Where do I start ? Weak 150 Merc

[Dart'nFart'n]

Where do I start ?

Any imput more than welcome, keep me on the right TRACK, as I'm a noob to a Merc 150, pretty much a Dummy, but reading lots on here and learning.

89 Astro 18 ft.(Heavy 1250 lbs)
89 2.0L 150 Merc.
21P Laser II

Wide open, 3/4 Tank and my "Lardass" 220 lbs, says 40 mph on speedo @ 5400 rpm (slight trim, just enough to come up to 53-5400, from 5000 rpm @ 39 mph)

Feels about 40 also, much slower than my I6 tower 150 on 16 ft. which can FLY ! (seems like it to me anyways)

The thing seems to run & Idle good, although ya gotta "Nail it" outa the hole to get it to go, otherwise, if ya just "ease into it" it just bogs and stalls ?

So I'm guessing I should "start", by checking Compression on the Engine, make sure "what I'm working with ?

To check Compression, what do I do ?
Remove all plugs and ground Wires ?
or
Just jump the starter to spin ?

Wide open Throttle ?
About 4 bumps per hole ?
Hot or Cold ?

Any "pointers" you guys can bestow upon a "windy" Guy ?

Thanks, Bob out.

[wrechin2]

run the engine and get warm. This will allow for the pistons to get hot and expand. remove all plugs and remove the kill lanyard. Install a water hose, this is to protect your water pump, and spin untill you get the highest reading with throttle held open. Then find someone with a leak down tester and check the leakage at about 1/2 after top dead center. Have found many high leakage engines like that. Have one now tore down with deep scratches in the wall and they don't go all the way up.

[wrechin2]

It still should push it harder than that! Need to verify it is a mechanicaly good. I will post a PDF for the link and sync for that engine. If it has a idle stabilizer I would remove it and set the max timing to 25. I did one last year and it would run close to 60!! It had a 22 trophy on it I believe.

[wrechin2]

Here is the link and sync for that engine. The year is different but the precedures are the same. Maybe the 2L king T-rex will post some useful info.

[Dart'nFart'n]

Thanks Wrechin2
I will do as you indicated for a compression test for now, until I can find a leakage tester.

Appreciate the insight !
Good thing I asked.
I NEVER would have thought about burning up the water pump !

Bob out.

[wrechin2]

Even though it would be "wet" from running. No reason to take a chance.

[Dart'nFart'n]

60 ? WOW !

Geez I'd be more than happy, if the "thing" could get going to 50 !

I'm darn sure it would NEVER get a skier up as is !

It is a pretty heavy Boat this Astro, (1250 lbs), I just bought it, and although it's mainly just for cruising and tubing/Fishing, it'd still be nice NOT to get passed by every Boston Whaler with a "Frigidaire" on the back !

Maybe I should just go get some paper bags, and cut some "eye holes" for my melon ?

Thanks again, I'm off to buy a Compression Tester FIRST !

Bob out

[grendle]

Here is the link and sync for that engine. The year is different but the precedures are the same. Maybe the 2L king T-rex will post some useful info.

What manual is that out of? I have a clymers and yours is much clearer and also different (i think) from what they say. Will that work on my xr2? Also mine says there are no adjustments on the carbs but yours says there are...humm makes me think .... Mine runs rich at idle (always has) . I need a copy of the one you have lol

[wrechin2]

Mine was a procraft!! Sorry! Still it weighed about the same. A 200 would push the astroglass to the low 70's a 150 should at least get it in the mid to high 50's! My uncle has a 88 18 astrogalss with a 2.4 200 and it runs around 73-74.

[wrechin2]

Factory manual. The link and sync is the same as far as the timing preedures. The WH carbs are all jets and are used up to around 91 and the WHM are around 91 up. carbs do have idle screws!!! That is the only thing that is going to be different. All the rest will work on the XR2.

