1990 48 SPL runs only when primed.... HELP, VERY frustrated!!

[DBoots]

I prime the engine and it runs long enough to burn that fuel, then quits. I have new fuel pump, new gas line/bulb from fuel tank, fresh fuel with 50:1 ratio and put in Seafoam to 1 gallon, rebuilt/cleaned the carbs, new primer solenoid, new plugs. Gas getting to carbs. If I put in gear and throttle the engine up on start up will rev for a second then die. New to working on boat motors, very much a novice. Watched youtube for help. Any suggestions will be taken!! AT my wits end and think it's gotta be something simple I'm missing.

 

[flyingscott]

What is your compression? Do you have good spark to each cylinder? Maybe revisit your carb work.

 

[racerone]

What are the low speed mixture needles set at ??----Did you confirm that high speed jets in the carburetor bowls are clean ?

 

[DBoots]

It runs fine when I prime it and will continue to run as long as I am hitting the primer solenoid on the ignition. I installed an in line fuel filter in the fuel line from gas tank because I found no fuel filter. The filter runs low on gas and I have to keep squeezing the bulb to keep gas going to it. It's like it burns the fuel, but the tank is not giving it the gas it needs to continue running on it's own (not siphoning fuel from tank to carbs). I thought maybe the vent on the fuel tank was clogged, so I took the entire cap off and no difference. Again, I just installed an Evinrude fuel pump, would a defective fuel pump cause this? The mixture needles were put back to the original position, 2 1/2 turns from bottoming out on bottom carb and 2 1/4 on the top. The carbs didn't look bad, but there was green and gunk on the brass stem that goes toward the bottom of the float bowl (not exactly sure what it's called, excrusion tube?) in the middle of the carb. Maybe didn't clean good enough? As far as the high speed jets, appeared to be clean, but couldn't remove, sprayed liberally with carb cleaner. Looked like last joker tried wrong screwdriver. Head was messed up and didn't want to make it worse. I do not have a compression tester at this point, I guess I was assuming I have spark or wouldn't run when it is primed, am I wrong about this?
Back story is I bought this boat and motor back in March and it has done the same thing since I got it. Yes, bought it without hearing it run, my very big mistake! Owner, of course, said "runs great!" and I took him at his word because it was cold and he didn't have earmuffs. Never again, but was hoping this was water ready and haven't been able to even put the boat in the water yet. Have rebuilt the gearcase due to water in the gearcase, replaced water pump, wasn't changed in awhile (due to seeing the fins very worn.), rebuilt the tilt and trim, which owner said was having some problems with, found it needed new cap seals and a short in the connector. Anyway, after a lot of new parts and a lot of blood and sweat, still not running. Like I said, I'm new to working on boat motor, but found it was a necessity in my case or spend ALOT of money to have a mechanic work on it. Trying to learn and do everything myself.
Thank you for your replies! I have to wait for another payday to get compression tester. Meanwhile I have to go back to work and won't have time to mess with it again for awhile. Sorry for the "book" I wrote!

 

[juno pierrat]

did you remove core plugs on top of carbs during carb rebuild, and insure 2 small holes under the plug are not plugged, that's part of the idle circuit

 

[DBoots]

I replaced the large plugs and removed, cleaned and replaced the lead shot beside it. I probably will go back in and clean the carbs again. I used carb cleaner and brake parts cleaner. There are other lead shot places that I didn't mess with due to having to buy the lead shot and I didn't know there was that many, thought there was just one beside the large plug. I understand that dipping the carbs in solvent is not recommended because of the plastic parts, at least that was what a marine mechanic on youtube was saying. Like I said, I'm a novice at this to say the least, I'm learning as I go, so I'll take all advice given and appreciate all the replies! I'm just confused as to why the fuel isn't being pulled through the fuel line. I have new line and bulb primer too. It runs awesome as long as I keep hitting the primer solenoid and squeezing the bulb to keep the fuel going in the line, not sure why the carbs aren't "taking over". I tried to increase the throttle, it will rev higher and then die because it runs out of fuel. I need to check the fuel pump, even though it's new, it could be defective. Thanks to the replies, I have a lot of work ahead of me!

 

[racerone]

Facts for you.----The primer valve put fuel directly into the carburetor throats just in front of the reed valves.---This fuel bypasses the metering circuits in the carburetors.------You need to revisit carburetor work.----Revisit slow speed needle adjustment.----Remove line from pump to carburetors and crank the motor over.----Does fuel pulse out of the pump ?---How did you determine that carburetors have run out of fuel ?????

