88 SPL Starting/Running Issues

[healey8390]

Re: 88 SPL Starting/Running Issues

If your rings are rebounding then they're not stuck so I don't see a decarb or my method helping. It looks like all your hopes are on the head gaskets! I would use another comression tester to double check though! A mechanic I work with has a name brand tester and it reads low so they're prone to being inaccurate.

 

[James R]

Re: 88 SPL Starting/Running Issues

I have the same motor on my Aquasport 175. Great motor. All compressions are up around 110-115.
I have rebuilt several of these and larger and it is usually no problem to remove the heads for inspection. With the heads off you can see if there is any scoring, bad wear, carbon etc. There may also be evidence if the gaskets have failed. With a bore gauge you can check for size and out of round of the bores to give you a better idea of the the real condition.

 

[emdsapmgr]

Re: 88 SPL Starting/Running Issues

Agree with healey. If the rings are carboned up, that will be visible when you view through the ports, as your picture indicates. Your rings look fine. The decarb may not help much. Hard to explain the low compression, unless the engine were severly overheated at some point and the rings lost their tensile strength. At this point, have a close look at the head and head gaskets. Maybe the head is warped slightly or the seal rings on the gaskets are bad. Even recheck the torque values on the heads....

 

[Treshuevos]

Re: 88 SPL Starting/Running Issues

Thanks very much guys. Looks like the next step is the heads. I'll keep you posted.

I really appreciate all the help!

 

[Treshuevos]

Re: 88 SPL Starting/Running Issues

So I pulled the heads tonight and here is what I found...Port Side first

Port Head



Port Cylinders







Port Water Deflectors

 

[Treshuevos]

Re: 88 SPL Starting/Running Issues

Starboard Side...

Starboard Head



Starboard Cylinders







Starboard Water Deflectors

 

[Treshuevos]

Re: 88 SPL Starting/Running Issues

Do any of the above pictures look like my compression issues are gasket related? The port side temperature switch lead literally fell out as I was backing the head cover bolts out. This, combined with the clogged/pinched water deflectors, are leading me to believe there was a overheat situation which ultimately blew the head gasket(s). Again, with my untrained eye it's tough for me to tell.

As always, any insight would be greatly appreciated.

 

[emdsapmgr]

Re: 88 SPL Starting/Running Issues

Pistons have the normal carbon coating and look well oiled. Normal. The lower and middle water deflectors look properly positioned. Have you tried taking a compression reading with another gauge?

 

[racerone]

Re: 88 SPL Starting/Running Issues

Install new deflectors !

 

[racerone]

Re: 88 SPL Starting/Running Issues

Install new deflectors !------Heads will be warped so they need to be touched up to be flat.-----Piece of glass and some valve grinding compound can be used to get them flat.

 

[Treshuevos]

Re: 88 SPL Starting/Running Issues

Pistons have the normal carbon coating and look well oiled. Normal. The lower and middle water deflectors look properly positioned. Have you tried taking a compression reading with another gauge?

I agree, as near as I can tell the cylinders looked fine.

I wasn't sure how the water deflectors operated. I guess I originally assumed they where designed for water to pass through them...but they literally just deflect the cooling water? So as long as they are in the proper position and not deteriorated they should be okay? Not a huge deal to replace them but I figure why bother if the clean up well and perform as designed.

Unfortunately, I haven't been able to get a hold of another compression tester...still working on it. I really wanted to eliminate a cylinder and or cylinder head issue and since removing the heads wasn't a major undertaking I figured I'd get that out of the way. From the pictures, are there any signs that one or both could have blown?

Thanks again!

 

[Treshuevos]

Re: 88 SPL Starting/Running Issues

Install new deflectors !------Heads will be warped so they need to be touched up to be flat.-----Piece of glass and some valve grinding compound can be used to get them flat.

So if the deflectors clean up and appear like new, do you still recommend replacing them?

I checked the heads with a straight edge at just about every angle and they are true. Would checking it (and ultimately flattening them) with a piece of glass reveal something different?

Thanks again!

 

[racerone]

Re: 88 SPL Starting/Running Issues

Clean up the gasket surfaces and hold them together.----Look and see for light between the surfaces.----I have repaired outboards for many , many years and every older head I have seen is warped.------------It is just that some folks do not understand this concept.

 

[Treshuevos]

Re: 88 SPL Starting/Running Issues

Clean up the gasket surfaces and hold them together.----Look and see for light between the surfaces.----I have repaired outboards for many , many years and every older head I have seen is warped.------------It is just that some folks do not understand this concept.

