What could cause case sealant failure on almost new PV motor?

[kevbo]

I have had success using high strength loctite between the bearings and case. It will often prevent all fretting, everything must be perfectly clean though . Kawasaki had huge fretting problems before 1994 then they installed plastic bands around the bearings and fretting largely vanished.

 

[JKMike]

I have had success using high strength loctite between the bearings and case. It will often prevent all fretting, everything must be perfectly clean though . Kawasaki had huge fretting problems before 1994 then they installed plastic bands around the bearings and fretting largely vanished.

Any preference on which #. I'm assuming your talking about the bearing retainer.

 

[DylanS]

i use 648 green** should be the close fit stuff

 

[kevbo]

I have used 609 and 271.

 

[WFO Speedracer]

Any preference on which #. I'm assuming your talking about the bearing retainer.

We always used a thin pink film of red loctite to secure the beading in the cases.

 

[JKMike]

What do yaw think about this cylinder wear for only having 8 hours? I keep going back and forth on whether I should freshen up the crosshatching.

 

[DylanS]

Looks like it’s seen some debris/metal on metal most likely from water ingestion. Are there any spots that catch your nail?
That’s looking a little rough for 8 hours but I’ve seen similar on engines that had guys learning how to backflip on them and throwing tons of water down the carbs.

 

[JKMike]

Yea that's what i was afraid of. There isn't anything i am able to catch a nail on but i also cant see the crosshatch anymore in a few spots. Also I honestly don't think i have thrown a lot of water down the carbs as i was pretty easy on it last year since this was my first real motor and i was trying to get everything dialed in.

Could overcooling the motor have anything to do with those marks? I did have some trouble initially with keeping the motor up around 140 deg F when i built it. I had 2 x 1/2" lines coming out of the head initially but i ended up lowering those to 3/8" to help with that issue.

 

[JKMike]

Looks like it’s seen some debris/metal on metal most likely from water ingestion. Are there any spots that catch your nail?
That’s looking a little rough for 8 hours but I’ve seen similar on engines that had guys learning how to backflip on them and throwing tons of water down the carbs.

What are your thoughts on freshening up the crosshatching?

 

[DylanS]

What are your thoughts on freshening up the crosshatching?

You should clean the bore up as best as you can around the areas that you can no longer see the cross hatching to get a really good look at what you are dealing with. You can get away with a lubricated green scotch bright pad and light pressure to scrub the surface down and get a better idea on how that cross hatching looks.
Personally I would take it to a reputable machine shop and have them inspect it to make sure you’re still within tolerance and to see if you can get away with a simple honing to correct your issue. It’s very hard for me to tell from the images, I would assume you could get away with a light rehoning seeing as you don’t have any nail catchers.
I’m sure you’re aware but as you lose your cross hatching it begins to hinder the ability of the sleeve to retain and spread oil across its surface so if you can see any specific spots that are “polished” in appearance those spots will continue to wear at an accelerated rate with more run time.

You could send a hone down it at home if you’re comfortable with it and have the skills and tools necessary to do so properly. But, even with that stroker crank, it seems highly odd to me that you have that level of wear in 8 hours without having some sort of major issue. I would have the cyls inspected by a shop to make sure they aren’t out of round and there isn’t anything funky going on with them then have them correct the issue.
You could continue to run it the way it is but it will only continue to get worse and you’ll end up needing to sleeves or pistons/bore faster than you should.
Seeing as these engines are stupid expensive and so are their parts I personally would fix this issue now rather than later.
You will also want to inspect your rings for any obvious damage.

As far as the cause for this wear, there could be several things to consider.
Debris left in the engine when assembled, water ingestion, over heating, being run hard before warming up, inadequate oil to fuel ratio or oil that isn’t up for the job. When you got this engine was the bore done professionally? Were the pistons and rings new? Was the engine broken in properly? Regardless if the cross hatching is gone it is an issue that should be corrected and you’ll want to try to narrow down what caused this to avoid having the same issue in another 8 hours.
I just reread the thread and you said the cases wouldn’t hold any pressure, did the engine run away on your really bad when the issue reared its head? It could’ve been running pretty lean for a while before you realized what was going on too.

