Procedure for compression test on 4tech?

[Carboncow]

Seller accepted my offer on a 2008 SDC 180. Done many a compression test in my past and even on some old two stroke rotax.

Looking for a procedure and/or anything unique to this engine?

I seem to recall with the older rotate I had there were little metal hangers on the engine to attach the spark plug wire to for grounding...as not to damage something (ECM box or such?)

Did some googling on the site but just lots of thread on what the values should be.

 

[Coastiejoe]

Cold engine, all plugs pulled, throttle held to FULL THROTTLE position. This causes a no spark situation.

 

[Carboncow]

Cold engine, all plugs pulled, throttle held to FULL THROTTLE position. This causes a no spark situation.

Oh that's slick and easy!

Going to hijack my own thread...does anyone every pressure test the closed cooling system?

 

[Coastiejoe]

I have done so on HUNDREDS of vehicles, but never had a need to do so on a ski. That said, if you have a leak, it is a viable test. If you had an internal leak, you can normally tell from the spark plugs as they will be steamed cleaned..

 

[Carboncow]

I have done so on HUNDREDS of vehicles, but never had a need to do so on a ski. That said, if you have a leak, it is a viable test. If you had an internal leak, you can normally tell from the spark plugs as they will be steamed cleaned..

Thanks Joe! I've reading a couple hundred forum posts over the last month and saw nobody having issues with the cooling or testing...but wanted to know if anyone does their due diligence.

The guy owned it for one summer, owns a motor cycle shop and I won't get to test drive it. So my DIY survey is all on land. Checking prop, wear ring and compression. Anything else you suggestion. I am familiar with the ceramic washer and will be pulling SC before boat hits the water...it had 80 hours.

EDIT: Steam clean...got to remember that! Seen it with cars but would forgot to question plugs that are too clean! I know he hasn't changed them.

 

[Coastiejoe]

If you can't ride and drive,, then your visual and tests are very important. If it is SPOTLESS as in it just got detailed, then it makes it hard to make a good determination. If the inside hull is nice and clean but not detailed, that is a good sign. My skis are always clean on the inside. I use a power washer inside and out after every ride. If it looks like an oil mess, it normally means it was ridden but not taken care of.

SO,, you are looking for a good happy medium. You want it clean to show that they cared, but not detailed as that is often a means to hide things..

 

[Carboncow]

They haven't done anything to make this ride pretty. They didn't have the towing canvas so it was full of debris although warm stored in the winter of their cycle shop. Since they haven't tried to clean it...we can assume what you see is what you get and the bilge and engine look OK to me for the year/hours. Will update with questions after my survey tomorrow. Thanks again.

 

[Coastiejoe]

Best of luck with it, hope it all goes well for you...

 

[Carboncow]

Best of luck with it, hope it all goes well for you...

Deal is done on boat...will pick up next week. 2007 180 SE with 85hrs for $9800 with trailer.

Compression tests showed:

1: 135lbs
2. 133lbs
3. 134bs

Prop was stainless (is the factory stainless?) and looked brand new...not a single nick on the leading edges as a I looked through the intake and as much as I could see in the exhaust. It was winterized by a guy who knew boats...but nothing 4techs that much. bought it from a used motorcycle shop that I think took it in from an auction last fall.

Everything shifted fine and linkages were clean and smooth. It was a dirty boat (but not nicked up) and the engine compartment was a little dirtier then I liked. Oil was full and looked clean. Started on first hit of the button.

Question...

1. I could only run the boat about 2-3 minutes (I've read you can usually run these 5-6 minutes) before the exhaust got hot and threw a code on the dash, so I shut it down. During that time the idle only dropped from approx. 2400 to 1800.

2. Does it go down lower once it warms more or is under load...what is normal idle for these?

Supercharge will be pulled the next week and sent off for rebuild. Anything else I should do other then a oil change and/plugs?

 

[Coastiejoe]

It should only be run for a minute when out of the water. On the hose or off the hose, still one minute. Out of water there is no load and the idle will be higher. Being a 4-tech, there is a chance that the electronics will adjust this down a bit. I do not know if all boats were stainless impellers, but both of my skis were/are.

 

[Coastiejoe]

If you are not familiar with the Carbon Seal, become familiar with it. It is why you should not run the boat out of the water for more than a minute and it is a VERY important part as if it fails, the boat can sink quickly..

