Merc 1150 Won't accelerate, Starts & Idles great.

[sarconastic]

I have a '72 Merc 1150 that starts good, idles great but will not accelerate. It will rev the engine with the warm up lever some. But when you put it in gear, you have to run the throttle full forward and you get the boat moving just enough to create a wake. It's not even trying, doesn't bog, seems to run pretty smooth. I tried pumping on the primer bulb, thinking maybe fuel pump wasn't pumping, it kind of made the motor bog just a tiny bit. didn't hesitate or anything but it did slow it a little. I don't have a tac, but it would guess it's not getting over 1200 RPM's at the best.<br /><br />I haven't check the compression yet but will do so tommorrow. We just got back from a very dissapointing day at the lake. Hauled everything 60 miles there and no water sports today aside from swimming at the beach.<br /><br />I know the fuel is good, the tank was completely empty. Good oil mix. We ran it at that speed accross the lake to the local marina, got the Mechanic there to come out a take a peek at it, and without starting it immediatley starting talking dropped cylinders. While he's looking I inpect things little more, I was wondeing if the throttle linkage and everything was working. and it is. The butter flys are opening fully, the dist. is advancing. Both forward and reverse, all things seems to be mechanically moving. the choke flaps are open when not choked and working fine when activated. I checked the spark here at home prior to leaving while getting it started, it appears fine.<br /><br />I have read through the forum a lot and carbs seem to be the idea, but was wondering if it could be stuck reeds, just need to clean jets or am I am I going to get some experience rebuilding mercury carbeurators? Just one side note the boat was sitting 3 years prior to my aquiring it and spending the last two weeks getting it going again.<br /><br />Thanks<br />Sarc.

 

[wrenchtrnr72]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

if all your throttle linkage is working the right way, and your carbs are ok, you might want to check your charging system, if that is ok, than you have a timing problem. i do not have those specs, but someone on here i'm sure has them.

 

[sarconastic]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

WHats the procedure for checking the timing on this motor? I have a manual coming but it will be a week before I get it. I read somehwere about the timing being set at 23 deg BTC but would appreciate a procedure from anyone.<br /><br />Thanks<br /><br />Sarc.

 

[Chris1956]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

Sarconastic, If your compression is balanced and at least 100 PSI each, it is likely your issue is severly gummed up carbs. I would also check spark with a timing light to see that all cylinders have some, but would not make any changes until the manual arrives, and you understand the procedure. Also you can look for the spark plug leads arcing to ground, and perhaps fouled plugs. Replace as necessary.

 

[sarconastic]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

CHris thanks for the reply. The compression is good on all Cylinders, Within 3 PSI across the board. All cylinders have spark, Didn't think to use a timing light, duh, do it on a car all the time. Did it the old fashioned way. layin the plug against the block and tryin not to get too close.<br /><br />It's looking more and more like gummed carbs all the time. <br /><br />Next question, am I looking at buyin 3 kits or can I just blow the plugged ports out with Air/Carb cleaner? I have read about the seamfoam soak using a gallon can etc. running and leaving overnight. Is this going to be enough or am I looking at a complete carb rebuild?<br /><br />Also whats a fair price for carb kits for these?<br /><br />Thanks<br /><br />Sarc

 

[Chris1956]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

Sarc - The carb rebuild kits contain just gaskets and are just $4-5 ea. You can also get idle needle and seat and gaskets, if you need them for ~ $20/carb. If your needles and seats are not leaking, just get the gasket set. It has been said that the gasket sets are available at auto parts stores. I have not had that experience. I do know they are available through discount marine places, althought you will not save a lot of money on a five dollar part, versus the Merc Dealer.<br />I would disassemble and soak the carbs, then blow them out with Carb Spray or air, reassemble with new gaskets (no sealers)and see what happens. I have not used Seafoam, and therefore cannot say what it can/will do.

 

[mellowyellow]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

sounds like it's flooding to me... see any gas<br />leaking out front of carbs when u squeeze primer<br />bulb? does primer bulb stay hard after primed?

 

[sarconastic]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

Primer bulb pumps up solid as a rock, when runningit is very firm but not as hard as when you primeit. There is a little gas leaking from carbs around the brass screws on the bottom of the bowls but not a ton.<br /><br />When its runningit doesn't sound likeits flooding out, it just sounds likethe throttle will not advance any more, even though the butterflys are opening and the timing is advancing. like it isn't getting anymore fuel.<br /><br />Sarc.

 

[Clams Canino]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

Max advance should be TWENTY ONE degrees NOT 23. (Unless you wanna melt some pistons) Easiext way to check the timing is to put a timing light on #1 and have a friend got WOT while you check the indicator.<br /><br />-W<br /><br />

Originally posted by Sarconastic:<br /> WHats the procedure for checking the timing on this motor? I have a manual coming but it will be a week before I get it. I read somehwere about the timing being set at 23 deg BTC but would appreciate a procedure from anyone.<br /><br />Thanks<br /><br />Sarc.