[grendle]

Factory manual. The link and sync is the same as far as the timing preedures. The WH carbs are all jets and are used up to around 91 and the WHM are around 91 up. carbs do have idle screws!!! That is the only thing that is going to be different. All the rest will work on the XR2.


great! mine is an 87 xr2 with the dual float center bowl carbs (no designators in my manual) . Where can I get a copy of the factory manual ?

[wrechin2]

post your email or email it to me and I will see if I can send it over to you.

[Dart'nFart'n]

OK
So I've done a Compression Test, but haven't been able to find a Leak Down Tester yet.
Anyways,
All 6 holes climb to between 120-122 psi.

Am I right to assume that that is a good sign ?

From the reading I've been doing on here, I think that maybe, just maybe, there is a chance this thing "might" be able to go a little quicker than 40 mph ?

I'm gonna start reading the Link 'N Sync stuff

Thanks Again for the help Wrechin2 !

Bob out.

[wrechin2]

That is about normal. Shave the heads and that 2L will think it is alot bigger. LOL! I just built a 2.0L a few weeks ago and shaved the heads, got the compression to 148-149 and It was unreal how much stronger it was. It got a few more MPH on top also.

[shooter1]

Before you shave the heads and create the headaches associated with that get the motor running properly first. With the compression at 120 that is normal. You say it bogs coming out slow. Toss the idle stabilizer and set the timing to NO MORE THAN 25* WOT at cranking speed. Also check and make sure that the timing arm is going full travel. Motor sounds lazy to me. Make sure all cyl. are firing also. When you get the motor running properly if you are still under powered then shave the heads but be prepared to change the jets and using 92 octane gas. My experience like this is if you don't fix the problem first you will start throwing money at this motor, and if you don't believe this start throwing $100.00 bills at it and see how many it eats. Just my $.02.

Shooter1

[grendle]

post your email or email it to me and I will see if I can send it over to you.


[email protected]

or if it's a bigger file

[email protected]


Thank you :)

[grendle]

I had the idle stabilizer issue as well , the red wire was bare, frayed, and coroded UNDER the box where you couldnt see it.

[Dart'nFart'n]

OK,
PUNT the "Idle Stabilizer", I can do that,
DUH,

What's the "Idle Stabilizer" look like ?

Anybody got a reasonable description of how to find it, or locate it, by what the "Idle Stabilizer" looks like ?

It's just I don't wanna PUNT the wrong thing, and find out I threw out my "Phase Warp Convertor" LOL !

Thanks again Fellas
Bob out.

[j_martin]

OK,
PUNT the "Idle Stabilizer", I can do that,
DUH,

What's the "Idle Stabilizer" look like ?

Anybody got a reasonable description of how to find it, or locate it, by what the "Idle Stabilizer" looks like ?

It's just I don't wanna PUNT the wrong thing, and find out I threw out my "Phase Warp Convertor" LOL !

Thanks again Fellas
Bob out.


Gotta have the Phase Warp Converter, or it won't go over 33 GPS, but yer other speedo will read 87

If you look at the switchboxes, there's a jumper between the two from one of the top 4 screws. That's the bias circuit. Anything else connected to those terminals (ie, the idle stabilizer or advance module) can be safely removed and discarded. Just follow the wires.

hope it helps
John

[grendle]

It's a black rectangular box on the port side with 3 wires going to the switch box (s) (wires are red, black, and white / black stripe) get rid of it. By the manual you set the timing to 19 deg and the box advances it another 6 over 5000 rpm. Toss it and reset your timing (I set mine to 23 deg WOT) and thats pretty much it.

[grendle]

Question My advance module was PN 93772 (a1) after removing it , do I need to reset the Primary pickup timing as well as WOT? The manual says 11 deg atdc ( when I checked it was around 3 smoking and running like a dog) after taking it on the water the motor has the best whole shot around 12-14 deg atdc (dosent smoke but a little harder starting and idles low). does my old module advance the low rpm timing as well ? (some do 3 deg if i read right, if so my motor should be set around 14 without it? correct ? ) 87 merc xr2 150 thanks :) she turned 5000 rpm for the first time today :) !!!!!!