I'm sure I fit in that category...I'll clean them up and do as you suggest.

Thanks again

 

[Treshuevos]

Re: 88 SPL Starting/Running Issues

Cleaned up the head surfaces and held them together. There is a definite "wobble" from top to bottom, albeit very minor, but it is there. Doesn't appear with the straight edge but it does when you hold them together as suggested.

I'll get ahold of a piece of glass and some valve grinding compound and go to work!

Thanks again.

 

[James R]

Re: 88 SPL Starting/Running Issues

Doesn't look like a happy motor with all the salt build up. That will need to be addressed. Difficult to be sure but it looks like someone has attempted a manual hone of the cylinders at some point. I think that measurement will show worn and out of round cylinders. Someone else may be able to say what the shiny patches are on the pistons. I have been fortunate in all the motors that I have worked on I have not seen a water ingress situation which. I am told. cleans the tops of pistons.

 

[Treshuevos]

Re: 88 SPL Starting/Running Issues

Doesn't look like a happy motor with all the salt build up. That will need to be addressed. Difficult to be sure but it looks like someone has attempted a manual hone of the cylinders at some point. I think that measurement will show worn and out of round cylinders. Someone else may be able to say what the shiny patches are on the pistons. I have been fortunate in all the motors that I have worked on I have not seen a water ingress situation which. I am told. cleans the tops of pistons.

I agree...I intend on cleaning all of the salt buildup I can get to prior to closing things up. I just wanted to show the actual condition of things in the event it helped diagnose potential issues.

Not sure about the attempted manual hone but all (4) cylinders measured between 88.89mm-88.90mm on my digital micrometer. Granted, that measurement was only on the top of the cylinder (where they would reach). Should I invest in a set of telescoping gauges to measure the other dimension shown in the manual? For what it's worth I ran the straight edge between the (2) recommended areas and didn't see any daylight.

Not sure about the clean patches either...I assumed the carbon buildup just flaked off in those areas.

Sidenote: I snapped the heads off of (3) of the center head cover bolts. Any suggestions on removing the studs? What would be the risk of reassembling as is (i.e. not removing/repairing the studs)?

Thanks again everyone!

 

[healey8390]

Re: 88 SPL Starting/Running Issues

The deflectors are only $4 so it wouldn't make sense to not replace them while your in there.

I've been burned by checking a head with a strait edge on a car head, it'll only show a blatant warpage. A warpage not visible to the naked eye is *plenty* to cause a drop in compression or in my case a no start.

Like another poster say you may have a water ingress issuse due to the heads/gaskets so it's looking better for you!

 

[James R]

Re: 88 SPL Starting/Running Issues

While you have the heads off it makes sense to measure the bores correctly. You may be able to borrow a bore gauge from an auto parts store or have a local shop do the measuring for you.
Removing bolts is not difficult. If you have a protruding piece of bolt then a lot of heat and vice grips will do it. If the bolt has snapped off at the surface or just below you can use a wire feed welder. Sit a steel washer of a size similar to the bolt and weld the inside to the bolt. Take a new hex head bolt and weld that to the bolt/washer assy. Use an impact wrench and spin the old bolt out. Run the threads with a Tap to clean them. Drilling is usually not very successful.

 

[Treshuevos]

Re: 88 SPL Starting/Running Issues

The deflectors are only $4 so it wouldn't make sense to not replace them while your in there.

I've been burned by checking a head with a strait edge on a car head, it'll only show a blatant warpage. A warpage not visible to the naked eye is *plenty* to cause a drop in compression or in my case a no start.

Like another poster say you may have a water ingress issuse due to the heads/gaskets so it's looking better for you!

You guys convinced me...I have already ordered new deflectors and temperature senders.

Hopefully it is just the gaskets!

Thanks.

While you have the heads off it makes sense to measure the bores correctly. You may be able to borrow a bore gauge from an auto parts store or have a local shop do the measuring for you.
Removing bolts is not difficult. If you have a protruding piece of bolt then a lot of heat and vice grips will do it. If the bolt has snapped off at the surface or just below you can use a wire feed welder. Sit a steel washer of a size similar to the bolt and weld the inside to the bolt. Take a new hex head bolt and weld that to the bolt/washer assy. Use an impact wrench and spin the old bolt out. Run the threads with a Tap to clean them. Drilling is usually not very successful.

I'm working on sourcing a bore gauge as we speak...I agree now's the time to verify.

Thanks for the tip on the bolt removal...I'll give it a shot.

Thanks!