Motot starts then quits .....any suggestions ?

[OneLuv1979]

OK i recently purchased a boat with a 03 Johnson 115 lsps model ...
Carb motor .....

The boat has sat for several months , and now i own it except when we got it started it ran fine for about 30 seconds then started shaking and popped and quit it would not start again for about 24hours or so then did the same thing .....

I am not to fimiliar with these motors at all , so my 1st thought was rebuild the carbs maybe a float stuck ? I did notice in the center of the prop it has very thick oil , leading me to believe its running rich ....

I just want a lil guidance as to what this might actually be ?
should i start at the carbs ?

Thanks for any help in advance , im still learing ....

 

[tashasdaddy]

Re: Motot starts then quits .....any suggestions ?

if the oil tank is higher than the motor, the carbs are probably full of oil. i have had it happen.

 

[OneLuv1979]

Re: Motot starts then quits .....any suggestions ?

Its not higher then the motor ......


Im just trying to understand if i should just rebuild the carbs ???
I have rebuilt dirt bike carbs and im thinking these should not be much harder, but as i said im a rookie ....

Do you think rebuilding the carbs is where i should start ?

 

[ksubigbuck]

Re: Motot starts then quits .....any suggestions ?

Rebuilding them is pretty easy. You shouldn't have any trouble if you have done it on dirtbikes before. I would say go for it...it certainly won't make it run any worse!

Also, how old is the fuel? You might just need some fresh gas.

Hunter

 

[tashasdaddy]

Re: Motot starts then quits .....any suggestions ?

when trouble shooting start at the easiest, check spark all cylinders should jump 7/16 in with a spark tester. check compression, gauges are different, techniques different, buy you want to read atleast 100psi and all 4 should be no more than 10% difference between high and low.

if this check out ok, then do the carbs. read these:
http://forums.iboats.com/showthread.php?t=225510
http://forums.iboats.com/showthread.php?t=158086
http://forums.iboats.com/showthread.php?t=244013
http://forums.iboats.com/showthread.php?t=313963&highlight=compression

 

[ezeke]

Re: Motot starts then quits .....any suggestions ?

Sounds like it may be overheating - check your cooling system.

What's lsps?

 

[OneLuv1979]

Re: Motot starts then quits .....any suggestions ?

Thanks guys i still have to tackle the stuck on cowling ...
The damn lever broke and i plan to drill it out over the weekend ...

The moment i get it open i plan on checkin compression and if that checks well i will check the spark and if all goes smooth i will be doing the carbs ....

Out of curiosity , how would the engine run if it had low comression ?
would it idle at all ?

 

[OneLuv1979]

Re: Motot starts then quits .....any suggestions ?

Got the cover off today by wiggleing the cover over but the latch is not budging at all ..... Guess i will have to grind it off ....

I ran a compression check and all 4 cyl read 105 ....
Plugs looked horrible so i went and replaced them , now i can not get it to start ....

Checked spark the only way i know how , removed the plug wire and used a plug against the block , its sparking but im not quite sure if it should be a large spark or small spark ?

It wont start at all now , and im confused looking for a lil gudiance ...

 

[tx1961whaler]

Re: Motot starts then quits .....any suggestions ?

What spark plugs are you using?
A spark tester is really what is needed to verify proper spark. They are about 6 bucks at an auto parts store. A weak spark will still jump the small gap of a spark plug outside of the engine, but that might not be the case when the plug is in the engine under compression.

Sounds like the compression is good. Just verify that the spark cracks across a 7/16" gap on a spark tester for each cylinder and that will leave the fuel system as the likely culprit.

 

[OneLuv1979]

Re: Motot starts then quits .....any suggestions ?

Sounds good i will get a spark tester 2moro and i will post up my findings !!!
Thanks .....

 

[OneLuv1979]

Re: Motot starts then quits .....any suggestions ?

Just out if curiousity , does anyone know what the spark tester looks like and explain how it works , i have never used one , so i dont even know what to look for at the auto parts ....

 

[ezeke]

Re: Motot starts then quits .....any suggestions ?

Just out if curiousity , does anyone know what the spark tester looks like and explain how it works , i have never used one , so i dont even know what to look for at the auto parts ....

Several options here: http://www.iboats.com/Boat-Parts-Ac...**********.090736554--submit.x.35--submit.y.7

 

[jonesg]

Re: Motot starts then quits .....any suggestions ?

Just out if curiousity , does anyone know what the spark tester looks like and explain how it works , i have never used one , so i dont even know what to look for at the auto parts ....

Ask them for an adjustable spark tester, it must be adjustable.
Paid $12 for mine , there are cheaper ones too.
Don't get the neon type, they're not adjustable and you need that big gap.

You can get carb kits here on iBoats, around $22 per carb, its straightfwd, clear the jets with wire. They usually include extra parts for a multitude of carb models so just replace what you remove from yours and ignore the extra gaskets.

Whilst you're ordering parts get some drain screw seals for the gear oil drain, change the gear oil out and be sure to install new seals on the 2 screws.
http://www.youtube.com/watch?v=Wj0l...E7DFA5BD1&playnext=1&playnext_from=PL&index=5
Walmart sells gear oil and the little pumps.

You're running the engine on a water hose ....right?
Otherwise you need a water pump impellor, no biggie though.

 

[ezeke]

Re: Motot starts then quits .....any suggestions ?

That film is appropriate to that type of Mercury gearcase but not for most OMC/BRP gearcases. This one is better: http://www.youtube.com/watch?v=JgX1Q6bkVoA&feature=related

Note that you always fill from the bottom (drain), not the top (vent), and that when filling the motor should be in the running position, not tilted.

 

[OneLuv1979]

Re: Motot starts then quits .....any suggestions ?

OK problem is spark , i used a spark tester with a lil light and it barley lights it up , im looking to order a power pack and coil , but Iboats does not have the power pack in stock , anyone know what a power pack would run thru my local johnson dealer just to give me a idea ...

The lower unit has a issue as there is oil running out the prop area and down the lower unit , pulled the screw and there is water in it ...
I plan on having my local mechanic pressure test the lower unit and replace the water pump once i get the beast running ......

Do you guys think power pack and coil is where i should start ??
Appreciate the help ....

 

[OneLuv1979]

Re: Motot starts then quits .....any suggestions ?

pack or coil ? any suggestions ?

 

[tashasdaddy]

Re: Motot starts then quits .....any suggestions ?

"i used a spark tester with a lil light and it barley lights it up". this really is not accurate, you really need an adjustable spark tester, and set it at 1/2-7/16 inch.

 

[OneLuv1979]

Re: Motot starts then quits .....any suggestions ?

It 100% is acurate , the spark was weak i know that for sure from the tester ....... When there is good spark you see the spark and the light shines bright , this was a dull light and no spark , no way in hell is that anough spark to ignite under compression ....

Just curious what step would you take , im thinking of buying a coil tomorrow and trying that , since its cheaper then a power pack ....

What ya think ?

 

[ezeke]

Re: Motot starts then quits .....any suggestions ?

Using a fully charged powerful battery, check for spark with all of the plugs out and grounded. This will insure that the engine is turning the required 300 RPM for the ignition to work properly.

Should jump a minimum of 3/8" tester gap with a bright snappy blue spark.

I would like to direct you to the ignition troubleshooting section that is correct for your motor so that you don't waste money on parts that you don't need; what's the model number? The one you gave at the beginning of the thread is not correct.

 

[OneLuv1979]

Re: Motot starts then quits .....any suggestions ?

per the motor J115plsps

I am sure the spark is weak .....what would my next step be ?