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3.7 Won't stay running

Hey I just bought a an '86 Sea Sprite 195 with a Mercruiser 170 in it. Took it out on the lake, it drove really well except when I throttled up quickly it would die, so we had to feather it up to WOT. Ran great.

Took the carb to a guy to clean it, he cleaned it and painted it black. i could smell the new paint. Installed the carb, it will turn over and run at 2-4k RPMs if I'm pumping the throttle but it won't stay running. It just dies.

My guess is he clogged pilot circuit.

I also put on a new ignition and think I got the wiring right, but could it be that the wiring isn't hooked up right? But then it wouldn't even start up right?

Thanks for any help. It's getting fuel, air, and spark because it runs at the higher RPMs but just won't stay idling.
 
Hey I just bought a an '86 Sea Sprite 195 with a Mercruiser 170 in it. Took it out on the lake, it drove really well except when I throttled up quickly it would die, so we had to feather it up to WOT. Ran great.

Took the carb to a guy to clean it, he cleaned it and painted it black. i could smell the new paint. Installed the carb, it will turn over and run at 2-4k RPMs if I'm pumping the throttle but it won't stay running. It just dies.

My guess is he clogged pilot circuit.

I also put on a new ignition and think I got the wiring right, but could it be that the wiring isn't hooked up right? But then it wouldn't even start up right?

Thanks for any help. It's getting fuel, air, and spark because it runs at the higher RPMs but just won't stay idling.

what about the fuel ? filters ? vacuum leak ?

engine not getting fuel will cause poor idle..no fuel,dirty fuel,no vacuum..if you have no vacuum it can not suck the fuel out of the carb ...when you pump the throttle your bypasssing the vacuum thats why it runs..


could be the carb/intake gasket etc...
 
Stupid question but how can I ensure there is proper vacuum? Also, is there supposed to be a gasket between the carb and the engine? When I pulled the carb there wasn't one, and I didn't replace it with one, but ...

Also, timing...what are you opinions? Could it cause a once running engine with poor acceleration to now not idle with a clean carb? (Hope that made sense).
 
Stupid question but how can I ensure there is proper vacuum? Also, is there supposed to be a gasket between the carb and the engine? When I pulled the carb there wasn't one, and I didn't replace it with one, but ...

Also, timing...what are you opinions? Could it cause a once running engine with poor acceleration to now not idle with a clean carb? (Hope that made sense).

your ignition work ? what did you do exactly..igniton what ? coil/cap/rotor/complete distributor assy,ignition control system ?

when you disturbed the ignition what did you set the timing to ?

did you check timing before having any work done ?

vacuum is checked much like pressure, you use a guage that is designed to measure this ..good idle vacuum is 15-21 inches..this would be the area directly under the carb called the intake manifold.

all carbs have gaskets to seal the surface under them ..
 
Ok thanks for the reply.

I haven't touched ignition or timing or anything. Just wondering if I should be doing that.

Ok sitting here thinking about reinstalling the carb when I got it back. Did something really stupid that might be my problem. So the bolts coming out of the engine that the carb sits on (4 of them). I put the washers on there, THEN put the carb on top of those. So right now there's no seal whatsoever between the carb and the engine. I'm sure this is causing at least part of the problem.

I'm so stupid, anyways I'm gonna fix that tomorrow morning and see where that takes me. Can I make a gasket or do I need to buy one? Do you guys know if Autozone sells marine grade gaskets? Or are gaskets just gaskets...?
 
I also put on a new ignition and think I got the wiring right, but could it be that the wiring isn't hooked up right? But then it wouldn't even start up right?

I haven't touched ignition or timing or anything. Just wondering if I should be doing that.

So, witch is it???????????????
 
Haha sorry! New ignition switch. Made it a push button start...sorry not ignition like points or anything. Ok so once I fix my dumb a$$ problem, if it still isn't running right, should I be looking into points and timing??
 
you should change your points anyway......the book will tell to gap them at I think 22 or 23 and if you do your timing the book says 8....but mercruiser recomends you do your timing at 10 do to the newer gases ...............
 
I also put on a new ignition and think I got the wiring right, but could it be that the wiring isn't hooked up right? But then it wouldn't even start up right?

