Help plz. 87 Mercury 150 xr2 Black Max

[Bassnailer]

OnTrak's advice is spot on. I had a 2.0 XR2 for many years, and it was a runner. You will need to remove the boxes permanently. Get a good service manual to make sure you are removing the right things, but they are about the size of a deck of cards and it's on the top of the motor behind the flywheel. The idle boxes do two things, 1. They advance the timing some at idle as needed to help the motor idle smooth, and 2. They pull timing out of the motor as you approach 6,000 RPM, which limits your power and prevents you from ever getting to 6,000 RPM. As pointed out, the XR2 doesn't make a ton of low end torque, but makes good power on the top end. The reason for removing the idle boxes and setting the timing to 23 degrees is so you can prop it with a a good prop for hole shot (a little less pitch) to help with that limited low end and turn the propellor faster taking advantage of the XR2s power in the 5800-6200 RPM range. When I had my XR2, I turned a 22 inch 4 blade prop up to around 6200 RPM, which gave me great hole shot and still ran a good 58 mph. 23 degrees of timing is plenty safe on pump gas, and you won't really notice any difference in the idle quality. Plus, it's one less thing to go bad and cause you problems. Good luck, those are great little motors, I ran mine for 15 good years before finally selling it and moving up to a 200.

[Unkl L]

OnTrak's advice is spot on. I had a 2.0 XR2 for many years, and it was a runner. You will need to remove the boxes permanently. Get a good service manual to make sure you are removing the right things, but they are about the size of a deck of cards and it's on the top of the motor behind the flywheel. The idle boxes do two things, 1. They advance the timing some at idle as needed to help the motor idle smooth, and 2. They pull timing out of the motor as you approach 6,000 RPM, which limits your power and prevents you from ever getting to 6,000 RPM. As pointed out, the XR2 doesn't make a ton of low end torque, but makes good power on the top end. The reason for removing the idle boxes and setting the timing to 23 degrees is so you can prop it with a a good prop for hole shot (a little less pitch) to help with that limited low end and turn the propellor faster taking advantage of the XR2s power in the 5800-6200 RPM range. When I had my XR2, I turned a 22 inch 4 blade prop up to around 6200 RPM, which gave me great hole shot and still ran a good 58 mph. 23 degrees of timing is plenty safe on pump gas, and you won't really notice any difference in the idle quality. Plus, it's one less thing to go bad and cause you problems. Good luck, those are great little motors, I ran mine for 15 good years before finally selling it and moving up to a 200.

Ok thanks for the help. Yall have all giving me good input. gonna be a busy bee Sunday doing all this. Hope it all comes together. not looking for a rocket ship. But definitely looking for 55 plus mph.

[Jonestrollingmotor]

Get the mercury service manual and will lead you in steps. Basically, the path is the stator feeds two switch boxes, each switch box controls 3 coils. Seems like I had to have access to a meter other than a DVM meter. Also, a friend of mine (he's a certified mercury mechanic) told me if you change a switch box be sure to change both. the bias between the two needs to be equal or the old switch box will go bad and you will chase them one at a time. What this mechanic told me was that when under a load, a bad switch box will break down.
John

[Bassmeister]

I know it's not apples to apples, but I had a 2.0 135hp merc on a 17' Basscat Caracal (heavier than the Hydrasport). 2:1 gear case on a 1989 model years. I could turn a 22 LaserII 5800 at a top speed in the lower 60's. That being said, when it would get to be a "Dog" out of the hole (happened twice) I found I had a bad switch box. Once out of the hole, it would cut my rpms down to around 5K. I agree with others, you should be able to turn a 22/23 on that motor/boat combination. As said above, I would also have the carbs cleaned and sync/link adjusted correctly.
John

I'm with John....

[OnTRAK]

When you get it running right, you should hit 55+ on that Hydra Sport hull if it's in good shape. I run about 55 gps fishing with a partner who typically brings an excessive amount of tackle and hit about 58 - 59 gps at WOT fishing by myself. The little 2.0's love running in the 5800-6000 rpm range. Keep us updated.

[Unkl L]

When you get it running right, you should hit 55+ on that Hydra Sport hull if it's in good shape. I run about 55 gps fishing with a partner who typically brings an excessive amount of tackle and hit about 58 - 59 gps at WOT fishing by myself. The little 2.0's love running in the 5800-6000 rpm range. Keep us updated.

I will it will be Monday before I go run it. Will have everything but the switch boxes done. If all that dont fix it then I will order the switch boxes. Thanks for everyone's help.

