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Air silencer off

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nicknack2

Regular Contributor
"Guys, I have posted this befo

"Guys, I have posted this before but have not gotten many reasonable responses so I’m re-wording to better explain my problem... I can run my motor nicely at 4700 RPMs with the silencer on, I take it off and the motor revs up to ~5300 RPMs, why is that??? I like to be able to run at 5300 RPMs with the silencer on as it should be, the other issue is that at idle speed (on or off gear) My motor smokes a lot, once I rev up to 1000 and higher I can't see any smoke...my carbs only have orifices so I can not adjust the idle mixture my motor is a 200 hp Johnson...}"
 
"i have alot of update info fo

"i have alot of update info for ya on that 200....what year is it?........
but,to answer your question,the newer looper engines,are very dependent on the calibrated airflow thru the air silencer/breather.do NOT keep running that engine,w it off,it is running leaner,that is why the higher rpm's..,and the internals,will become externals one of these days."
 
Remember this engine was piece

Remember this engine was pieced together...he may not have the correct air silencer at all....
JWB...what are those updates? Please post them.
 
"JWB, thanks, I don't run

"JWB, thanks, I don't run the motor w/o the air silencer, I did a couple of runs w/o it just because I had installed a new bowl gasket on the bottom right carb, I guess that would be bottom port side carb, and happen to notice the RPM difference at WOT, but I’ll make sure that from now and on the silencer stays on, but what ideas do you guys have in order to get the motor to full WOT RPMs?? in reality I will hardly ever run it above 5000 RPMs since the lake I visit is small, out of the no-wake zone I only have about a ~1.5 mile loop where I can open it up, my issues is that if the motor is not reving all the way up that tells me something is wrong, I have read here in the forum that lower than usual WOT RPMs causes the motor to lug which is no good either, so that is why I'm trying to get this thing to perform at its fullest even when I’m planning to cruise at no more than 4500 RPMs, also what about the excessive smoke at idle speed??? I mix 50:1, my motor I have no idea what year is it as the serial number on the lower unit calls for 1998 200 hp Johnson, is there other serials on the power head to stablish year model???, the shape of the air silencer and the carbs (no idle screw) tells me that the power head in at its best a 1993 as that was the last year carbs had orifices IAW parts manual, however by the shape of the air silencer and the side plate cover/gasket on the right side of the carbs and again IAW parts manual it is a 1991… yeah I know what a mess… I understand that at higher altitude there is a lack of air/oxygen I’m at the lake at only 3600 ft above sea level, going with higher/ bigger idle orifice would alleviate some of the smoke??? As more air will cause a leaner condition at idle??? Would that chance my idle RPMs also??? Since my idle RPMs are already at ~750 and w/o idle screw how go I adjust idle speed????"
 
"Nicknack....
Problem: lack

"Nicknack....
Problem: lack of WOT rpms. I think maybe you are over-propped. The sure fire way to tell if your engine is running at full output, is to put a test wheel on it and run it in the water/tank. If it runs up to 5000 rpm on the test wheel, then you are probably fighting a non-issue with the motor, and it is simply over-propped. If it never makes it to 5000 rpm with the test wheel, then go back to troubleshooting the engine.

Idle speed: 750 is good, in the water with back pressure. Why are you worried about the idle speed?

Idle speed: Idle speed is not adjusted with the idle screws that your carbs do not have. Check out the book regarding adjusting idle speed. It is done with timing, not carb adjustments.

I would like to know what your compression numbers are. Don't guess at them, measure and post if you can.

You still talking to Robert? I don't see anymore EBay listings from him...."
 