 

[JetManiac]

You should clean the bore up as best as you can around the areas that you can no longer see the cross hatching to get a really good look at what you are dealing with. You can get away with a lubricated green scotch bright pad and light pressure to scrub the surface down and get a better idea on how that cross hatching looks.
Personally I would take it to a reputable machine shop and have them inspect it to make sure you’re still within tolerance and to see if you can get away with a simple honing to correct your issue. It’s very hard for me to tell from the images, I would assume you could get away with a light rehoning seeing as you don’t have any nail catchers.
I’m sure you’re aware but as you lose your cross hatching it begins to hinder the ability of the sleeve to retain and spread oil across its surface so if you can see any specific spots that are “polished” in appearance those spots will continue to wear at an accelerated rate with more run time.

You could send a hone down it at home if you’re comfortable with it and have the skills and tools necessary to do so properly. But, even with that stroker crank, it seems highly odd to me that you have that level of wear in 8 hours without having some sort of major issue. I would have the cyls inspected by a shop to make sure they aren’t out of round and there isn’t anything funky going on with them then have them correct the issue.
You could continue to run it the way it is but it will only continue to get worse and you’ll end up needing to sleeves or pistons/bore faster than you should.
Seeing as these engines are stupid expensive and so are their parts I personally would fix this issue now rather than later.
You will also want to inspect your rings for any obvious damage.

As far as the cause for this wear, there could be several things to consider.
Debris left in the engine when assembled, water ingestion, over heating, being run hard before warming up, inadequate oil to fuel ratio or oil that isn’t up for the job. When you got this engine was the bore done professionally? Were the pistons and rings new? Was the engine broken in properly? Regardless if the cross hatching is gone it is an issue that should be corrected and you’ll want to try to narrow down what caused this to avoid having the same issue in another 8 hours.
I just reread the thread and you said the cases wouldn’t hold any pressure, did the engine run away on your really bad when the issue reared its head? It could’ve been running pretty lean for a while before you realized what was going on too.

Well said.

 

[JKMike]

You should clean the bore up as best as you can around the areas that you can no longer see the cross hatching to get a really good look at what you are dealing with. You can get away with a lubricated green scotch bright pad and light pressure to scrub the surface down and get a better idea on how that cross hatching looks.

Personally I would take it to a reputable machine shop and have them inspect it to make sure you’re still within tolerance and to see if you can get away with a simple honing to correct your issue. It’s very hard for me to tell from the images, I would assume you could get away with a light rehoning seeing as you don’t have any nail catchers.

I’m sure you’re aware but as you lose your cross hatching it begins to hinder the ability of the sleeve to retain and spread oil across its surface so if you can see any specific spots that are “polished” in appearance those spots will continue to wear at an accelerated rate with more run time.



You could send a hone down it at home if you’re comfortable with it and have the skills and tools necessary to do so properly. But, even with that stroker crank, it seems highly odd to me that you have that level of wear in 8 hours without having some sort of major issue. I would have the cyls inspected by a shop to make sure they aren’t out of round and there isn’t anything funky going on with them then have them correct the issue.

You could continue to run it the way it is but it will only continue to get worse and you’ll end up needing to sleeves or pistons/bore faster than you should.

Seeing as these engines are stupid expensive and so are their parts I personally would fix this issue now rather than later.

You will also want to inspect your rings for any obvious damage.



As far as the cause for this wear, there could be several things to consider.

Debris left in the engine when assembled, water ingestion, over heating, being run hard before warming up, inadequate oil to fuel ratio or oil that isn’t up for the job. When you got this engine was the bore done professionally? Were the pistons and rings new? Was the engine broken in properly? Regardless if the cross hatching is gone it is an issue that should be corrected and you’ll want to try to narrow down what caused this to avoid having the same issue in another 8 hours.

I just reread the thread and you said the cases wouldn’t hold any pressure, did the engine run away on your really bad when the issue reared its head? It could’ve been running pretty lean for a while before you realized what was going on too.

