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HELP Honda b75 4 stroke motor mid 1970bs I believe

dvxdude

New member
"Hi everyone. I'm having t

"Hi everyone. I'm having trouble with my motor. I just bought it with a 14' aluminum boat. It runs good, starts first pull but it seems to be leaking oil/gas. I checked the oil when I got it, he said he changed it and it looked clean and was at the full mark. I took it out for the first time and you could see the oil/gas on the water when I would stop. Not a whole lot but coming out somewhere. Now the oil is ABOVE full and smells a bit like gas. Motor still runs fine but I dont want it leaking into the water.

what do you think it could be? I took the cover off and the motor looks to be covered in a bit of oil. Just looking for a few ideas on the problems before I take it to get looked at..."
 
Along with the fuel pump (

Along with the fuel pump (Which I agree with)#080903-161-935-024 --you might have lost the bottom crank seal after it soaked in fuel for a time? #049813-91202-881-003. If you go after that you may find it a chore/ so would do the fuel pump first and see if it wants to come back to the party- It may just be passing excess crankcase oil out the hose near the pee hole. Let hope.
 
"There is a crankcase vent sys

"There is a crankcase vent system (the oil cap screws into) that sends oil vapor every where to get it back in the crankcase, Check those little hoses for leaks and the big chamber near the starter handle for leaks."
 
thx a lot guys. I have the mot

thx a lot guys. I have the motor at a friends place and hes looking at it. I'll mention these things to them. You all are a great help. Thx again
 
"Greetings Everyone,

I have


"Greetings Everyone,

I have a perfectly running Honda B75 7.5 hp. I keep it in my heated garage in the winter. The oil level never goes down, but I'm a rookie and I want to change it and don't know where I drain it at. The gas tank has the side container holding an extra bottle of unlabeled oil that I have rarely used so I don't even know what type and weight oil I'm supposed to use when I change it. I don't have a service manual. Can any of you wizards clue me in? Plus, I would like to know if there is anything else critical that I need to do at this point? It's an old ugly orange and white engine, but it has performed flawlessly for years."
 
"The drain plug is on Starboar

"The drain plug is on Starboard side just above top junction with lower leg (fat slot screw plug with gasket ring).

Recommended oil is SAE 10W-40 SE or SF or better (Marine Type preferred) and capacity is .8L or 27 fluid Oz.

Engine oil service interval is every 100 hours or six months, WOF.

Lower unit uses Hypoid 90 Gear Oil (GL4 or GL5) and capacity is .23L or half-pint. Two plugs, upper to check level and lower to drain/fill, leave upper plug out until overflow on fill (also have gasket rings to check or replace).

Service interval is 200 hours or one year, WOF and same for Spark Plugs, Theromstat and valve clearances:

IN - EX = 0.06 mm - 0.10 mm (0.002" - 0.004")

with engine cold, most recommend a little more, like 0.005".

Fuel lines and filters as well.

Remove prop, check shear-pin and for monofilament line wrap, grease shaft and replace."
 
"pilotart, Fantastic. Thank yo

"pilotart, Fantastic. Thank you for your prompt response and great info! Sincerely appreciated.

- Dennis"
 
"Dennis,

You are welcome.


"Dennis,

You are welcome. BTW it is always better to "START NEW DISCUSSION" (thread) with this type of question as it is more likely to be seen and will be more helpful for others future searches on subject.

Check my answer again, as I added a check for your propellor.
"
 
"Guys
Although the diaphram a


"Guys
Although the diaphram assigned part # from Honda is unavailable, try part # 161819935024 will work."
 
hello i also hav e a honda bf7

hello i also hav e a honda bf7.5 runs great i mean perfect but im getting water in oil a good bit and oil light flickers can you help me
 
hello i also hav e a honda bf7

hello i also hav e a honda bf7.5 runs great i mean perfect but im getting water in oil a good bit and oil light flickers can you help me please i just dont understand if its a head gasket how could it run so good. other than head gasket i dont have any idea.
 
Try checking your thermostat.

Try checking your thermostat. If the t-stat is stuck in the open position you can get condensation build up in the crankcase.
 
ok thanks i took the thermosta

ok thanks i took the thermostat out and it is stuck open and you could see where water was getting past the gasket into the egr passage but when i blow air into water passage it also comes out of small hole in head that goes into egr passage on intake manifold that doesnt seem normal to me. when you take intake manifold off and look at the head the bottom right hand bolt for intake come up one hole wher does that passage go. if you could give me an answer i would really appreciate it. thank you.
 
hello my name is jeff and i ha

hello my name is jeff and i have a honda bf 7.5 and im getting water in oil a good bit but motor runs perfect and yes my thermostat is stuck open but i think im leaking in water at plastic oil fill housing where hose comes from intake into oil fill cap housing i dont know where its suppose to go from there i think housing is leaking and do they make a new revised metal oil fill housing. ive been an auto mechanic for twenty years this is my first outboard if you could answer this one question i would be home free and really appreciate it thank you.
 
"jamfishing,

What JIT mean


"jamfishing,

What JIT meant by "start a new thread" was for you to open a new discussion.

Go back to the Topic List and click on the START NEW DISCUSSION text at the top of the column and you can start with a descriptive title in the "Subject" box.

This will greatly improve the quantity and quality of responses for your problem.
"
 
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