"here are the updates i am awa

"here are the updates i am aware of,for the 90 degree looper 200 hp's,prior to,...98...but,i damn sure would ck to see that you have the following and a cpl i know,u wont...
1. All carbs,need #67 HS jets EXCEPT--#2 Cyl Carb-it needs a 69.There is an inherant cooling problem w/that cylinder,more fuel/more oil.
2.The Carb drain plugs,..MUST HAVE,the drain plugs w/the tits on them,..jets have come unscrewed,causing massive lean running,burning pistons up.,(I had a jet back out of my 200,had the titted plugs)
3.HS timing needs to be rduced 2 degrees.
4.Timer ring needs to be checked for looseness,as well as magnets,anytime flywheel is off,or ignition problems,or bogging,backfiring,or hard starting,is encountered.
5.Trim tab water pickup hole needs to be drilled out to 1/4 inch for more adequate cooling of propshaft bearing housing.
6.During overhaul of these blocks,there is a cooling modification,that marfab does,that greatly increases cooling to critical areas.We just this past week,overhauled a 95 200 and got to see that mod,and it is impressive.These blocks,upon continuous HS running,tends to overheat in certain areas,thereby causing a dowel pin in piston,to migrate out of piston,rings catch on ports,and ruin that cylinder.
** All my above information,has come from many reputable sources,dealers,highly trained techs that i am in communication with at dealerships,and many many online sources,such as marfab.."
 
"U do have idle adj MIXTURE sc

"U do have idle adj MIXTURE screws...,however,u adj idle SPEED,on the side,7/16 nut and a screwdriver"
 
"Thanks JWB.
On his carbs...n

"Thanks JWB.
On his carbs...no idle mixture adj screws. Fixed air orifices. That's what has him bumfuzzled.

But the marfab modification...I have heard of that, and I have actually called them. I just have a problem with this mod...no one will tell me EXACTLY what they do. And I mean exactly. It is all kinda discussed in generalities...kinda smoke and mirrors type of talking.
I asked the guy...what exactly do you do? He was vague in his answer. And I really have a problem paying someone $210.00 for a mystery modification. If they would tell me the details, I might spring for the modification.

Am I being unreasonable? You say you saw the mod, and it was impressive. What did they do?"
 
its all secret sh*&%..

its all secret sh*&%.....i am sworn to secrecy.....what if they send out the MAFIA after me or some kinda bs
 
"Your kidding!!!
Where are th

"Your kidding!!!
Where are the screws? On my 200 1996, there are mixture screws installed at the exact same location that the idle air bleeds are on HIS carbs.
You put a small screwdriver down in the hole, it passes into the plastic carb body, and adjusts a needle that is actually threaded into the throttle body aluminum plate.
On his carbs, as well as on the parts diagrams, it shows NO needle valve/screw in the location that mine is.

Remember that he is dealing with MAYBE a 1998 block, 1991 carbs...etc. We don't really know what was pieced together."
 
"they are drilling out larger

"they are drilling out larger flow areas,...and drilling directly INTO,,and under the volt/reg/rect area,..to get more water flow around the cyl's and into heads...they also r using larger water delfectors,and looks like a better material.,and cleaning up flow areas.as soon as my block ,blows,it'll be up there,as well as any others that come my way,..i just recently got set up w/them,..great people."
 
"well,...ok,...i am forgetting

"well,...ok,...i am forgetting about the piecing together thing.....let me look at it..."
 
"I knew it! NASA secrets. or

"I knew it! NASA secrets. or some such.
It's OK...I will just not have it done.
For all I know, they could simply take a die grinder, grind off a couple of edges, drill out a hole, and charge me $210.00.
I understand they want to protect their proprietary knowledge....I really do.

An addition to this...Wiseco pistons are supposed to have relocated the ring dowel pin to prevent this issue."
 
"yep.......u would be correct.

"yep.......u would be correct...91 ,no adj....sorry,i was thinking,..and looking at a 98.....so his only adj,will be idle speed on sd...
all the above mods that i had mentioned will aapply tho."
 
"yep,...we are now using wisec

"yep,...we are now using wiseco forged pistons too.!!....i really like the look of the rings,chromoly faced...."
 
"well,i would not strip your g

"well,i would not strip your good eng to have it done,but when it blows,send it up,they are a full machine shop...what eng do u have?"
 
we need to find out exactly wh

we need to find out exactly what block and heads he has...those 67 jets may be waaay wrong...
 
"ok----i believe,due to cyl hd

"ok----i believe,due to cyl hd design,the re-jetting mods would apply to-- 95-96--97.the jetting mod,would apply,to the 200's w/the 60's series jets,in the hs."
 