 

[jrfich]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

hi was just wondering if you solved your motor problem.i have a 85 hp merc. thunderbolt doing thesame thing.someone told me it was the exhaust plates?

 

[Barnacle_Bill]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

If the boat has sat up for three years, your carbs are most likely gummed up. Be sure to replace the needle and seats after cleaning. I got lucky once with the same problem by dumping good carb cleaner in the gas and just running it.

 

[sarconastic]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

jrfich<br /><br />I haven't solved the problem yet. Still aiting for the manual to come. i don't wanna tear it up if' its simple. I am going to try using cleaner in the gas and runningit to see if it will help some first though. I will let ya know though.<br /><br />Sarc

 

[sarconastic]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

Ok all I ay have the problem with this motor but before I start it I need some help. I just wnet out and ran some cleaner into the carbs. and decided to start checking everything I could without the manual and from what you guys have told me on here. Found a small water leak in the line to the head but that's not it. <br /><br />I decided to pull the Dist. Cap off and before pulling it I noticed the ring holding it wasn't clamped down straight. So I pull it off and first thing I see is brass shaving in the bottom of the cap. and that the tops of the contacts on 3 Cyl. are worn off alittle bit. Not terrible but very noticable. I clean the cap out with carb spray. and immediately when I put it back on realize that it was definately dropped down on one side and causing a serious misalignement. Now for my question before I start it up. WHen I put the cap back on it rotated the position of the cap about 1/4 to the rear of the motor. Do I need to adjust the timing any prior to starting to prevent damage or can I start it and then check timing.<br /><br />ANy help appreciated <br /><br />thanks<br /> sarc

 

[emckelvy]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

Man, the cap being off like that would certainly make it run bad! Plus the shavings bouncing around in there would play heck with the spark!<br /><br />It shouldn't hurt to start and idle the motor. Before you do any full throttle runs, it'd be a good idea to re-check and adjust the timing as necessary.<br /><br />Sounds like maybe you're getting to the bottom of the problem, though!

 

[sarconastic]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

ed <br /><br />I started it and it seems to be running a lot better. I checked the timing running at idle at it is right now set at a little before the #1 on the timing marker. it looks to me to be about 2 Deg retarded. WHat is the idle timing setting and which screw do i adjust for this..<br /><br />man I hate waiting for manuals.<br /><br />THanks<br /><br />Sarc.

 

[rrushing]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

sarc-<br />i'm starting to restore a '71 1150 thunderbolt and i will most likely have the same problem. i haven't even cranked mine yet. i have some corroded wires at inside wiring harness and i'm trying to find a replacement part. i've started chiseling away at the rubber housing to try to get enough good wire to be able to mend it.<br />i'm curious, did you order a factory manual or the seloc or clymer version?<br />-ruth

 

[sarconastic]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

rrushing.<br /><br />I ordered the Seloc, only becuase it's the only one I can get Locally. not sure if it's the best.<br /><br />I will give you one tip when your repairing your wiring, don;t just run down to your local True value and pick up wire. You need to use marine wire, it has each individual copper strand in the wire coated to prevent corrosion. I redid all the wiring in the actual boat and had to replace some wiring under the cowl too. Also make sure you use Marine grade connectors. These are also coated and come with a heat shrink wrap already on them. So you crimp then heat shrink it shut. They're pricy but worth it. I had to redo my entire boat wiring because they didn't use the right stuff when someone replaced some wires. <br /><br />I also have a tip about your harness. once you get the wires spliced/repalced in your harness, make you offet your connectors so that when your done you don't have a big glob of connectors in one spot. I had to repair mine in one place from a screw some idiot ran through the transom. Then once your done with your repairs, buy a roll of Shrink Tape. This stuff comes in rolls like electrical tape but is much thicker. It wraps like elec. tape, but you overlap it by hald its width, then hit it with a heat gun and it glues itself together. Works great and give a watertight harness again. I even went a littel overboard on mine and brushed all the wires with Liquied electrical tape prior to wrapping. This helps in keeping the wires from chaffing against each other inside the harness. It dries fast and stays flexible.<br /><br />Good Luck<br />Sarc.

 

[sarconastic]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

Sorry about all the typos in this forum. By the time I get here to type, I'm exhausted and not thinking about spelling. My fingers don't move as fast as my brain. Sorry.<br /><br />Sarc.

 

[Clams Canino]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

Don't worry about the timing at idle - that sets via the idle adjustment. DO recheck the WOT timing and make sure it's no more than 21 degrees advance.<br /><br />-W

 

[rrushing]

Re: Merc 1150 Won't accelerate, Starts & Idles great.

sarc-<br />thank you so much for the information! i know this can't be the correct way to repair a harness, but i was having so much trouble finding one without having to buy a whole boat to get it. i am a beginner with this stuff, so your advice really helps. i guess a marine store would have the correct wire and connectors i need, but where would i get the liquid tape stuff??? <br />-ruth