1st boat, having some problems. please help

[Caddiepmpn]

i bought an 89 renken 17' bowrider with an 85 johnson 150hp vro. this is the first boat i have owned and i love it but im haveing some problems. thanks is advance for any help.

problems:
1. fouling out plugs every time i go out. the gas is premix and i was told buy the guy i got the boat from that i need to put 1 cup of oil for every 5 gal of gas. does this sound right? also im using ngk plugs. is that ok for this motor?

2. for about the first ten min out on the lake the boat surges real bad. it will pull strong then lose power for a few sec. then pull good again with out touching the throttle. is this normal untill it warms up?

3. using the boat for wakeboarding. the motor will change speeds on it own when pulling. it will be fine for a min. then it will rev up and go faster on its own. if you bump the throtle down it goes way to slow. it olny does this while pulling. if im runing about 15-20mph with out the load its ok.

4. chargeing system. i put 2 new bateries in the boat when i got it. if i charge the bateries fully when i get home than it will run fine off of one most of the day but i will have to change to the second one after a while. also my tach doesnt work. i read somewhere that this may be related some how.

 

[HighTrim]

Re: 1st boat, having some problems. please help

Welcome to iboats. First things first, what checks or maintainence have you done? On a new boat if you're unfamiliar with the history, id reccomend changing the impeller, nothing to do with your questions, but nonetheless. Secondly, I believe you need to mix at 50:1. Check the compression and spark FIRST before adding any parts, then report back. As far as the undercharging, that could be due to many things, voltage regulator, connections , etc. If your rpm gauge does not work, you will need to check your rectifier diodes perhaps, after the wiring of course. Do you have an ohmmeter, if so i can walk you through the steps.

PS a manual for you will pay for itself many times over, check ebay.

(Compression & Spark Test)
(J. Reeves)

1st - Regardless of what problem one might encounter, always start with the basic troubleshooting procedure. Check the compression which should be in the range of 100+ psi (somewhat less on the smaller hp engines) and even on all cylinders.

2nd - With the spark plugs removed, rig up some type of spark tester whereas you can set a gap to be jumped. On magneto ignition systems.... and also the Battery Capacitance Ignition system OMC engines from 1968 to 1972, set the gap to 1/4". On the solid state OMC ignition systems from 1973 to the present, set the gap to 7/16". The spark should jump the gap with a strong blue lightning like flame..... a real strong blue snap!

If there was no spark, on engines from 1973 up, disconnect the RED main electrical plug at the engine. Remove the s/plugs. crank the engine via the starter solenoid (jumper bat term to small 3/8" term nut, not the ground nut) and observe spark. If spark is now okay as stated above, the usual cause is a shorted ignition switch.

If the above checks out as it should, and the engine dies out when throttle is applied or won't idle, it is usually due to one or both of two things. The carburetors are fouled, in which case the cure would be to remove, clean, and rebuild them..... or the timer base under the flywheel is sticking which would result in a retarded spark. If the engine will not fire/start at all even though you have the proper spark and compression, it's usually due to fouled carburetors.

To check the timer base for sticking (Engine Not Running), spin the prop to align the shifter dog with forward gear and while doing so, put the engine into forward gear. Now, while watching the timer base, slowly apply throttle clear up to full throttle. The timer base should move smoothly all the way up against the black rubber cap that is atached to the end of the full advance spark setting screw. If the timer base sticks, find out why and correct that problem.

Usually any sticking of the timer base is caused by one of the four retaining clamps being slightly too tight. Putting a very thin washer under the clamp cures that problem. Some boaters use a thin screwdriver to bend the clamp upwards slightly but I prefer the thin washer. The sticking can also be caused by having a faulty stator start to melt down, resulting in a sticky substance dripping down on the timer base nylon retaining ring.

 

[bigbob_FTW]

Re: 1st boat, having some problems. please help

Is the VRO working? You say you premix. sounds like too much oil.

 

[Dhadley]

Re: 1st boat, having some problems. please help

Start with getting the correct Champion plugs in it. I use (Q)L77JC4's in my crossflows.

 

[Caddiepmpn]

Re: 1st boat, having some problems. please help

Is the VRO working? You say you premix. sounds like too much oil.

the vro is not working. it is premix i bought a mixing bottle last night so i can measure the oil a little more precise.