First thanks for the legit reply, I really appreciate it!

I'm gna start towards the end first. When I got the motor it was brand new and to my knowledge all the machine work was done by XScream. While I didn't buy it directly from XScream i did get it from a very reputable east coast hull builder.

When I broke the motor in I ran 30:1 klotz ski craft for the first 5-10 gallons. I took it nice and easy during that time with no WOT runs and made sure I didn't stay at any 1 rpm for too long as well as keeping the runs pretty short and letting the motor cool down in between. After breaking it in I went to 45:1 klotz ski craft and still took it pretty easy for a couple tanks. Whenever I ride i always take it very easy for the first 5-10 min letting the motor warm up before i really get on it. As far as water ingestion, that should have been very limited as well since I really haven't done a ton of flipping on it yet. I am 95% sure the motor never overheated. If anything, it was overcooled in the beginning. It came with 1/2" coolant fittings on the head initially and with those i was having trouble keeping the motor temps above 130 deg f. I ended up switching to 3/8" fittings and also added a ball valve to control the flow to the motor better.

As for the case sealant issue, I never once had the motor run away from me, in fact i never really had any major issues last season. The only issue I did notice was grease starting to leak from the rear crank seal towards the end of the season. I only discovered the case sealant issue a few weeks back, when i was getting the ski ready for the season. I found a pool of oil in the bottom of the hull and that's when I pressure tested the motor and found all the leaks.

I feel you on having everything inspected and ensuring all the tolerances are good. But I don't really need to send everything out to do that. I'm actually a mechanical engineer working for the navy as a machinist so I have everything i need to do the inspection portion. The only thing i don't have is some of the more specialized engine machining equipment, as that's not something we work with and I haven't been able to convince my boss to let my buy them YET. I'm still trying though!! With that said I do have a very nice HASS VF4-SS CNC as well as several Prototrak CNC's. The reason i mentioned doing a light hone is i was considering buying either a Lisle style hone or one of the ball Flex Hones and then running it on the CNC to get the crosshatch angle perfect. The only thing holding me back is deciding on which one to go with as well as what Grit to use.

I have already inspected the Crank and it has 0.0020" of runout measured where the seals ride which isn't great but its technically the limit of the spec. As for the bore, I haven't checked the clearances yet but I did give the bore a quick inspection with the bore gauge and all my measurements are within 0.0015". I'll post up some actual measurements later this evening

 

[DylanS]

When you say it was 130* you mean on the head and cyls? How did you measure it and where? I’m more of a “put my hand on it and if it burns in about 2 seconds she’s feeling healthy” kinda guy but I do recall you’d actually be looking to be between 110-120 ish on these bigger
motors but 130 wouldn’t raise any alarms.
How did you come up with 130 being too cold? If you think two 1/2 fittings is bad you should see how many In and out lines some of these guys are running today. Hell I feed my 1200 with two 1/2 lines and have 4 3/8th going overboard from the head.
Regardless I don’t think you had a being too cold issue. What do the tops of the pistons look like?

 

[JKMike]

When you say it was 130* you mean on the head and cyls? How did you measure it and where? I’m more of a “put my hand on it and if it burns in about 2 seconds she’s feeling healthy” kinda guy but I do recall you’d actually be looking to be between 110-120 ish on these bigger
motors but 130 wouldn’t raise any alarms.
How did you come up with 130 being too cold? If you think two 1/2 fittings is bad you should see how many In and out lines some of these guys are running today. Hell I feed my 1200 with two 1/2 lines and have 4 3/8th going overboard from the head.
Regardless I don’t think you had a being too cold issue. What do the tops of the pistons look like?

Yea so the 130 was just with the little temperature stickers on the top of the head and on the side of the cylinder. Where I came up with that number I honestly don't remember exactly but I want to say that's where my SJ used to run and that's about the point when it becomes uncomfortable to leave my hand on the motor for more than a second or two. Looking back I should have probably asked what temp should these motors be run at a lot sooner. Also I wasn't saying 130 was too cold. Initially I was struggling to get the temps up to around 110ish on the stickers which Is why I went down to 2 x 3/8" outlets. I will say I was initially confused by the fact that it seemed like I was struggling to keep the motor temps up when like you said your running 4 x 3/8" dumps on your 1200.