[Dart'nFart'n]

Is the "Idle Stabilizer", the Box on the port side, behind the Timing arm, that aslo has wires going to the Oil Mixer Control ?

[shooter1]

Nope that is the lube alert module. Probably right above it behind the flywheel on the port side of the motor.

Shooter1

[wrechin2]

Not all engines had the stabilizer or advance modules. If the engine is the same year it would be mounted on the top close to the port head. The earlier ones were mounted on top of the carbs. You can check the pick up timing but should not need to be adjusted. Just set max timing to 25*. The only carbs I have seen with issues were the wh-22's. They tend to stall alot when you rev lightly after the idle stabilizer was removed, then you had to adjust them. That has been my experinence. The module on the port side of the engine close to the timing arm is the oil injection module. For a reliable engine it needs to be removed and pre-mix your oil. You would also need to removed the other componets and the parts will cost you around $20. I have rebuilt many engines for the gear failure. Make sure the trigger is not dragging, but you said if you hit it all at once it would go. That is usually the opposite when a trigger is slow to advance and is ususally the wiring sheath has gotten hard and stiff or the grease is hard. It may also be as simple as the style of prop that is in it making it react like that. I ran a 22 yamaha on a modified 2.0L on a 18' ranger. Engine would pull 7K in a snap of a finger. Would climb the trailer and push all of it up the boat ramp. Put the same engine on a 18 Bass tracker with the same prop and it would stall going on the trailer. Check the link and sync and if she is health and you want more out of her, cut the heads. Best bang for the buck. I cut them alot and have yet to have some one unhappy with the results. Just remember to jet up. Last 2.0L I cut was 4 weeks ago. Cut 7CC's off and took compression to 148-149. Cut the nearly 7 seconds off the hole shot with the same set up and gained 5.7MPH gps. Went up .004 on jets and 93 octane. Do a search on the subject and make you own conclusion. Just my 2 cents worth.

[wrechin2]

grendle,
When I get a chance....I will have to post that on a website then you can download it.

[Dart'nFart'n]

Great explanation Wrechin2, thanks for taking the time to go into such great depth.
I'm off like a "terd of Fuffalo's".

My Plan;
Good look around for any Timing/Idle modules, and trace back anything connected to that Bias wire and remove.

Set Lync/Sync/Timing to 23-24, after verifying no advance/Idle Stabilizer.

Remove Oil Mix Control arm and go PRE-MIX from now on.

Go retest, and see if I can get going fast enough, to kill a bug with my windshield !

If still a "terd", I'm cutting the heads and get the psi up around 145, with an up-jet.

[j_martin]

I have seen the trigger harness strapped down, preventing the timing from advancing. The trigger harness, where it comes out from under the stator going toward the back of the engine needs to be completely free. It should be on top of all other wires and hoses, and the first strap on it should be the one that straps it along with most of the other wires to the switchbox mounting plate.

If the engine is running rough and not actually racing with the idle timing advanced, something else is wrong. (Compression, idle mix, bleed hoses, vacuum leak, carbon'd up.) Think about it, in a normal throttle advance scenario, timing advances before the throttle plates come off the stops.

Mains affect idle, floats affect everything. An idiot with a dremmel tool re-inventing the carburetor really fuddles things up.

hope it helps
John

[T-REX]

Wrong placement ov tha stator screws will hender top end time'in too....if tha screw behind tha trigger arm is too long, it will stop tha trigger from full advance'in..

[wrechin2]

Just make sure you have a healthy engine.

Just a thought......Have you verified the timing pointer?? Don't skip that part. Someone could have moved it and you THINK you are setting to 23-24 and could actually be 15*. Bettter to be low than high.

[j_martin]

Wrong placement ov tha stator screws will hender top end time'in too....if tha screw behind tha trigger arm is too long, it will stop tha trigger from full advance'in..