 

[juno pierrat]

are floats adjusted and is the spring clip in place holding the needle to the float arm

 

[DBoots]

To answer the questions, I have not been able to check the fuel pump yet to make sure it is working, due to having to work myself, will be off Weds! I have rebuilt the carbs, and in the kit were new floats and valves and the springs are in place. I will double check that they are opening when I go back to clean the carbs again. I found that the old floats were not right when I measured, and thought that was the issue as to why the motor wouldn't run, due to the valves not opening to let fuel in the carbs, so when I installed the new ones, I measured the base of carbs to base of float and are at 1 and 1/8 inches. I also bought the carb adjustment "plate" tool and the carbs were great according to the plate, floats are level and conform to the plate. I am assuming that the carbs are running out of fuel due to the fuel level lowering in my in line filter after I have hit the primer solenoid and the motor running and I have to squeeze the primer bulb to get more fuel in the filter. There was fuel in the bowls when I removed the carbs to rebuild. I guess I figure that the fuel was not entering the motor from the carbs and the fuel I was losing was from the primer solenoid. Thank you for telling me about how the primer works also! That's a big help. I have a question about the slow speed needle adjustment, are you referring to the mixture screws where they were 2 1/2 turns from bottom and 2 1/4? From what I understand, that's the "starting point" and when the motor is running you adjust to where the motor runs best. I'm a little confused. Like I said, you're talking to a Novice. Something must of got missed due to all the sweat in my eyes! I will keep at it and will let you know what happens when I'm able to work on it. THANK YOU for all the replies and help!! I am very grateful for the knowledge from people who know!

 

[webbd]

"The filter runs low on gas and I have to keep squeezing the bulb to keep gas going to it. It's like it burns the fuel, but the tank is not giving it the gas it needs to continue running on it's own (not siphoning fuel from tank to carbs)."

Could there be an air leak in your fuel line from the tank that causes your fuel pump to suck air instead of fuel? If so, what happens if you bypass the fuel line and connect to an auxillary tank?

- DW

 

[racerone]

Way back ( 50 years ago ) the customers used to comment on the way the filter behaved.----I explained it many times that the filter bowl on their 1963 18 HP filled up when operating the primer bulb.----But the motor ran just fine with it looking " empty " during operation.-----So remove the airbox in front of carburetors.----Remove drain screw on upper carburetor.-----Fuel should run out.----Now operate the primer bulb.----Does fuel now run out of top carburetor ?-----Then crank the motor over and see if fuel runs out.-----Now install plug and repeat the test with bottom carburetor.

 

[ct1762@gmail.com]

are you sure you're running on both cylinders? the link n synch has to be precise with these newer style motors. the spark advance link rod and roller need to be within spec. the cam roller on the carb needs to be present. if it's not set up correctly, it can stall after a short time. as suggested, do a compression test (buy a 20 dollar guage at any auto store). then pull the plugs after it's stalled. plug should not look bone dry. i'd get a factory service manual from ebay for $15.

 

[DBoots]

I got a service manual and there was about 10 things it could be for engine stalling, I was hoping that someone had the same experience to kinda narrow it down. I will be working on it tomorrow, finally off work for a few days. I plan on recleaning the carbs and double check everything and remove all the jets, whatever it takes. I will also try the carb drains and run the motor and see what happens. I bought and installed the new rollers also. It just had the black part and not the plastic. Just looking at it, they're adjusted correctly from what I can tell. The arrow is pointing at the roller in the back and there is a slight gap in the front, so I believe that it correct. I spoke with a friend that used to work on small engines and he thinks carbs clean again and maybe a vacuum leak, so I plan on replacing all the fuel lines. The primer bulb and fuel line from the tank to motor is new. Will also do compression check. What is an acceptable level for each cylinder? I know that they are supposed to be close together in pressure. So, I have a lot of work ahead of me and hope the weather will cooperate! Thank you again for all the replies and help guys! I really appreciate you taking the time to help!

 

[ct1762@gmail.com]

as long as they are within 15 lbs of eachother and relatively high (over 100 psi) for this motor you should be ok. of course some meters are way off, which is why the factory never publishes actual values for fear of a warranty claim (my theory anyway). the little advance rod (plastic stubby one just under the flywheel) needs to be EXACTLY 5.3 cm long, and everything usually falls perfectly in place after that unless someone screwed with the cam follower (common area). but the manual says something like a 5 thousands gap at cam roller so easy to get it back to spec if its too wide or close of a gap. awesome on getting those new rollers! 90% of them crack and fall off and its all downhill from there with people trying to get them to run right lol. i'm doing an 87' 50hp now and the previous owner used blue masking tape to try to replicate the roller thickness. massive failure.

 

[DBoots]

Some good news, went to Evinrude dealer today and got new fuel lines and vacuum hose. Also got a compression tester from Advance Auto, tried to sell me the $50.00 tester, but found that they had a $30.00 one right beside it. Dude trying to get me to buy the most expensive one! Bad news? Live in South Carolina and supposed to rain for the next couple of days because of the hurricane, so I'm stuck waiting. I'll fill everyone in when I get back to work on it. For the last reply, I thought just the black rollers were normal until I watched a youtube video and the guy said to get the new rollers, didn't even know was supposed to be plastic on top of that black roller! Sounds like the person that did the masking tape may have worked on mine! Again, appreciate all the help!! YouTube was a huge help for me, watched videos on how to rebuild my gearcase and rebuild my tilt and trim, guy was working on a 40hp, but was very similar to my 48.

