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2006 honda 90hp

B

baystealth07

Member
i have a 2006 90hp honda that i am having problems with. the motor starts ok and idles fine but when i give it the gas it sputters and wants to die. i have changed the water fuel seperator and cleaned the fuel filter and checked the plugs and nothing seems to help. i am going to check the 2 fuel pumps tomorrow and see if there is a problem there. is there anything else i can try or test? it has fresh gas and i have added sea foam to it. i can choke it several times and then it will get up and go. it also runs fine at wot. any suggestions?
 
I did not know that the 90 HP had a cleanable fuel filter. I thought it was not serviceable.

From you description of how the motor is operating...

Most likely the transition ports are clogged on one or more of the carburators. They provide additional after the carburator leaves the idle state and before it gets to full throttle. They are a series of small pin size holes at the top rear of the inside of the carburators.
If anything is going though them now, the Sea Foam might help to clean them out. If not, the carbs have to come off and be cleaned.

Could also have cracks in one or more of the idle jets.

The carbs not being vacuum balanced can also affect the acceleration. Rough idle is where imbalanced carbs are normally first noticed.

Your diaphram assembly may be not working or out of adjustment. It is part #2. http://www.boats.net/parts/search/H...RTA VIN# BBBL-4800001/THROTTLE CAM/parts.html
It helps with acceleration and deacceleration. If you gently push up on the end of the rod while the motor is idling, the motor speed will increase. That is not exactly the book test, but if it does not do anything to the motor, then you know you are in the right area.

Those are the most likely problems...although there are a lot of other things that can be checked.

Mike
 
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the fuel filter is not serviceable on this honda. i just blew it out with low pressure air. well since then i have replaced the filter to be on safe side. also as an elimenator i changed the plugs to a set of ngk plugs and at that time i noticed that the bottom cylinder plug was blackish and the oters were a normal color of a firing plug. i was told by a mech. that the cylinder with the dark plug was probably not getting any fuel to it. i pulled the carbs and intake and just cleaned the one carb. i know i should have cleaned all of them and i may take them back off to do just that. i havent run it yet to see if i fixed the problem. will run it on the 30th tomorrow. any idas on why that particular plug might not be firing? i checked the plug wire with ascrewdriver to the block and i do have fire to it. i know these carb. engines are normally cold blooded at times but this problem started after sitting up for almost three months. anywy the one carb i did clean seemed to have some pliuged holes as you mentioned. it had a set before the butterfly and a set after it. if the plugs in the other cylinders looked good then shouldnt those carbs be workig properly? i am going to check that diaphram thing tomorrow also. thanks for the info so far
 
also i heard a kind of hissing sound at times when the motor was running. it only did it every so many seconds. the motor idles perfectly and is not rough at all. could it run on 3 cylinders like that?
 
Idling perfectly is different to different people.

While it is idling...momentarily pull the plug wire from each spark plug and see if there is any drop in the engine speed. Use insulated pliers.

If all the cylinders drop the same amount, they are all firing ok (at least at idle). That says nothing of the other passages.

In general, the bottom carb gets clogged before the others....the fuel settles there.

The black plug means more that it may be getting too much fuel or misfiring.

One other thing to check...pull off the bottom fuel pump and squeeze the bulb until it is hard. Make sure it is not leaking. Do not disconnect any of the hoses. Just check the plunger. Push the plunger in as an added check for leaks.

Hope the one carb did it. Normally, I see if one is bad, the others are not far behind.

Mike
 
what would cause a misfire in the bottom cylinder? i have started it and pulled the plug wires one by one and the motor changed with the top three but not the bottom cylinder. i have since changed the plugs and cleaned the bottom carb. i am fixing to go check a few things now. ok i just checked the plug wire on bottom cylinder. i started it and when i pulled the wire the rpms seem to change and then i checked the diaphram thing and when i pushed the rod up the motor reved up a bit. are these good things?
 
i amgoing to take it out tomorrow and see how it does. i havent checked the fuel pump out though. i will let you know how it runs. i do really appreciate all the help and advice though. you have been a big help
 
how are you today mike? well i too the boat out today and the damn thing still wont run at mid throttle. i can pull manuel choke half out and then it will take off ok. i checked the bottome cylinder to see if it was still firing and it was. am i looking at taking the carbs back off again? what kind of cleaner do you recommend for cleaning th carbs real good? i am just going to do all carbs this time, but one at a time. anything else i can try before i get this drastic?
 
