1990 Johnson 50 HP VRO (VJ50TLESR) Bogging problem

I just bought a 1990 Sunbird SPL-150 2 weeks ago and it ran great at the guys house on muffs at idle and also when he throttled up the engine, but once I got it out on th e lake it will run for about 2 minutes and then bog down and die. It starts right back up and will idle perfectly fine, but once I try to get it moving it dies 10-15 seconds later. I am a complete newby when it comes to boat engines and have seen some posts with people having similar problems, but there are a million different answers that I have found that could be the problem.

The Engine is a VJ50TLESR 50 HP Johnson with VRO, tilt, etc.

I have taken it to an outboard engine mechanic and he said that it has good spark at first, then it has a very weak spark once under load. I don't have the exact numbers, but he said that the compression was good.

I have been reading about Power Packs and Stators, but as I stated earlier I don't know anything about engines and am wondering if this engine is worth fixing.

I do think that the person who sold me the boat knew about the problem because they stripped some wiring and twisted it together (Hot wire) that appears to have had an inline fuse in it before to bypass the fuse.

I hope I'm not beating a dead horse here with this post and would like to say Thank-You in advance for any replies/suggestions. My wife and I have spent a lot of money buying and then trying to diagnose the problem on this boat so far and I would really like to try and find out what the problem is so I can decide whether to continue trying to chase the problem or just sell the boat and the engine for parts.

Re: 1990 Johnson 50 HP VRO (VJ50TLESR) Bogging problem

Forgot to add that I have had the Thermostat replaced, new plugs put in and the water pump checked and all 3 of these Items seem to be OK right now. I really think it is an electrical problem due to the weak spark.

Re: 1990 Johnson 50 HP VRO (VJ50TLESR) Bogging problem

Lack of backpressure on the underwater exhaust enables it to run fine on the muffs then crap out when you put a load on it. On land it probably only needs one cylinder to idle and, if you aren't familiar with its sound you might not even notice.

It seems like there's "a million different" possibilities, but really there's only three: compression, spark, fuel. If she gets all three she runs; if she don't, she don't.

If the spark on both cylinders is weak under load then there's a fault in the ignition system. You can check this yourself with an inline spark tester (couple bucks at auto zone). Set the gap at 7/16", clip it to the block, attach the leads (one at a time) and look for a strong blue spark while cranking. If it won't jump a half-inch gap, then it won't fire in the hole under load.

Any qualified competent johnson/evinrude tech will have test equipment to pinpoint the exact cause within minutes. You could do it yourself with a multimeter and direct voltage adapter.

There should be a 20-amp fuse in line with the 12V feed to the keyswitch (red wire just on the powerhead side of the big red wiring harness plug). It's there for a reason. If the other guy was constantly blowing a 20-amp fuse, you're at risk for a fire on the water. It's just basic 12V wiring -- if you want to tackle it yourself, you can get plenty help right here on iboats.

If it has good compression it's worth fixing. You may decide you don't want to mess with it and, that's ok, too. Seems to me, that boat with only 50hp might very well be underpowered.

Welcome to the forum!

Re: 1990 Johnson 50 HP VRO (VJ50TLESR) Bogging problem

Thanks JTexas!! I really don't want to get rid of the boat if I don't have to. I think I am going to pick it back up from the repair guy tomorrow and see if I can't try and do it myself (with lots of help from this site)... I think my cousin might know how to do some of this stuff and he is closer than an hour away.

Re: 1990 Johnson 50 HP VRO (VJ50TLESR) Bogging problem

John was right about it being the red wire with the fuse. This is turning into the boat from hell... Was taking the boat back to the lake and got a ticket for the tail lights being out on the trailer (I had a receipt for the new lights and they were in my truck when I got pulled over). After spending the afternoon replacing the electrical wiring on the trailer it finally works and I was able to get the ticket dismissed after showing the police officer. Now it is at a respectable marina to be diagnosed. I'm beginning to think that God does not want me having a boat right now..LOL...

Re: 1990 Johnson 50 HP VRO (VJ50TLESR) Bogging problem

That motor will be fine once you get it tuned and running properly. If you choose to do your own maintenance, you probably won't ever have to put it in the shop again. You may have to spend some quality time with a wrench in your hand, but hey, there's worse ways to spend a Saturday afternoon.

I bet God is just making sure that you really, really want a boat...

Re: 1990 Johnson 50 HP VRO (VJ50TLESR) Bogging problem

Well, Looks like I need a new engine. Bad compression in this one and the marina said that this engine is shot. Luckily I'm a nice guy because the person who sold it to me saying that it ran is going to get a nice earfull soon.

Found a 55 HP Johnson '69 for $100 that supposedly runs, but not sure if I want to go with an engine over 50 years old without knowing anything about it.

Re: 1990 Johnson 50 HP VRO (VJ50TLESR) Bogging problem

too bad about the compression.

Personally I have no experience with that vintage, but if you'll search this forum I think you might get warned off it. Myself, I'd be more comfortable with at least a late-70's and beyond.

Since you're repowering anyway, look for the USCG rating plate on the boat, it will have a "max hp" rating -- I have found that if you're under 70% or so of that rating, you'll feel underpowered. I have a feeling that your hull was meant for a bit more than 55hp. Could be wrong, though.

Re: 1990 Johnson 50 HP VRO (VJ50TLESR) Bogging problem

How hard is it to part out an outboard motor. I was told that the powerhead and hydraulic t/t were shot, but that the starter, lower unit, fly wheel, etc... were still good. Am I better selling the boat with the motor on it (even it does not work) or should I take it off the boat and try to part it out or sell the broken motor outright? About to put the boat up for sale (cannot afford new/used motor to replace broken one) and am trying to decide how to sell it.