictures I have 2 boxes of piston rings labeled the same and neither of them fit the bores.
I will look at the weisco Pistons, I'm just trying to understand their webpage, I'm not sure how to select the right one for my outboard.

 

[lgaytan]

There's in ebay 3 used pistons... one bad (see link below), according to the listing they are 83.85 mm, my bores are 84.201 mm, would they work assuming the pistons are in good condition? What is the gap between bores and cylinders recommended?
This pistons are P/N F372015-3, and what marine engine webpage says mine should be is P/N F691015, would this work? I see in the chart there is another version of the 85HP outboard that the bore seems to be closer to the size I have, so they could work I think.

818052A 4 F372015-3 PISTONs (1bad piston) 818052T6 834795 force chrysler 85hp | eBay

Force Outboard 85HP 858V6B 1986 MOTOR LEG. Force Outboard 85HP 856FC6C 1986 MOTOR LEG. Force Outboard 85HP 858R8B 1988 MOTOR LEG. Force Outboard 85HP 853F8A 1988 MOTOR LEG. Force Outboard 85HP 858F7B 1987 MOTOR LEG.

www.ebay.com

Thanks

 

[The Force power]

It seems the part number of the rings I have are the right ones, but they don't fit, the ends overlap completely by a some millimeters I don't think filing them will help, it is a lot of overlap. Maybe they were mislabeled? although as you see in the pictures I have 2 boxes of piston rings labeled the same and neither of them fit the bores.

I'll look tonight at the rings I have (same part#) but yours don't look right?

 

[The Force power]

There's in ebay 3 used pistons... one bad (see link below), according to the listing they are 83.85 mm, my bores are 84.201 mm, would they work assuming the pistons are in good condition? What is the gap between bores and cylinders recommended?
This pistons are P/N F372015-3, and what marine engine webpage says mine should be is P/N F691015, would this work? I see in the chart there is another version of the 85HP outboard that the bore seems to be closer to the size I have, so they could work I think.
Thanks

These piston are used for many HP & years, I would verify the part# of the connecting-rods to see if they're correct

 

[lgaytan]

I'll look tonight at the rings I have (same part#) but yours don't look right?

Yes part numbers of my rings are 39-817869A as supposed to be but dont fit. The are completely overlap. Thanks for checking.

 

[The Force power]

Yes part numbers of my rings are 39-817869A as supposed to be but dont fit. The are completely overlap. Thanks for checking.

Yeah, the ring(s) you got are not the right ones; they should not overlap but bud-up with a slight clearance. to line them up with the location-pins on the piston
Strangely I could not find the required clearance in the manual?? these can be filed-down as Nordin suggested

 

[lgaytan]

Thanks Force Power, I have 2 books the Seloc and the Service manual.
Seloc says both TOP and LWR Ring End GAP is 0.006-0.016.
Service manual shows, TOP Ring 0.010"/0.020", LWR 0.006-0.016".
I think my rings are to big to filed down to that GAP, do you think they were mislabeled, both? I'm concerned of buying some others same part number as they should and not fitting.

 

[The Force power]

Thanks Force Power, I have 2 books the Seloc and the Service manual.
Seloc says both TOP and LWR Ring End GAP is 0.006-0.016.
Service manual shows, TOP Ring 0.010"/0.020", LWR 0.006-0.016".
I think my rings are to big to filed down to that GAP, do you think they were mislabeled, both? I'm concerned of buying some others same part number as they should and not fitting.

The rings you have are not the correct ones, (mislabeled) they overlap so there's no room the locating-pin; that is in the grooves of the piston (opposite of each other)
Have a closer look at mine (or google these rings) you'll see they are not the same; regardless of diameter/size
I'll have to take a deeper look in my manual (lol) , it must have these specs. you attached

 

[lgaytan]

Understand, so I will assume that my rings are mislabeled then if I get real 39-817869A they should fit to my bores?