You should always first check compression...to be sure that your cylinders are ok.

Then remove the fuel pumps and check for leaks. If none found, then you will need to go through all of the carbs.

I usually use an ultrasonic cleaner and just use brake clean to shoot through the passages to be sure that they are all clear. Then blow out with compressed air.

Mike
 
where could i get a compression gauge for this honda motor? and what should the compression be on this 2006 90hp motor? i will check the fuel pump tomorrow actually i will check both to be sure they r not leaking. i have an ultra sonic cleaner at work i can use. is it safe for all carb parts? i did use brake clean and air when i did the bottom carb an i checked for cracks on the main jet, none found. i also looked at the float needle and it looked new from under a manifying glass. what all would come in the carb kits or what do i need to replace on them?
 
The ultrasonic cleaner is just water with a solution (somewhat like soap - but special solution). It will not harm anything on the carbs.

There are no carb kits for the Hondas. You have to order parts individually. Whenever I have one that is really bad, I replace the idle jets, needle, and o ring set.

Do not know where you live, but you can probably get an inexpensive I do not know where you live...but Harbor Freight carries a cheap gauge http://www.harborfreight.com/compression-test-kit-66216.html There are probably several that you can find on the internet. It has to be able to fit in the 12mm spark plug hole.

When you take the compression, you should have the throttle (not in gear) advanced all the way to full throttle. Disconnect the safety landyard to kill the spark. Have all of the spark plugs out. Compression should be 212 plus/minus 14 psi

I do not know how you have taken the carbs off, but the book says to take them all off as a set with the intake manifold. If you did that, be sure that you clean the surface really good and replace the intake manifold gasket. If you just reused the old one or did not clean the surface very well, you may be getting water in the cylinders for the water passages next to the intake passages on the head. If you are not removing the intake manifold, then disregard this paragraph.

Mike
 
i will get a compression gauge tomorrow and check the compression on the cylinders and also check the fuel pumops to see if they are leaking by. so i take the fuel pumps completely off the motor? and then crank the engine over? i did take all four carbs off with the intake and did clean the surfaces good and reinstalled them with a new gasket. i did see the water jackets in there. when you are saying replace the idle jets, are there only 4, 1 in each carb? and when you said needle what were you referring to? and the o-ring would be for the bowl? when i cleaned the 1 carb i saw i guess a main jet in the center then 2 other small jets i guess they were. now on that center one i took out the center tube and there was another piece in the middle o that one. how does that part cme out and should that be replaced also? where would be a good place to get these parts?
 
Leave hoses connected to the fuel pumps and just remove them from their mounting. Do not try to start the engine. Just squeeze the fuel bulb and hold pressure on it when it gets hard...as you are doing this, check the pumps for any leakage.

Number 18 is the idle jet http://www.boats.net/parts/search/Honda/Outboard%20Engine/2006/BF90A6%20LRTA%20VIN%23%20BBBL-4800001/CARBURETOR/parts.html

Number 2 is the o ring set. There are three o rings. One goes at the end of the idle jet. Just use a little screw driver and pop it out from inside the carburator throat. You should be able to see through it. It has a very small hole. Put a little oil on the o ring when you put it back in, otherwise, it may seat properly.

Number 3 is the needle. The Honda name is float valve.

Mike
 
so i shouldnt replace the number38 part? if so which one there are 3 listed. also you said there are 3 o-rings that come with the number2 and 1 goes at the end of the idle jet, where do the other 2 go?
 
when i pull the fuel pumps do i leave them assembled? or do i need to take the back off them? it seems like if i took back off when i pumped the bulb it would just blow throguh the valve inside. if i leave the back on where should i see a leak if there is one?
 
Two bolts hold on each fuel pump. Just remove the bolts and pull the pump away from the engine. Do not take it apart. Squeeze the bulb and check for leaks.