I haven't touched ignition or timing or anything. Just wondering if I should be doing that.

So, witch is it???????????????


mounting the carb ON TOP OF WASHERS .. now I find that funny....
 
I know, right?!? I feel like a moron, I have NO CLUE why in the hell I would've done that. Anyways, I took the carb off, put the washers ON TOP!!! and now all is working well.

Well, it's running. Have a slight mixture problem and I probably need to do points/timing. Dad's coming over to help me with timing and I'm goign to get a Pertronix 1146a conversion kit with a new coil and new wires. Should be rockin' Thursday when we hit the lake again.

Thanks for the help guys. Are you sure its set to 10? I thought I saw a service bulletin that says with the new gases it goes to 4. Now I'm confused...thanks,
 
I know, right?!? I feel like a moron, I have NO CLUE why in the hell I would've done that. Anyways, I took the carb off, put the washers ON TOP!!! and now all is working well.

Well, it's running. Have a slight mixture problem and I probably need to do points/timing. Dad's coming over to help me with timing and I'm goign to get a Pertronix 1146a conversion kit with a new coil and new wires. Should be rockin' Thursday when we hit the lake again.

Thanks for the help guys. Are you sure its set to 10? I thought I saw a service bulletin that says with the new gases it goes to 4. Now I'm confused...thanks,

Don't worry about it, that's how you learn. When I was a teenager I wanted to learn how to change the oil in my mom's car. I did everything right except...put the oil pan plug back in. Whoops! She was pissed off when she learned her engine was toast BUT I never forgot an oil pan plug again and that's been 30 years.

You will like the pertronix ignition. Make sure you recheck your timing marks after installing it. Once running take the boat out and warm it up in the water then set your idle-air mixture screw, then set your idle speed.
 
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Hey guys in case you are interested in an update. Took the carb off, cleaned the engine surface where it sits, cleaned the bottom of the carb well. Put a gasket in between, reinstalled the carb.

Bought a Pertronix Ignitor system with a Flamethrower epoxy coil and 8mm wires. Bought a timing light, fired her up, got mixture set good, timing all in place, and now she's running like a champ (all with dad's help! lol).

Headed to the lake Thursday to see how she does under a load. Very excited, she's running way better than when I bought.
 
Hey guys in case you are interested in an update. Took the carb off, cleaned the engine surface where it sits, cleaned the bottom of the carb well. Put a gasket in between, reinstalled the carb.

Bought a Pertronix Ignitor system with a Flamethrower epoxy coil and 8mm wires. Bought a timing light, fired her up, got mixture set good, timing all in place, and now she's running like a champ (all with dad's help! lol).

Headed to the lake Thursday to see how she does under a load. Very excited, she's running way better than when I bought.

thats good having someone to give you some knowledge/help on repair ..take dad out for lunch ...
 
you may want to take some tools out with you on the lake. There is no replacement for a real sea trial. Then once you've run around for a bit and warmed the boat up real good, then check your ilde /air mixture again.
 
Pugent Sounder is providing you with solid advice. He's has nutured his 3.7L since Noah built his ark. No pun or insult intended.
 
I was planning on doing that, so thanks for the reinforcement. Ok so what is the proper way to check A/F mixture on a boat. I used to do minimal work on my fourwheeler and it was to put a new plug in, run it hard and check the plug. I can't afford and I'm too lazy to buy 3-5 sets of plugs and check them each time.

Opinions??

Disregard this post, I found the carb manual that explains how to properly do it. Thanks for all the help, I'll let you know how she does with a load tomorrow..
 
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He He Sounder. I once forgot the drain plug in my dads truck once, but the puddle of new oil all over the drive way was a dead giveaway before I started the engine.
I still hear about that one.
I could not imagine if I had smoked the motor.

Anyway back to the post.
Do you guys pefer a dwell meter or do you just use the gap on the points?
 
He He Sounder. I once forgot the drain plug in my dads truck once, but the puddle of new oil all over the drive way was a dead giveaway before I started the engine.
I still hear about that one.
I could not imagine if I had smoked the motor.

