Another sad Christmas story

"Guys took the boat to the tec

"Guys took the boat to the tech, put it on the Dyno, got 3500 PSIs at 4200 RPMs, then ran it at 5000 RPMs and only got 2500 PSIs, WOT timing was on the dot at 16 BTDC, conducted a leak down test and he said that the motor was holding about 12 PSIs, as a diagnostic he said "your motor is tired" that is why it won't rev up any higher than 4500 RPMs on the water, no compression… I guess I’m due for a rebuilt…I guess the nightmare continues… or I could just burn it down… any ideas? Any tricks?"

"A pity you did not run a comp

"A pity you did not run a complete curve with 100-200 interval from 3500 to 5500.
Did he use the back-pressure device/silencer when running or just 'free' exhaust?
Which heads do you have on?
If the low-comp 185 heads the readings seems correct, but I do not have the book anymore."

"The motor was in a small tank

"The motor was in a small tank, w/o the prop, he had to stop after reaching RPMs and taking the PSIs in order to refill the tank, so it was on the Dyno for about 30 seconds at the time...that did not seem right... He said he would not risk blowing the motor, I'll take a head off tomorrow and picture it, so u guys can tell what they are, as far as I know they are low compression heads, but this is a "200 hp" motor, as far as doing the 100-200 increments well as I said the motor was on the Dyno for about 30-45 seconds at the time due to his fear to blow the motor... could stuck rings give erratic PSI readings???"

"Indoor or outdoor?
Sure no e

"Indoor or outdoor?
Sure no exhaust was entering the carbs?
Running indoor I normally had to use compressed air to get the exhaust away from the air intakes.
You do not blow the engine by running at a dyno, but have to be carefully that the lower unit gets proper cooling!!
Afraid your 'dyno-man' may not have been quite up to it.
Looking forward to the picks."

"was done outdoors, I'm su

"was done outdoors, I'm sure the carbs were getting air only, and yeah he was worried about the cooling, and as u said the dyno could have been performed in better manner, but the leak down don't lie right???"

Leak down test on a 2-stroke?

Leak down test on a 2-stroke?
You must be joking!!!!!

enlight me Morten

enlight me Morten

"nicknack, Man,everything you&

"nicknack, Man,everything you've told about your 200 is identical to what I have been experiencing with mine! I put a new power pack on, a new stator ( running goo down the bottom of it), didn't help any, and redid lync & sync, set wot timing, new fuel filter, plugs,plug wires,ck water flow & impeller, cleaned all the jets, ck all carbs & fuel lines to carbs 40 THOUSAND TIMES!!! & i don't remember what all else & finally gave up & took it fishing 3 times this past month. It has always smoked for 10 years. All my buddies give me hell about fogging for mosquitoes. BUT.... at least I'm out there using it instead of sitting in my recliner looking at it sitting in my driveway. Sometimes I get really frustrated trying to keep it running, screwed up idling, misfires, sneezing,coughing, and eventually dying but I just baby it and finally get it started again & go on. I'm going to ck more closely for loose clamps in my fuel lines next & then go to the fuelscreen on the pickup tube, maybe find some larger fuel lines,etc....? I can't get my idle timing exact with the thing running the way it does , so I guess I'll make sure my fuel system is right first. It has been a long drawn out process, so I can relate with you perfectly. Maybe we can come to a conclussion before long. If I can get mine to run right I'll let you know what I've done. I sincerely hope you get yours running the way you want it. If your wife is anything like mine, she is ready for you to get it right and get the hell out of here!! good luck, jeff"

"Oh yeah, mine is a '91 20

"Oh yeah, mine is a '91 200 hp xp ve200sleid at least I think it is, my plate was gone too. By looking at all the pics online &when I buy new parts for that # they fit & work ok. I've always loved my motor until this past year now I've been trying to figure out how it can have an accident without me being injured at the same time! ha"

"'enlight me Morten'

"'enlight me Morten'
You have mainly 2 methods of determining engine compression and compression 'leak'.
The normal and 1st choice is the compression test which gives a rough compression pressure at a 'dynamic' engine. In short engine is rotating at close to idle speed. For a 2-stroke with no valves but 'ports' it will give an indication of internal engine/cyl/ring condition from ports and up. Most important in general is that difference between cyl's should be within about 10% of each other. The actual reading may vary depending on cranking speed, hot/cold and for V-engines stb and port side.( Up to 10% less on port side).
The leak down test is a static test where internal engine parts are not moving. On an engine with vertical pistons or close to (V-engines) it may be a good second test if the comp test fails. If correct done, it might help determine if the leak (lack of compression) might be caused by valves, head-gasket or simple 'blow-by' of piston rings. This test should be performed with pistons both at top and at bottom! This is not possible at a 2-stroke, and the 2-stroke has no valves. Then as no outboards has a closed cooling system, determining a head gasket leak might be difficult, unless it is really BIG.
In my opinion, a leak down test on an outboard is a waste of time and money.
Do a comp test, and if low, rip the heads of and check visually if rings are stuck or gasket blown."