Part # 38 is the main jet. You should not have to replace it, if it is not damaged and you can clean it out. I have never changed one. There are three different ones, in case they need to be changed if you were operating your motor at a high altitude.

Make sure you clean part #39 real good too. That is the slow speed jet and helps with transition to higher speeds.

Mike





There are actually 4 part #2's. Carb bowl o ring, bowl drain screw o ring, idle mixture screw o ring, idle jet o ring.
 
i checked for leaks on both fuel pumps and did not find any, which is good. i am trying to get a compression gauge still to check for the proper compression. should the compression be close to the same on all cylinders? i have checked the valve clearances before all this other work and they were within specs and all seemed to be opening and closing. like i said before i can pull manuel choke out and then everything seems to operate like normal. is that a sign that the problem is in the carbs? i plan on cleaning and reassembling them one by one to avoid any confusion.
 
hey hondadude. i got the carbs all cleaned and rebuilt and it seems to be running better. took it out and i have a mid range throttle now. now i have a new problem i am tackling. my controls are very stiff ! i can take the cables off the motor and it is free as can be then but when i hook them up they get stiff again. i checked the linkages with the cables off and they both move but i think the cables between the linkages and the carbs are out of adjustment. is there a trick to getting these adjusted right? one of them were loose when i got the boat back from the fiberglass shop. i am scratching my head trying to figure this one out. please help!!!!
 
Yes. There are adjustments at both ends of the cables. You have to have the cables at equal tightness and a mark on the starboard side arm must align with the throttle cam roller on the bottom carburator. At the same time, the arm that you connect the throttle cable to must touch the stop at full throttle, while the cam of the bottom carburator should be at the top of the slot at full throttle.

This is where it would be very helpful to have a shop manual. It has lots of pictures and measurements. The manual I use on my computer is copy protected and can not even copy one part of a page. The adjustment is a 16 step adjustment to do it right. So, I can not send you anything.

I would try to take the slack out the of the loose cable and then check the positions of the cams and arms at full throttle. When you connect the throttle cable from the shifter, position the lever so that the cam roller on the otherside is aligned with the small arrow on the arm at the carburator.

This probably does not make a lot of sense, but might at least give you some thoughts.

Buy that manual.

Mike
 
thanks mike i will try to make some sense of it tomorrow. i do have a honda manuel for different hp motors and i will look through it again tomorrow. i did see the arrow you are talking about so i know where that is. so the cables that go from those arms over to the carbs need to be the same tightness or looseness?it sounds like you are explaining to do all this at full throttle position of the shifter, is that right? what manuel do you recommnd and where cn i get it?
 
This is the manual that I recommend. http://www.helminc.com/helm/Result.asp?Style=helm&Mfg=AHP&Make=MAR&Model=BF90&Year=&Category=1&Keyword=&Module=&selected%5Fmedia=

It shows what the measurements should be at the end of each of the cables, so everything is very close when you start.

My guess is the aftermarket book that you have does not have this detail.

You make the cable tightness adjustments at idle setting. If the throttle cable is not connected, you can operate the lever by hand to check the operation. Then you adjust the throttle cable for the proper idle position, then check for full throttle. If you do not get full throttle, then you need to make subtle adjustments.

Mike
 
i have the seloc manuel and i found in it where the measurements were. i adjusted everything like they said and the throttle was still tght, so i went and bought new cables and installed them and bam! everything seems to be good now. taking it out for a test run tomorrow. i am still concerned about the bottom cylinder because i pulled the plug wire while running and no change. checked for fire and it had just as much as the other cylinders and then i pulled plug and checked and it looked good too. the compression is about 212 in all cylinders s i dont know what is going on there. i guess i need to check the vaccum on the intake for all 4 cylinders?
 
Try this also....disconnect the plastic choke linkage rod that connects to all of the carburators. That way, when you activate the choke, you are only choking the bottom carburator.

Run the motor, then activate the choke to see if the bottom cylinder picks up. If it picks up, then you still have an issue with that carb.

Mike
 
ok i will check that tomorrow. took it out today and everything seemed to be good. i did find out that the primer bulb on the fuel line kept losing its prime and it was like the valve in the connection to the motor was sticking shut and it wouldnt let the fuel through to the carbs, banged it a little and it worked fine
 
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