[Unkl L]

When you get it running right, you should hit 55+ on that Hydra Sport hull if it's in good shape. I run about 55 gps fishing with a partner who typically brings an excessive amount of tackle and hit about 58 - 59 gps at WOT fishing by myself. The little 2.0's love running in the 5800-6000 rpm range. Keep us updated.

Just an update. didnt get to work on boat today ended up spending 6 hrs doing a 30 min brake job on sons truck. Hopefully will get on it first thing in the morning

[pops slowdog]

Unkl L as others here say, that motor is best at 6k rpm. I ran my ‘85 XR2 for many years with an early year Turbo prop and a Merc Big Ear chopper-both 24 “ pitch. 6000-6200 rpm; my Mercury operators manual says prop it to run 6000 max. When in good condition your boat and motor would run a little faster than my 1985 champion 17’6”. This is from my experience back in the day.

I can only shade tree mechanic so can’t really offer much info on why your performance is down, but the condition of the hull can have a lot to do with it also. Good luck.

[RangerAce]

Mine will spin a 25” Laser to 6200 and a 25” Tempest plus to 6000. It’s always been a healthy motor. Hope it stays that way. The 340 is just a hair over 1000 lbs. though.

[Unkl L]

Just an update. Deleted the idle stabilizer the red wire going into the back was broke in half and rotted. the timing was off on both ends was 6° at cranking and was about 19° at max. Rebuilt fuel pump was missing a gasket in the middle. Got it all together after little lunch gonna run it on muffs then head to the lake.

[Unkl L]

When you get it running right, you should hit 55+ on that Hydra Sport hull if it's in good shape. I run about 55 gps fishing with a partner who typically brings an excessive amount of tackle and hit about 58 - 59 gps at WOT fishing by myself. The little 2.0's love running in the 5800-6000 rpm range. Keep us updated.

On TRAK I did the link and sync adjusted timing got the throttle primary at 11° ATDC got max timing at 22° BTDC. Took the idle stabilizer completely off. It was three wires a red wire a black ground and a white/black. Only took wires off the first switch box. Did not take wires running from first switch box to switch box behind it. I rebuilt fuel pump. When I took it to lake it was hard to start. Once it started it didnt want to idle to well had it moments. I could now turn 6000 rpms but did not gain any mph. Still runs 48mph on GPS. It is still real sluggish out the hole. Have to ease on throttle and let it catch up and then I can lay into it. I did check timing Mark's with a dial caliper and got it exactly on .462. Any more ideas on what to do. I premix my gas. 90 Oct non ethanol 50:1.

[OnTRAK]

The "Throttle Pickup" (idle) timing of 11*ATDC in the manual is more of a guide to get you started. With the motor warmed up, running in gear, and in the water, (you can do it on the trailer, just be sure your prop clears the ramp) gradually advance throttle primary (idle) timing until it idles smooth in the 600-700 rpm range. You will probably end up somewhere in the 6*-0* ATDC range. I think mine is at about 6*. It doesn't matter exactly where it ends up, as long as it is idling smooth & happy. You don't need to use a timing light to do this. Make sure you have the 1/8" gap between the throttle cam and the throttle stop screw boss. You can increase this gap slightly in order for the motor to have a little more advance timing come in before the carbs start to open up. This may help some with your hole shot sluggishness. To start it level the motor, pump the bulb until firm, turn the key to the start position (but don't engage the starter) push the key in and hold it for 15-20 seconds. This engages the enrichener and will prime the carbs properly. I do this even before I launch my boat. Now turn the key to start the motor pushing the key in if needed to add a little more fuel to the carbs. I learned this starting procedure here, and mine now starts real easy. The 2.0's can be a little cold natured when starting. If you're turning 6000 rpm and still running 48 GPS, you might want to check your prop for a spun slipping hub, start testing other props (your prop may have lost pitch or cup or both over time), and work on your motor height (prop to pad) set up. Sounds like you're getting there!

[Unkl L]

Thanks for the info will do that probably tomorrow. So your pretty much setting primary timing by ear.