Also, interestingly I just got a reply from XScream who I emailed those pictures this morning and was told they looked perfectly normal.

Give me a sec on the Pistons, ill go take a pic.

 

[JKMike]

Here is a shot of the top of the piston. Looks pretty rich right?

 

[DylanS]

Any pics of skirts??
Also how’s the chamfer feel on those ports?

 

[JKMike]

Here ya go. The one of the right has spent some time in the ultrasonic cleaner also.

Intake side:


Exhaust side:

 

[JKMike]

Any pics of skirts??
Also how’s the chamfer feel on those ports?

I had the same thought, it looked like the rings were catching just a little bit. The chamfers seem pretty small to me and I was considering touching them up just a bit to try and smooth out the transition. Granted I don't have a lot to compare them to. Mainly the giant ones that come from the factory on the 701 and the few pics I have been able to find on the web of aftermarket motors.

 

[kevbo]

You have to keep the combustion temps under control or run a little more piston/cylinder clearance. Jetting full throttle a little rich of peak power will usually do it. You could finish hone the cylinder and install new pistons and be in good shape for a long time.

 

[WFO Speedracer]

First thanks for the legit reply, I really appreciate it!

I'm gna start towards the end first. When I got the motor it was brand new and to my knowledge all the machine work was done by XScream. While I didn't buy it directly from XScream i did get it from a very reputable east coast hull builder.

When I broke the motor in I ran 30:1 klotz ski craft for the first 5-10 gallons. I took it nice and easy during that time with no WOT runs and made sure I didn't stay at any 1 rpm for too long as well as keeping the runs pretty short and letting the motor cool down in between. After breaking it in I went to 45:1 klotz ski craft and still took it pretty easy for a couple tanks. Whenever I ride i always take it very easy for the first 5-10 min letting the motor warm up before i really get on it. As far as water ingestion, that should have been very limited as well since I really haven't done a ton of flipping on it yet. I am 95% sure the motor never overheated. If anything, it was overcooled in the beginning. It came with 1/2" coolant fittings on the head initially and with those i was having trouble keeping the motor temps above 130 deg f. I ended up switching to 3/8" fittings and also added a ball valve to control the flow to the motor better.

As for the case sealant issue, I never once had the motor run away from me, in fact i never really had any major issues last season. The only issue I did notice was grease starting to leak from the rear crank seal towards the end of the season. I only discovered the case sealant issue a few weeks back, when i was getting the ski ready for the season. I found a pool of oil in the bottom of the hull and that's when I pressure tested the motor and found all the leaks.

I feel you on having everything inspected and ensuring all the tolerances are good. But I don't really need to send everything out to do that. I'm actually a mechanical engineer working for the navy as a machinist so I have everything i need to do the inspection portion. The only thing i don't have is some of the more specialized engine machining equipment, as that's not something we work with and I haven't been able to convince my boss to let my buy them YET. I'm still trying though!! With that said I do have a very nice HASS VF4-SS CNC as well as several Prototrak CNC's. The reason i mentioned doing a light hone is i was considering buying either a Lisle style hone or one of the ball Flex Hones and then running it on the CNC to get the crosshatch angle perfect. The only thing holding me back is deciding on which one to go with as well as what Grit to use.

I have already inspected the Crank and it has 0.00, but it is beast to check it with a dial bore gauge or 20" of runout measured where the seals ride which isn't great but its technically the limit of the spec. As for the bore, I haven't checked the clearances yet but I did give the bore a quick inspection with the bore gauge and all my measurements are within 0.0015". I'll post up some actual measurements later this evening

A dingleberry hone or as you call it ball flex hone will only mask issues instead of correct them, if you run a light pass through the cylinder with a parallel jaw hone you can usually see the high and low spots, it is still best to check the bore with a bore gauge in both X and Y axis to see if it is tapered or out of round and determine if the piston to wall clearance is still within specs.