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2008 BF8A - Pull Head Without Removing Entire Engine?

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Oceannavigator

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I'm getting deep into a Honda BF8A that has water leaking into the lower cylinder.

I don't have a flywheel puller aboard my boat. I'd also like to get somewhere (pull the head at least), without draining the crankcase oil.

Can I pull the head without removing the engine from the outboard?

The only thing holding me up is possibly the exhaust manifold/pipe.

The head moves, pops free of the gasket, but isn't moving much or coming all the way off.

It's connected to the exhaust, which can't be removed, as the lower cowling is in the way.

Does this exhaust tube slide out of the lower unit if I get the head free, or is it holding the head in place?

I don't want to break it...
 
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Not sure on the newer motors.----On older motors the head would come off without having to remove the entire engine.
 
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racerone said:
Not sure on the newer motors.----On older motors the head would come off without having to remove the entire engine.
Click to expand...


Thanks.

It's at least a reasonable guess the newer ones might be the same.

Did the long exhaust tube vanishing down into the lower unit just slide out on the older models?
 
Got it. The head gasket seems to have been the problem too, since it was a little wet when I pulled the head. Project going well. Ordering new head gasket now.
 
This site only has certain aftermarket parts for Honda.

When you are looking for the part....your motor is a BF8D.. not a BF8A, if it is truly a 2008.

The part number you are looking for is 12251-ZW9-003. It is the same head gasket for the 8 and 9.9 from 2001 on.

You could either google the part or go to boats.net.

Mike
 
Finally got the new head gasket after ordering it Jan 16th (iboats is terrible).

Need a little pep talk.

Tightening the head bolts and scared to death they will strip/snap.

46ft lbs is the spec from the manual.

That's 552 on my torque wrench in inch lbs.

I'm currently just trying to get them to 480 and I'm completely scared out of my mind. They seem soooo far past how tight anything should be.

Is this normal?

Feeling like they just keep turning and turning without giving any more resistance.

Feeling like my brand new torque wrench is defective. ha ha

I'm ok to just keep on going?

Last time I had a head off, I was rebuilding an air cooled atv engine as a child. It's been a while and I'm sure I didn't tighten the head to this extent...
 
STOP !!---All you are doing is stripping the threads out of the block.---Recheck your manual.-------Those values are way too high for head bolts !!
 
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Remember....your motor is an 8D not an 8A. There are no specs on that page for your motor.

The NM amount is correct for the 8A but must have been a typo....since the 8 A is 16 ft lb.

Raceone is correct on the long bolts 20 ft lb for your 8D. The short bolts are 17 ft lb.

Mike
 
This is confusing.

I can't tell what motor it is.

I swear it said BF8A on it when I bought it.

It's worn away now.

There is a 2008 service sticker on it from when it came from the factory not idling. In fact, I see an old thread here of mine from 2008 talking about it under a different username. It was a BF8A back then before the label wore off, so I think I'm right about the model. Think maybe I bought a leftover 2007.

I got a good deal.

What should I do now?

You guys who work on these things say 20. Manual says 46. Look at what the manual says for the 2hp. 70-100!

I'm pretty stuck.

Opinions?

How to proceed from here?
 
l=83mm m8x1.25 is 26N-m og 20 ibf-ft.
l=40mm m8x1.25 is 24 N-m or 17 ibf-ft.
remember to oil the threads, I hope you stopped in time & your threads are ok.
 

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If you have over torqued im afraid even if the threads are still ok you have squashed your new head gasket & need to replace it again with the correct torque. I would not run the motor over torqued as it is, as the expansion as it heats up could crack either your block or the head. I would release the pressure of the head bolts but that means your gasket is done in.
Sorry for the bad news. but at least its still fixable.

Dean.
 
I went outside in the dark just now and loosened the bolts.

It took 2 weeks to get this gasket and I have had to row ashore daily more than a mile this entire time. Ugh. Such a disaster.

Than you all very much for your help.

Since the gasket is crushed, I will torque to the proper amout to see if the threads are ok. If they are, I will try to find a gasket more quickly and fix.

If the threads are stripped, I will tie it to my neck and throw it overboard. ;) ha ha ha

I suppose it will be time for a new outboard in that case.
 
If (and hopefully the threads are ok) I would recommend boats.net next time around. Most here are very happy with them. I'm just guessing but if the threads are done in, if there is enough meat on the head and block you may be able to bore them out to a 10mm. But that's a workshop job not one for on the water.
Anyway best of luck.
Dean.
 
If you ordered the part number I listed in an earlier thread is the one you ordered and if it is the correct one, then the motor is a D model. It only fits the D model 8's and 9.9's.

Is there a serial number on the frame....sometimes on the side of the mount frame.....sometimes on the mount frame on the front of the engine under the steering arm.

If the serial number starts with BZBC, it is an 8A. If it starts with BAAJ, it is an 8D.

If you can not find the serial number, post a picture of the motor....that will tell us for sure.

Mike
 
Maybe this will make it easier.....

Does it look like this? 8D
BF8-9.9.png


Or does it look like this? 8A

hqdefault.jpg


Mike
 
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There is no question about the model. It's a BF8A (with really dodgy head bolts now).

I didn't even know the BF8D model number existed until this thread. Only know my own engine, not the full line of Honda's.

BZBC serial #, bottom pic.

The model and other information used to be on the side, but it wore off.. the BZBC serial number is on the centerline under the carrying handle on a metal plate.
 
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Since it is an 8A, the number I gave you for head gasket is wrong. Hopefully, you ordered it by serial number. The gasket number should have been 12251-881-003. Check the threads on the bolts...if stretched, you might have to buy new bolts.

This is a repeat....but torque to 16 ft lb.

Mike
 
hondadude said:
Since it is an 8A, the number I gave you for head gasket is wrong. Hopefully, you ordered it by serial number. The gasket number should have been 12251-881-003. Check the threads on the bolts...if stretched, you might have to buy new bolts.

This is a repeat....but torque to 16 ft lb.

Mike
Click to expand...


Thanks, Mike.

Appreciate you having looked up the part # for me. Above and beyond.

I had already looked it up and ordered the right one (then crushed it).

You guys aren't kidding about boats.net. The new gasket to replace the one I crushed will be here tomorrow (ordered it today)! After I had waited weeks for it through iboats.

The bolts are taking the proper torque just fine and after pulling them, there is no thread damage or metal shavings.

Got very lucky there.

These were torqued 2x tighter than they should have been by the time I got too scared to go tighter.

All is well after quite a scare.

Let's now hope the diagnosis was correct and the head gasket was the reason water was entering the lower cylinder. :/
 
**** you are lucky. That just shows what a quality block those older blocks are. 2x over torqued I wince while writing it.
 
I did not see mention of it so it may not apply to BF8A, but I run the 1986 grandfather of the BF8A and there is an important 'O' Ring that gets installed with head gasket. If this is not properly installed, it can result in water in your oil. As it seals the oil passage from block into head for cam and valve train lubrication.

You do have to watch for typos or errors in Service Manuals, especially torque values where they give them in Nm, KGM and Ft/Lb values. My Torque Wrench is an old Bar type that is not precise enough for small readings. I usually use a fish scale and a known arm length to convert for a shorter wrench, for example 22 Ft/Lb becomes a 44 Lb reading with fish scale moving a six inch wrench.

Hope that your great little engine saves you from all that rowing for a long time to come.
Art
 
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