 

[Caddiepmpn]

Re: 1st boat, having some problems. please help

Start with getting the correct Champion plugs in it. I use (Q)L77JC4's in my crossflows.

whats the diffrence in the plugs? i just got the ngk's cause thats what was already in there. ill definatly try that though.

 

[reload]

Re: 1st boat, having some problems. please help

I think the problem is fuel related. Getting the mix right is important. I don't think you will see a difference in changing plugs. Sounds more like fuel blockage or a cylinder cutting in and out may be.

 

[chbailey]

Re: 1st boat, having some problems. please help

Get a compression and spark test done just to be sure it's not that. Also, switch to a precise mixed fuel. I found this online calculator to help with the fuel mix based on your gallons. So if you fill your tank with 7 1/4 gallons then you can be sure that you get the correct oil mix. Which in this case of 7 1/4 gallons is 18.56 US ounces of oil.

Fuel oil mix 50:1
http://www.csgnetwork.com/marineoilfuelcalc.html

Also, what kind of oil are you using to mix in?

 

[tashasdaddy]

Re: 1st boat, having some problems. please help

the engine was designed to run on champion plugs, and most run better with them. use tcw3 outboard motor oil. i strongly agree on a compression and spark test, if for no other reason than to have a base line, for the future. if you don't have proper compression and spark, all the parts you throw at it are total waste.

 

[HighTrim]

Re: 1st boat, having some problems. please help

The only diff in the plugs is the heat range, manufacturer calls for champions, although i dont know if youll notice a difference in you problems. Mix your oil/fuel exact, these motors are picky and it only takes a second to measure it. And like i said, id reccomend the spark and compression test again b4 all else.

 

[Dhadley]

Re: 1st boat, having some problems. please help

NGK plugs are good plugs but that motor is calibrated to run on Champion's burn characteristics. It probably won't solve the running issues but it may avoid your next question about piston part numbers.

 

[Caddiepmpn]

Re: 1st boat, having some problems. please help

i have been running the pensoil tcw3 oil. thanks for the link to that calculater i saved it to my favorites for future use. i could be wrong but i think the compression and spark is good cause once it warms up it runs like a champ for a while then starts to have problems again later. the boat runs between 40-45 top speed but i usaly olny run it about 30-35mph. ill pull the plugs and check the compression tomarrow just to be safe though. also to check the spark should i just cut the fuel pump off and turn the key or is there a better way to do it? im mechanicly inclined when it comes to cars (i used to be mechanic for kia) but when it comes to 2 stroke boat motors its like tring to read a forein language.

 

[kenmyfam]

Re: 1st boat, having some problems. please help

NGK plugs are good plugs but that motor is calibrated to run on Champion's burn characteristics. It probably won't solve the running issues but it may avoid your next question about piston part numbers.

Dont know if it's just me but I have never owned a 2 stroke motor on anything (moped, motorcycle, outboard, weedeater etc) that actually liked NGK plugs. I have always reverted back to champions and that is all I buy these days.

 

[chbailey]

Re: 1st boat, having some problems. please help

The spark tester should be in-line (between plug and wire) with the motor running. I've never seen it done any other way. Just keep it away from the motor head or anything that will ground it (including yourself :redface.

Oil type should be fine though a lot of guys are recommending switching to the synthetic type.

 

[Caddiepmpn]

Re: 1st boat, having some problems. please help

The spark tester should be in-line (between plug and wire) with the motor running. I've never seen it done any other way. Just keep it away from the motor head or anything that will ground it (including yourself :redface.

Oil type should be fine though a lot of guys are recommending switching to the synthetic type.

ok thanks. ill try that. with cars i have always pulled the fuel pump relay to keep it from starting and pulled a plug wire, stuck an old plug is and grounded it. with the motor turning you can see the spark in the plug. but i know what your talking about though and ill do it like that.

 

[Caddiepmpn]

Re: 1st boat, having some problems. please help

i finaly got to work on it this weekend. the compression is about 80lbs on all of the cylenders. does this sound ok?

i tried to find the champ plugs at walmart but they olny had 2 so ill have to get those later.

i think i found part of my problem though. i pulled the carbs and took them apart to inspect them. the top two were fine but the needle seat on the bottom one was a little hard. i did this because i noticed a little gas in the bottom of the intake when i took the air box off. i think this could be part of my problem.

also where can i find an in-line plug tester?