Anyway back to the post.
Do you guys pefer a dwell meter or do you just use the gap on the points?

i use pertronix, don't need either!
 
Lake update:

Ok got to the lake about 10:00 in the morning, fired right up! I like the new ignition, I barely punch the push button ignition and she's running!

Properly warmed up, idled to the free zone then gave her full throttle. She has a slight stutter, no more than a 1/10 of a second, as its advancing. Hard to explain, but the sequence is: full throttle > slight immediate increase in RPM > 1/10 or so second "blank period" > then revs up to full throttle.

Lots of power for a 4 banger. Anyways ran great and strong all day long. Fired right up. Tubed, wakeboarded, got up to 39 MPH by GPS with 3 people and gear! Then drove through an idle zone for a few minutes then went back for another fast run to dry the ladies hair. Gave her near full throttle and she died, wouldn't start for 10 minutes. Showed symptoms of being flooded. Finally got her started, ran at 3200 RPM for about 10-15 minutes, came back to the idle zone to load up and go home. While waiting for truck/trailer, she died again out in the middle of the idle zone.

Couldn't do anything to get started. Had to paddle to shore then drag in stomach deep water around the shoreline and push on to the trailer.

Pissed me off! Still can't get her started today. Waiting for a friend to help me check for fuel and spark (can't see if fuel squirting at the throttle lever).

Why would it run beyond great all day, then just die in the idle zone and never start again???

Update: she turns over fine while holding the ignition, but when I release the ignition she fires on a cylinder, but just won't start. Opened up the throttle and looked down into the intake manifold and there's a huge puddle of gas sitting in there. Think that's a problem?
 
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If it fired right up and idled smooth initially I would say your ignitor is set fine, if you followed the directions from pertronix it's pretty fool proof. Did you reset your timing? Did you reset your carb out on the water when it was warmed up? It sounds like carb problems. Give the carb a squirt of starting fluid and see if she fires up. If so then it's back to the drawing board for the carb. The hesitation when giving full throttle sounds like the carb is out of adjustment or dirty. You might want to put a vacuum gage on it too and make sure you have no air leaks.

The Mercarb can be a little tempermental until it's adjusted right. Try a base setting in the driveway of 1 1/2 turns out from closed on the idle/air screws. Then lake test it, if it still ildes rough or dies when idling give the screws one more full turn out. Mine has been idling like a champ this year when I did that. Last year I tried adjusting by ear and didn't do very well. one screw was way out and other was way in. Sometimes it would die while docking and sometimes it wouldn't. Now it does great.
 
Yeah I did set it about 1 1/4 turns out on the lake. Seemed fine by ear. How does the A/F mixture screw work? More out = more gas or more air? But what kills me is it idled "fine" for about 15-20 minutes then just died (at end of day). Then wouldn't start to save my life.

Timing and everything was great before we went out, I'm headed out now to disassemble distributor and make sure everything is good.

I think it is a carb problem as well. Pisses me off because I just spent $100 for a boat mechanic on Craigslist to do it on the side. He was kinda fishy, so I'm doubting he even cleaned it. This really all makes me so mad. I'm really wasting my money. I don't mind spending money when it fixes a problem but I hate spending hundreds of dollars for something to just get worse.

Thanks for all the help you guys are giving me. Gonna recheck timing when I can find someone to help me. Not even thinking about putting it on the water until I can get it fired up. Plus I don't have the opportunity to get to the lake until Labor Day. Then it'll be time for winterization. I might just be done for the season...
 
If it fired right up and idled smooth initially I would say your ignitor is set fine, if you followed the directions from pertronix it's pretty fool proof. Did you reset your timing? Did you reset your carb out on the water when it was warmed up? It sounds like carb problems. Give the carb a squirt of starting fluid and see if she fires up. If so then it's back to the drawing board for the carb. The hesitation when giving full throttle sounds like the carb is out of adjustment or dirty. You might want to put a vacuum gage on it too and make sure you have no air leaks.