 

[PLion]

Hi DBoots. I just stumbled upon your post and am actually going thru a very similar troubleshoot on a very similar engine. I just bought a 1990 50hp VRO in June and have had a slew of issues but I was able to get it running for a while. Most recently I've been experiencing the engine dying when the primer is in the "run" position. If I opened the primer (either pushing the key in or moving the red lever to the "manual" position), the fuel would be dumped into the carb throats like racerone mentioned, and the engine would run. This failure was out of the blue and was discovered on the water... the boat took off and then throttled back and died about 10 seconds later. I needed to use a trolling motor to make it back to the dock. I've been troubleshooting all week and believe I uncovered the root cause. We noticed the gas looked a little "off" and decided to dump some into a water bottle to check out. Turns out there was a good amount of water in the tank, and this was brand new gas that I put in the day of the failure. Not sure exactly how the water got in there but my wife mentioned a couple years ago that her car was acting weird after getting gas from the same station I filled the boat up with... maybe a coincidence? Long story short, I put the engine in a barrel with new gas from a can and it's running a lot better on land. Need to put it in the water to confirm.

I believe the water would explain the failure. If there isn't the right amount of gas in the mixture getting pulled thru the carb, then the engine wouldn't have enough fuel to burn. But if the primer is in "manual" mode, and fuel is getting dumped into the engine, then there is enough fuel in the mixture to keep the engine going.

As for your other issue with the gas level in the filter dropping quickly, I noticed that happening to me as well. Turns out I pinched the gas line that runs from the fuel manifold after the fuel pump to the primer solenoid. On my engine, the VRO pump and starter motor are very close together and don't provide a lot of clearance to route the gas lines and the gas line actually had a gash in it allowing air to get in. The engine would run in this state but would act funny under load. Once I replaced the fuel line the engine ran great until this gas issue.

Good luck getting your engine going!

 

[DBoots]

I did finally get to mess with the motor a little today, looked like rain this morning, but started clearing up. Anyway, did get a compression test done, 150 for top cylinder and 148 for the bottom, so I'm pretty sure that's great. Did replace most of the hoses. The vacuum line the dude gave me was too small, so, couldn't change those out, but changed the one's from the manifold to the carbs. I did remove the fuel line to the manifold and turned it over and fuel was pumping out. I'm waiting to get my carb rebuild kits in before tearing in to the carbs again. I sprayed out the manifold with carb cleaner, I'm not 100% sure, but thought I saw a little piece of trash come out, so that MAY have caused an issue if that was the case. Like I said, my motor didn't have a fuel filter on it when I got it, so I added one on the fuel line. I did see where one of the fuel lines coming from the manifold may have been pinched a little, so again, that may have caused some issues too. Haven't tried to run it yet. I heard I needed to get a water separator to help with the issue of water in the ethanol gas, luckily the business I use has non ethanol high octane gas. Don't THINK that's my issue, never had a problem from there before with water. A guy told me the water separator kit was about $129.00 from ebay, may be worth the extra not to have that issue. I'm going to look in to that. Going back to work tomorrow, so I gotta wait to work on it again. Good luck with yours too, at least you had yours on the water! Also, if you had a gash in the fuel line wouldn't it of been leaking gas? Just curious. I haven't seen any gas leaks on mine. Mine hasn't run since I got it and hasn't even been in the water yet! So much for taking someone's word at "RUNS GREAT!". Thought it was going to be water ready...NOT! My mistake for trusting someone!

 

[oldboat1]

Measure spark with an open air tester -- look for 1/2 inch with engine cranking at 300rpm. Why the Seafoam, and how much are you using? The filter screen on your fuel pump should be sufficient. Check it for debris. If you think water is the culprit, pump some from the bottom of the tank into a glass jar and let it settle. Fuel will ride on top, water at the bottom.

 

[DBoots]

The seafoam is to clean up carbon in the motor and to lubricate and clean the fuel system. The mix is one can of seafoam to 1 gallon of gas. Supposed to be a "miracle worker" for motors. Check out youtube videos on it. Also helps with compression. Was hoping that the motor would be running, that's why I had put it in to clean the fuel system. Brand new fuel pump. Don't think I have water, but going to check the gas. Not sure what an "open air" tester is, I'll have to see what I can find. Working on the motor myself, so hard to check the spark and crank the engine, ignition is in middle of the boat. Thanks for the reply!

 

[oldboat1]

Yes. Heard of Seafoam. Check at an auto parts store for the spark tester. Avoid the in-line type, and test with all plugs removed. Use a jumper to extend the ground clip, if that helps place the tester where you can see it.