"I know you answer so many pos

"I know you answer so many posts, it must be hard to remember...but I am the guy that bought a 1996 200 to replace my blown 1996 200, swapped p'heads (my L/U was better) and then after all was ready to go, and running right, I put pre-mix in the starboard tank, but failed to switch to that tank, and accidentally ran on straight gas from the port tank.
Remember?

Anyway, I am now (today, just finished) tearing down this 1996 200 to see what damage I did. I am considering the Marfab mod. I just don't have the experience you have in assessing the damage...what is OK, and what is bad.
Rod damage, crank damage, etc.
I wish I had your experience."
 
"yes,doug,i do remember....goo

"yes,doug,i do remember....good thing u r here,..what one guy does'nt know,another ,prob does,etc...combined knowledge..
ok....u absolutely,..need to do the things i posted,up there,...go out and pull me,any hs jet,..i wann know what size they have in it."
 
"here is a very important lil

"here is a very important lil tidbit of info...these loopers,can be a bit confusing,in the way they fuel the cyl's...standing at the FRONT of the powerhead....u will have carb number 135 on right--246 on left...now,..walk behind eng,.top right cyl,is 135 down,top left is 246"
 
"OK...I have all the original

"OK...I have all the original carbs from that engine...I have owned it since new, so I know that there have been NO jet changes. I will go get the HS jet #s by cylinder for you tomorrow.
I know that the intake effectively crosses over...#1 carb is not in front of #1 cyl...it is opposite side. Hard to describe.

At this point I don't know what they will be, number wise, but I am gonna bet they will all be the same. Let you know tomorrow."
 
"Dough: My prop size is a 14.5

"Dough: My prop size is a 14.5 X 19,I can do about 35 MPH @4500 rpms but can't rev any higher than that, but I can feel that the motor can do better than that, last time I took the motor to the shop, the tech ran it in the dyno and said that the motor output was where it needed to be, as far as Robert it appears as if he sold the shop, some guy by the name of Alex called me after I e-mailed Robert about some issues with the motor (to be exact me trying to figure out the actual year and model of this "franky" motor) as far as compression test last test I did I can’t remember the psi number but I remember for sure that all reading were within 5 psi on all cylinders

JWB: what do you mean by this: "however,u adj idle SPEED,on the side,7/16 nut and a screwdriver"

Are you talking about adjusting the linkage???

and last what do you mean by:"so his only adj,will be idle speed on sd...""
 
"Wow...i'll be da...ed!. S

"Wow...i'll be da...ed!. Sold his shop. Wow.

I am running the same prop. I was expecting you to say 14.75 x 21 or something like that...
You know that putting a 14.5x17 on it will make it rev higher....

Your dyno guy, did the motor rev to 5500 while he was testing it? Or did it stay maxed at 4700 like you experience on the lake?
I wonder exactly what he meant by "where it needed to be"...??? Was it putting out 200 hp or not? The dyno should give exact output numbers. Not "where it needed to be" numbers.

I really want to know the comp numbers. I want to compare them to mine. I want to know if they are at or below 95psi.

I still have those carbs and butterflies....correct for a 1996-1998, with idle air bleed adj screws, got the silencer too. But those screws are NOT your problem. You say you are at 750 rpm in the water at idle. What is the problem?
But to make Franky more correct...I still have 'em."
 
"Dough, yeah he did the testin

"Dough, yeah he did the testing IAW the manual, said something like 4895 psi or pounds can remember exactly @ 5000 or 5500 rpms I remember saying that he ran it as hard as he could safely trying to replicate the problem I was having, which later I figure out that it was the glass fuel filter I had on, it was very restrictive any way I checked that 4895 # on my manual and the number were good, my compression test I want to say that it was in high 80s and I mention that to Robert but I remember Robert saying that my power head was a low compression power head so that even right out of the factory my motor put out only 90psi...

the problem with 750 rpms is that it grinds a little hard when going in to gear, out of gear it idles higher than 750 maybe ~900s and the motor shakes and smokes too, I just trying to tune it better at idle and maybe the shaking and smoking will go away."
 
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