The Mercarb can be a little tempermental until it's adjusted right. Try a base setting in the driveway of 1 1/2 turns out from closed on the idle/air screws. Then lake test it, if it still ildes rough or dies when idling give the screws one more full turn out. Mine has been idling like a champ this year when I did that. Last year I tried adjusting by ear and didn't do very well. one screw was way out and other was way in. Sometimes it would die while docking and sometimes it wouldn't. Now it does great.


this is the same problem from the first posting. It must be fuel/fuel tank contamination etc..
 
Hey Seasprite 195, the merc. update on timing brought the setting from 8 degrees down to 4 degrees BTDC. *But 4 degrees does not seem to work well with the Pertronix setup. Most of the guys on Breezeworks 470 Talk that have the Pertronix setup set it at either 5 or 6. My engine seems to idle best set at 6. It idles at around 650rpms. The reason was the newer e-10 fuel was causing pistons to melt when set at 8 degrees. I have a 1988 3.7lx 180 hp and have done all of the upgrades. Make sure if you put the pertronix flamethrower or flamethower 2 coil on your engine that you remove the purple wire that goes to the electric thermal choke if you have that setup. You need full 12 volts with the high output coils. The factory coil needs 1.5 ohms of resistance and that is why the wire is run from the coil to the electric choke mechanism. The high output coils are 3 ohms. I ran a dedicated wire from the ignition switch to the coil and that assures me that I am getting plenty of juice. (12 gauge) Probably overkill, but I had spools of it so just used it up. lol I had a problem not too long ago and thought it was fuel related. The engine went from running and idling fantastic to just running like crap. So I went through all the nonsense of changing water seperator,carb filter,inline filter,etc.
Thought I had figured it out but symptoms came back again, rough idle, slight popping at the carb and even an occasional backfire. Anyway, it turned out that the ignition switch was shot which in turn was providing intermittent power like and on and off switch to the coil. My engine stunk like unburned fuel also when the condition made itself present. I searched and searched for hours and hours trying to diagnose the problem and finally made my way to the keyswitch. Reached around the back of the dash,wiggled the housing on switch and also turned key at the same time and the engine would fire right up (Oh, I forgot to tell you that sometimes the engine was a real bear to start also!) I even took the flame arrestor off because I thought the choke adjustment was off. It turned out that the on position or pole on the switch was toast. The engine would turn over everytime but the coil was not getting voltage or sufficient voltage. So what the heck do I know but "don't rule out electrical" at least not yet! lol only the best, Tom
 
If there is not any spark the condenser may have shorted out. For the hesitation it sounds like the accellerator pump was not replaced or is bad. The flooding is most likely that the float lost its setting--it happens. You can replace the acc. pump and set the float--get a new one if it weighs more than a sheet of copy paper. Follow the directions for setting it; very simple. You'll need new top and base gaskets; get all of your parts from a dealer. Check/set the timing @ 4 deg. BTDC.
 
Ok guys, thanks for the advice. When dad and I did the timing, the engine ran best at 8 but I'll be sure to go down to 4-6. I might be redoing the carb and accel pump myself, I don't trust the guy that did it. Also I am getting spark and have the Flamethrower coil. Still need to put a fuel filter on it. Going to do all that tonight hopefully...thanks again

OH yeah found a big problem (I think) and am going to fix it and see if that helps. I throttled to full to open the butterfly valves to look into the intake manifold. Noticed some gas just sitting in there. Took the carb off, grabbed a 10mL syringe and sucked out about 50mL just pooling in the intake manifold. Gonna put the carb on and see what she does.
 
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Ok guys, thanks for the advice. When dad and I did the timing, the engine ran best at 8 but I'll be sure to go down to 4-6. I might be redoing the carb and accel pump myself, I don't trust the guy that did it. Also I am getting spark and have the Flamethrower coil. Still need to put a fuel filter on it. Going to do all that tonight hopefully...thanks again

.

OH yeah found a big problem (I think) and am going to fix it and see if that helps. I throttled to full to open the butterfly valves to look into the intake manifold. Noticed some gas just sitting in there. Took the carb off, grabbed a 10mL syringe and sucked out about 50mL just pooling in the intake manifold. Gonna put the carb on and see what she does.

I bet the float adjustment or the needle valve/ seat is messed up causing the flooding condition as you just described here.
 
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