[Unkl L]

The "Throttle Pickup" (idle) timing of 11*ATDC in the manual is more of a guide to get you started. With the motor warmed up, running in gear, and in the water, (you can do it on the trailer, just be sure your prop clears the ramp) gradually advance throttle primary (idle) timing until it idles smooth in the 600-700 rpm range. You will probably end up somewhere in the 6*-0* ATDC range. I think mine is at about 6*. It doesn't matter exactly where it ends up, as long as it is idling smooth & happy. You don't need to use a timing light to do this. Make sure you have the 1/8" gap between the throttle cam and the throttle stop screw boss. You can increase this gap slightly in order for the motor to have a little more advance timing come in before the carbs start to open up. This may help some with your hole shot sluggishness. To start it level the motor, pump the bulb until firm, turn the key to the start position (but don't engage the starter) push the key in and hold it for 15-20 seconds. This engages the enrichener and will prime the carbs properly. I do this even before I launch my boat. Now turn the key to start the motor pushing the key in if needed to add a little more fuel to the carbs. I learned this starting procedure here, and mine now starts real easy. The 2.0's can be a little cold natured when starting. If you're turning 6000 rpm and still running 48 GPS, you might want to check your prop for a spun slipping hub, start testing other props (your prop may have lost pitch or cup or both over time), and work on your motor height (prop to pad) set up. Sounds like you're getting there!

Where in reference to this photo are u referring to getting the 8th in gap how do I increase the gap to get it there. Thanks in advance 20190626_173821.jpg

[OnTRAK]

It's a little hard to describe in your photo. I'm describing it in relation to your photo which is sideways. The throttle cam is a little right and below the center of your photo, to the right of the bleed lines and sort of behind the throttle stop screw. It has a pointed end pointing slightly upward to the left. A little above it and sticking out from the motor is a solid sort of square block, the throttle stop screw boss. You want 1/8 in. of clearance between the upper curved side of the pointy part of the throttle cam and the throttle stop screw boss. Now that that's clear, this comes out of the manual. "Remove the throttle cable barrel from the barrel retainer on cable mounting bracket and adjust the idle stop screw so that the bottom edge of the throttle cam is 1/8" from the front corner of the throttle stop screw boss." When you get the gap set, retighten the lock nut on the idle stop screw. This procedure should be in your manual in the "Timing/Synchronizing/Adjusting" section you used to set your timing and sync your carbs. Try it with the 1/8" gap to start if it wasn't set right to begin with. You can try increasing the gap a little if needed to allow a little more advance timing to come in before the carbs begin to open. This may help eliminate some of the sluggishness of the hole shot. Hope this helped!

[Unkl L]

It's a little hard to describe in your photo. I'm describing it in relation to your photo which is sideways. The throttle cam is a little right and below the center of your photo, to the right of the bleed lines and sort of behind the throttle stop screw. It has a pointed end pointing slightly upward to the left. A little above it and sticking out from the motor is a solid sort of square block, the throttle stop screw boss. You want 1/8 in. of clearance between the upper curved side of the pointy part of the throttle cam and the throttle stop screw boss. Now that that's clear, this comes out of the manual. "Remove the throttle cable barrel from the barrel retainer on cable mounting bracket and adjust the idle stop screw so that the bottom edge of the throttle cam is 1/8" from the front corner of the throttle stop screw boss." When you get the gap set, retighten the lock nut on the idle stop screw. This procedure should be in your manual in the "Timing/Synchronizing/Adjusting" section you used to set your timing and sync your carbs. Try it with the 1/8" gap to start if it wasn't set right to begin with. You can try increasing the gap a little if needed to allow a little more advance timing to come in before the carbs begin to open. This may help eliminate some of the sluggishness of the hole shot. Hope this helped!

20190626_223513.jpg so at the red or the blue mark is where I'm looking for 8th gap?

[OnTRAK]

The red mark. Your red mark is on the left side of the throttle cam. You want the 1/8" gap between the right side of the throttle cam and the upper left corner of the throttle stop screw boss (the solid square piece that protrudes from the motor). It appears in the photo that you have almost no gap there now. Setting it to the factory 1/8" spec is probably all you are going to need. I have mine set to 1/8". The idle stop screw is the one just in front of your red mark. This gap should have been set before checking/adjusting your timing.

[Unkl L]

10 4 I got ya thanks.

[Unkl L]

Ok done everything I've said. I've lync and sync rebuilt fuel pump new impeller run seafoam through fuel. Boat is still low on rpms 5500 and still only running 48mph. Boat is real sluggish out hole. It's like it takes it a min to start getting fuel is best way I can put it. As matter fact idling yesterday to a spot 100yrds away as I was idling boat started gaining rpms with throttle in same position.

[apenland01]

Silly question, but did you wash the air filter/foam inside the cowling? My dad's 1993 Black Max would get dirty from sucking in all the oily smoke it was putting out at startup and he had to pull it out and wash it dawn dish soap water at least once a year. It would get slow to start, bad hole shot and couldn't get to WOT when it was dirty. That damn motor would run like new after he washed the foam air filter. Just a thought of something simple since you just bought it.