 

[Carboncow]

If you are not familiar with the Carbon Seal, become familiar with it. It is why you should not run the boat out of the water for more than a minute and it is a VERY important part as if it fails, the boat can sink quickly..

Will read up on the C-seal. Odd that I read a couple posts saying you can run them for a few more minutes due to the closed cooling of the engine...but I do understand the riser is fresh water cooled.

 

[Coastiejoe]

The closed loop cooling has NOTHING to do with the Carbon Seal (CS). And,,, the closed loop coolant gets cooled by the water you are riding on via the ride plate that is bolted onto the bottom of the boat... So,,, there is NO cooling when running on a hose. Further, when on the hose it is a FLUSH, which means the water runs in reverse. Yes, many places say it is ok to run it for 3-5 minutes. However, if you have a need to run it that long, you need to be in the water as at that time frame, the engine is getting hot.

The RAW WATER (Water the boat is sitting on) touches only the impeller and exhaust and the intercooler on Super Charged (SC) skis/boats. The closed loop does all the cooling. But it needs to be cooled via the ride plate. So the FLUSH is important as it runs water in the opposite direction to FLUSH things out that may have been thrust into the passages. Also, it flushes out the salt water that touched the exhaust and intercooler.

You will LOVE the 4-tech engine, very good design.

 

[Carboncow]

Great intel!. Thank you so much. Wish I would have asked questions about how long to test boat yesterday when bugging you!

I just read several posts on here about the Carbon Seal. This is only a concern when the boat is in gear as it involves the shaft, correct? Didn't really put in gear while running so hoping no damage done!

Does the ride plate actually have coolant running through it? I just found a 4 tech PDF manual online so will be reading a lot on that tonight!

 

[Carboncow]

Also...

Not seeing this info but has anyone made/hacked a OBD2 type code puller for the 4 tec? I know in the world of Vw we have a VCDS and Volvo has the Vida Dice.

Could we be so lucky for any type of 3rd party programmer/code puller?

 

[Coastiejoe]

I'm sure you did no harm,,,

Unless the 4-tech boats are different than the skis, and I'm very sure they are not, then ANYTIME the engine is on the shaft is spinning.

Yes, the ride plate has the closed loop coolant running through it. It is basically a heat exchanger. As it runs through the ride plate, the heat is pulled from it via the raw water being colder than the coolant water..

Putting the boat in gear simply moves the bucket in the rear. In the full down it would be reveres, in the middle it would be neutral, full up it would be forward...

 

[Carboncow]

Putting the boat in gear simply moves the bucket in the rear. In the full down it would be reveres, in the middle it would be neutral, full up it would be forward...

:face palm: I should have known that...boo on me!

 

[Coastiejoe]

It is a learning process... I can not tell you all I have learned by joining this site. I was a member for some time before I was asked to help Moderate. I think for me, it was my ability to be on the site often and how I handle people more so than the knowledge I had.. LOL I am still learning... Every day..

 

[Carboncow]

I appreciate your patience and desire to help. I work in IT and have moderated a few auto forums over the years and the impatience and attitudes on many are terrible. Lucky for most of the boating world I'm in there is a strong desire to help, and patience.

 

[Coastiejoe]

There are other Sea Doo sites, but no where like this place as far as how people are treated. No comparison... I bet I am here 75 times a day just looking things over and proof reading...

 

[Carboncow]

wow, way more dedicated then I ever was helping! I actually invited some young tools on these sea doo forums...but not really seen it yet. In the Vw world there are far to many know-it-all 20 somethings ready to pounce on newbies because they don't use the search or the question has been asked 1001 times.

Glad I'm here!

Plus I actually saved two Sea Doo hats from 15+ years ago when I had my GTXs. They are total vintage now so I can wear them again and not embarrass the family...I think.

 

[ski-d00]

4tecs should only be run 15 seconds or so w/o water, you can trigger the exhaust temp sensor in much less than a minute and the exhaust manifold will be red hot which is not good considering it doesn't even use a gasket and relies on flat surfaces to seal.

If on the hose, you can run them 3-4 minutes which is the limit for the carbon seal. On rare occasions, I've used another hose on the inside of the hull on the carbon seal for cooling. make sure you pull the plugs, lol.

boats are exactly the same as the skis with regards to driveshaft, pump, etc. but many like the twin engines don't use the ride plates for the cooling like the skis, they have separate larger heat exchangers on the bottom side of the boat.

compression check is better for 2 strokes and is fine on 4tecs but a better test is an engine leak down test for the 4tecs for engine health.