johnson 90hp v4

[bayliner1972]

I have resently bought myself a secondhand bayliner mosquito with a johnson 90hp v4 outboard. The thing is that the motor keeps flooding and have petrol seeping out the lower carb. Futher more, the engine doest sound to healthy at the moment. When i do get the engine running it starts leaking oil via the prop. Could anybody tell me what the problem could be. I have just spent the last of my savings to buy the boat and I would first like to solve the problem myself.<br /><br />Regards<br />Kevin

 

[DJ]

Re: johnson 90hp v4

Kevin,<br /><br />Two things to do fist. Emphasis on #1.<br /><br />1. Check the compression. If all cylinders are NOT within 5-10 psi of each other, your problems are deep.<br /><br />2. Rebuild both carbs.

 

[bayliner1972]

Re: johnson 90hp v4

Thanks for the quik reply..<br /><br />How can i check the psi myself seeing that i dont have the profesional tools. Is their a simple way on doing this<br /><br />Kevin

 

[Cricket Too]

Re: johnson 90hp v4

Welcome to iboats. Sounds like the float is stuck on that lower carb leaving the needle open, they should be pulled and rebuilt. How much oil are you talking out of the prop, if it's just a little puddle then it's probably just 2 stroke running down after you shut down.

 

[onebohemian]

Re: johnson 90hp v4

Oil out the prop could be lower unit fluid but is more likely unburnt gas/oil running through the exhaust. Sounds like a carb rebuild or at least some maintenance is in order. Good luck.

 

[Cricket Too]

Re: johnson 90hp v4

You will need a compression gauge to check compression. You can get one at any auto parts store, or Sears if you have them over there.

 

[bayliner1972]

Re: johnson 90hp v4

the oil running down seeps out slowly for about 5 minutes after the motor has shut down. it is mixed I think with fuel. Is it the needle problem in my carb that is causing the motor to flood ??<br /><br />Kevin

 

[mulv80]

Re: johnson 90hp v4

Rebuild the carbs. Most likely you have some debris which is not allowing the needle to seal properly in its seat. Rebuiding carbs is a piece of cake, but shouldnt be tackled without a manual. So order a couple of carb rebuild kits and a manual. The oil from the prop is most likely unburnt fuel oil mix and is normal.

 

[DJ]

Re: johnson 90hp v4

Compression guages are CHEAP and readily available.<br /><br />Without good compression on all four cylinders, you're trying to revive a dead engine.

 

[CATransplant]

Re: johnson 90hp v4

Well, if the engine is flooding, it won't sound too good when it runs. It will idle very poorly and might not run at high speeds well, either.<br /><br />Perhaps you can borrow a compression gauge at the place where you get automotive repairs or from a friend who works on engines. They are not expensive, and you really should check the compression on all cylinders before spending any more money on this engine.<br /><br />If the compression on all cylinders is within 15% of each other, you should be all right.<br /><br />Then, rebuilding the carburetors is in order for this motor. You'll definitely need a manual for this job, especially if you are not experienced in such things.<br /><br />One thing is certain, if you have purchased an older, used boat, you will be spending more money before you are on the water and happy. That is inevitable.

 

[bayliner1972]

Re: johnson 90hp v4

I have just tested the compression seeing that my neigbour has a pressure gage.. All 4 the cylinders gave out 8.1 psi<br /><br />I am now going to try and get the carbs off and clean them. I hope this will solve my problems

 

[reeldutch]

Re: johnson 90hp v4

hoi kevin,<br /><br />je compressie moet rond de 100 psi liggen en mag niet meer dan 15 psi onderling verschillen.<br /><br />(sorry i couldnt resist talking dutch to my fellow dutch friend.<br /><br />check the float and also your primer.<br />if you would like to email me i can send you a whole lot of info and i will explain it in dutch.

 

[DJ]

Re: johnson 90hp v4

Kevin,<br /><br />I'm a little rusty on the conversion. The IMPORTANT point is that they are all close to each other and appear to be healthy.<br /><br />Your next line of attack is the carburetors, as reeldutch suggested.

 

[CATransplant]

Re: johnson 90hp v4

I think those are kiloPascals, divided by 100, on that metric compression gauge. If so, then his compression is fine.<br /><br />Sounds like carburetion.

 

[CATransplant]

Re: johnson 90hp v4

Converts to about 115 psi or so.

 

[reeldutch]

Re: johnson 90hp v4

yep that sounds european.<br /><br />i would overhaul the carbs and level the floats.<br />check the primer.<br />what type of fuel end 2 stroke outboard oil are you using and was this motor not used for a while?<br />did they put fuel stabalizer in the tank?<br />put water fuel seperater and a new inline fuelfilter on your motor. before you put you spik and span overhauled carburator back on the intake.<br /><br />veel geluk ermee

 

[bayliner1972]

Re: johnson 90hp v4

Hallo reeldutch..<br /><br />Ik heb net de onderste cabarateur eraf gehaald,schoongemaakt en er weer op gezet. Motor loot verlopig wel een stuk gezonder. Morgen haal ik de bovenste eraf en doe ik daar het zelfde mee. Waar woon jij precies. Zo te horen heb je er best veel verstand van. Mischien dat ik je een keer kan bellen als dat mag. Mijn email is kevinlangenberg@hotmail.com<br /><br />Groetjes

 

[bayliner1972]

Re: johnson 90hp v4

Can anybody tell me what that electronic gadget is that is fitted to the top of the intake manifold. It is a round device with what looks like a red tap on it that you can turn.

 

[Dhadley]

Re: johnson 90hp v4

Thats where the other 50 horsepower is kept. Dont turn that knob until youre ready to race.<br /><br />Sorry! Cant help it, long day. Thats the primer solenoid. It repalces the old choke system.