Been there, done that!!:eek:

[Dart'nFart'n]

YIPPEE !
Lync'Nsync worked !
I did the .462" thing too.
It appears there wasn't any Modules on this Motor, somebodies already been in there !
BUT,
The Timing was only @ 18 with no modules, so I reset to 23, now, mini Merc seems to push for all it's worth !
Comes outa the Hole OK, goes to 55-5600 rpm, but alas, still only 44 mph on speedo, but definately quicker !

This Boat pushs A LOT of water !
Comes squirting out at Drivers seat, or slightly in front of it at speed.
What a PLOW !

Next question
Currently 21P Laser II
From reading on here, and suggestions, would a Tempest type prop "lift" and get more of the "TUB" outa the water, hence more speed ?
If yes, then what Pitch can I use ?

I've still got a near "Future" Head Mill/psi increase planned, so can I stay with a 21 Pitch on a new Tempest Prop ?

Thanks again YOU GUYS for all the HELP !

Bob out.

[wrechin2]

Great to hear running better. You had the info, just had to do it. Not all had any modules. With more rpm's you will be ok. What prop to run.....that is hard to say. I have had higher pitch props turn higher rpm's due to lifting better than lower pitch props. I like choppers, trophys, tempest, ect. You may go to bass boat central and find your boat/engine combo and find a good set up. Usually someone else has done the leg work and will post prop, height, speeds, rpm's, ect. Usually you can call the boat manufacture and they will know what needs to happen.

[j_martin]

I picked up a lot of snap and speed when I repaired my waterlogged transom and floor system.

You might be hauling around a lot of water.

One clue for me is that when the transom is wet, it is also soft, and the engine doesn't trim out like a should. When your spray is beside you, yer nose ain't high enough.

just a thought.
John



YIPPEE !
Lync'Nsync worked !
I did the .462" thing too.
It appears there wasn't any Modules on this Motor, somebodies already been in there !
BUT,
The Timing was only @ 18 with no modules, so I reset to 23, now, mini Merc seems to push for all it's worth !
Comes outa the Hole OK, goes to 55-5600 rpm, but alas, still only 44 mph on speedo, but definately quicker !

This Boat pushs A LOT of water !
Comes squirting out at Drivers seat, or slightly in front of it at speed.
What a PLOW !

Next question
Currently 21P Laser II
From reading on here, and suggestions, would a Tempest type prop "lift" and get more of the "TUB" outa the water, hence more speed ?
If yes, then what Pitch can I use ?

I've still got a near "Future" Head Mill/psi increase planned, so can I stay with a 21 Pitch on a new Tempest Prop ?

Thanks again YOU GUYS for all the HELP !

Bob out.

[grendle]

Let me say this board is great , After reading and chatting and all else I have a wealth of knoweladge I didnt before. For mine , I found when attempting to adjust the timing , that half of the adjustments didnt do anything. So i got her running decent on the water (after getting comfortable with what does what )

here's what I found originally: primary was set at 6 deg, WOT was at 16 deg, cabel was too short , throttle stop improperly set , and carb linkage improperly set. it ran like a 90. (got beat by a 17ft nitro with a 115)

here's what i did : loosen everything! lol and start from scratch. Now : primary is at 11, wot is 24 deg, carbs now open fully! , linkage is aligned properly , cable adjusted correctly. Everything else looks good and is where it is supposed to be per the service manual (thanks Wrechin) I cant wait to take her out later today :) I can already hear a difference when I fired her up on the muffs, sounds snappier and dosent smoke badly anymore. :) hopefully someone can learn from my fiasco. lol

[wrechin2]

Here is the link to the manual. Download all 22 files and put in 1 folder. Open the one labeled cover and go to the bottom. If you want to look at the lower, click on that section and it will go to it.

http://www.mediafire.com/?sharekey=13fa5e8d760c466f8d78a0e5552916099c10d685b10d5b65b8eada0a1ae8665a

[grendle]

just awesome :) thanks :)

[wrechin2]

:thumbsup: