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Honda BF 75

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pmeyers

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"I just bought an older sailbo

"I just bought an older sailboat which came with a 1979 BF75 7.5 p motor. The motor spits a little water when at idle, and the stream increases at higher rpm, but the water get very hot, so I am assuming it needs a water pump.
I started to remove the lower end to look at the pump assembly so I can order the right pump but I can't seem to remove it completely, feels like the gear shift shaft must be discconnected somehow. Any trick to this? Do I need to open the pump housing get the seperate the bottom end?I am ordering a manual, but would like to get a head start on getting the impeller order."
 
"Place it in forward gear, as

"Place it in forward gear, as this raises the shift link for easier access.

Remove the 6mm bolt holding the finned charging diode/rectifier, again for access.

You now first remove the cotter pin and then slide the 5mm clevis pin from the shift lever fork.

Installation is the reverse and as long as the adjustment link at the top of the shift rod is not turned,
no adjustment needed.

Caution for dropping the cotter or clevis pins.
"
 
"Save yourself some aggrevatio

"Save yourself some aggrevation and change the T'stat while you are at it. You'll have to order new intake manifold gaskets as well.
If the engine was used in salt water, you'll find a fair amount of salt deposits in there.

Re: the shift lever. There is a clevis screwed onto the end of the shifter shaft at the top that needs removed. To do this, remove the roller for the detent mechanism and then you'll be able to get the clevis pin out that connects the clevis to detent sector. Then you'll be able to unscrew the clevis itself.

Another thing worth doing is to rebuild the carb since you'll have it off when you do the T'stat.

That will take care of most of the problem spots on this engine. My BF75 (long shaft) drives my 22ft Bristol sailboat quite nicely. Very smooth and quiet... uses next to no gas. Coming back into the marina, I disconnect the fuel line when I'm about 50 yards away from the slip and the engine runs on the fuel in the bowl until I get the boat into the slip and tied up."
 
"You can find the zoomable dra

"You can find the zoomable drawings and parts at:

http://www.boats.net/parts/search/Honda/Outboard%20Engine/0/parts.html

When I ordered those manifold gaskets, ship invoice said "not available"
and a toll-free call found that those gasket p/n's ending in >...850 need changed to >...003.

They also have new carburetors and some parts, but rebuild kits do not exist for them,
just do a THOROUGH cleaning, but avoid 'soaking' body in carb cleaner.

Thermostat should not corrode, first try cleaning and then you can test its opening with a candy thermometer.

No need to unscrew that shift shaft clevis (and lose adjustment) as it will slide out with the rod
when you drop the gear case.

Your idea of getting yourself the Honda Shop Manual is excellent.
"
 
Thank you for your help!
I go

Thank you for your help!
I got the impeller and the thermostat out and got everything ordered; including a manual. A lot of white corrosion in the thermostat housing and the thermostat looked like it was shot. I broke it getting it out it was stuck so badly. Thanks again..
 
"Make sure that all the mating

"Make sure that all the mating surfaces are cleaned of any old gasket material (or sealant). You may find that the seat of the T'stat will need some "rehabilitation". Also.. invest in a tap for that bolt size ( #6 Metric I think) and using some WD40 as lube, clean out all the threaded holes in the block... and THEN..MOST IMPORTANT... use a torque wrench to tighten the bolts whenyou put it back togather. Make sure all the bolts will run easily all the way in under finger pressure before reassembling it. Use a strip of paper towel twisted to fit all the way into the hole to wick out any residual WD40 before torquing bolts down."
 
"+++ on the thread

"+++ on the thread cleaning advice above +++


When I could not find a 6mm 'blind' tap, I just ground off most of the pointy end of a regular 6mm tap.

(Assemble with 'NeverSeize' and Torque spec calls for 7 ft/lbs.)"
 
"Pilotart...thnx... forgot to

"Pilotart...thnx... forgot to specify a "blind tap"... very important...
Also, if you've never used a tap to clear blind threads... recommended procedure:
Using the "T" handle...
Squirt some WD40 on the tap
Carefully start the tap in the hole.
1)Turn CW using finger tip pressure only until it just starts to bind.
2)Turn CCW 1/4 turn
3)Turn CW 1/2 turn
4)Remove tap and clean crap off of it.
5)respray w/WD40
6) Repeat steps 1 to 5 until tap bottoms.
Clean tap and wick out any WD40 in the hole.

Its a bit tedious, but goes fairly fast. Beats doing the Helicoil insert drill.

Also... wirebrush the threads on the bolts to make sure they are squeeky clean. If damaged you may have to "chase" the threads with a threading die."
 
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