"Went to the lake today, tried

"Went to the lake today, tried couple of things and this is what I got… I bought some of that Amsoil Saber 100:1 mix which claims that due to their advanced synthetic formula that is all you need (a 100:1 mix), allowing you to mix a leaner fuel mixture to minimize smoke and still have the needed protection… well took the air silencer off as at one point in the past I was able to rev up to 5000 RPMs w/o it and it did… I was more than amazed, well I figure I take a look at the plugs, plugs were black and bone dried… probably no a good sign… well I figure I put the air silencer on and see what the motor does… installed the air silencer and I ran the motor probably for about a mile at around 5000 RPMs once again I was more than surprised, pull the plugs off and they were still dry and black… this thing ran too good to be true…I really don’t like the idea of the 100:1 ration even as it is endorsed by Amsoil which is a really good oil company and pioneer of synthetics…nevertheless the motor ran better than it ever ran before… I’m leaning towards the idea of changing the high speed jets for smaller ones (got 62Ds right now) to alleviate the running rich issue and then go back to the 50:1 ratio, I’m thinking that the motor is just getting flooded at WOT and not allowing it to rev up to the full RPM range… ideas????

Here is the link to Amsoil’s Saber 100:1 outboard oil

http://www.mysyntheticmotoroil.com/amsoil-products/2cycle-motor/synthetic-2-cycl eoil/

What u guys think???"

"Quite honest and perhaps a bi

"Quite honest and perhaps a bit rude:
You have no idea what is going on in your engine, and possibly not even sure of which engine you have.
(ref low comp heads).
I can only wish you luck."

you are right... but can you t

you are right... but can you think of an explanation for the way the motor acts with the changes I tried yesterday??? wouldn't flooding at WOT would make the motor act in that manner???

"I do not think the change to

"I do not think the change to Amsoil has anything to do with it.
Going 100:1 will reduce smoke and plug fouling at idle, but not explain the power increase from running at the dyno.
Something else is playing a part, but has to be carefully done and analyzed with proper procedure when the fault is there."

"What about flooding at WOT, b

"What about flooding at WOT, because of big high speed jets, I'm even starting to think that the motor is not a 200 hp, but an smaller motor and the 62 jets are too big and are flodding the motor...I think a leaner mixure either via the 100:1 mix or the more air coming in to the motor w/o the silencer(making the fuel mix leaner) is part of what makes the motor run good, but neither of those "fixes" give me peace of mind
neither I feel good doing it, but seem like a common factor which is making this thing run right, I dont think bad electonics/timing being off would let me run at 5000 RPMs almost want to say really good but too good to be true..."

"If you have the 'low comp

"If you have the 'low comp' heads, you got a 185 and need to be jetted accordingly, then comes the altitude correction on top. However then even carbs and valve housings have to be to specs.
Which heads do you have?????"

"You guys are probably going t

"You guys are probably going to shoot me…on my last two outings to the lake this happened…
I bought the 100:1 Amsoil Saber and ran it at 100:1 as indicated by the bottle, ran great, however; I did not feel safe about running such a lean mixture, then went back to 50:1 mixture (using same oil the Amsoil oil) and the motor reved up to 5000 rpms at WOT something the motor had never done for me, but I notice that in the last part of the throttle right before WOT the motor would kind of bog down a little, like if it was running too rich, but I was happy, I finally had this thing running good at WOT, went back to the parts books and notice that some of the 200 HP from 1991 (to which I have narrowed down my year model) did come with 56D HS jets(I had 62Ds), so I bought 6 of the 56Ds and installed them, today I went to the lake and I ran the motor at 5400 RPMs at WOT getting 42 MPHs, running very good and the spark plugs looked dry with nice tan in color on them.
Now what was the problem with this thing???? Does synthetic oil actually makes that much of a difference in performance??? (I used to run just regular cheap TWC-2/3 Wal-Mart, Pennzoil or Chevron
2 stroke oil)
What about the HS jets??? Were those 62Ds just chocking my motor at WOT???
I have heard of some 200HPs actually running 67Ds…but this one runs good with the 56Ds…
Now how can I make sure I’m not running too lean with the 56D????
What color in the spark plugs would indicate a too lean running engine???"

"If the plug insulator is choc

"If the plug insulator is chocolate brown you are good to go. If they're white, it's too lean. Also, shine a flashlight in the sparkplug hole. If the piston top isn't dark, you're probably too lean. My 150 has the Outboard Marine logo in the center of the piston. If I can't make that out it's time for a de-carb.

As far as oil, I switched to XD50 from XD30 and noticed a smoother idle and less smoke. The compression steadily improved on that motor probably due to the carbon reducing additives. At power I really didn't notice a big difference. It seems to start easier, but that can be attributed to me using the boat more."

My friend be careful, post pictures of those plugs, and verify your actual running engine temperature and post it, 56D on a 200 HP at WOT = trouble, then again if you are have boy**# reeds this will make perfect sense !

Thanks man, can you tell my how that particular type of reeds would make such a difference...for some of the 1991 200hp motors they came with 54D, I know every one thinks that any 200 hp should have 67Ds but what can I do, with 62D my motor ran rich, I'm going to the lake on Monday and will post pictures of the plugs shutting the motor off right after running at WOT so u guys can see them

How is that engine running? In regards to the reeds question if you have Boysen Reeds installed, because of its patented two stage design requires you to drop your idle jets down 4 sizes ...