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OH NO! Failed Timing Belt Pulley! 2003 BF225

R

rsamsel

Contributing Member
Hello all-

2003 BF225
950 hrs

After a great day of fishing I was headed home at 30 mph when a terrible noise started. Immediately shut the boat off. Went back and pulled the cowl to assess the noise. I didn't see anything odd so I started it. Wife and I immediately determined it to be the outside of the idler pulley separated from its base. Shut the boat off (it should be noted it seemed to be running great.). We got a tow home and now it's time to fix. I have the motor apart and the idler pulleys off.

Here's my questions:
1. Can I turn the motor over with wrenches now or do I still risk interference damage if I start turning things
2. I need to set the timing to crank mark and mark 1 and mark 1 on the cams right? My problem is every walkthrough I see tells me not to let the timing move when changing the parts. My timing is off. Where do I need to set things so it is safe to start spinning the crank and cams to get them to line up on the marks?
3. Do I need to remove the balancer on the crank in order to see the timing marks on the crank? I know that is a special tool and very tight....I was hoping to not have to remove it.

My plan is to order the one pulley that failed....idler pulley B. Once replaced and timed I will reassemble and run the motor. If it survived this mess then I will go back in and replace the other pulleys and the belt itself.

My biggest fear is messing it up trying to get it timed and hurt it if it isn't already hurt.

Help!

Thank you,
Rob
Kent, WA
 
Hi Rob,

Sorry you're having troubles.
You might want to hear from chawk_man or ian6766 on this before proceeding. Those guys are very knowledgeable about this outboard model.

I have no first hand experience with this engine nor do I have the requisite service info for attempting this repair.

I just wanted to say that you could loosen the rocker shafts on both heads to eliminate the possibility of a valve opening and "kissing a piston" if the crank OR cams were turned.
It's a pretty standard thing to do in cases like this with pretty much any overhead valve engine.

With the rocker shafts loose or removed so that no valves can be actuated you can turn to your heart's content.

THAT IS THOUGH...if all the valves are fully closed. If you do have valves hanging open for some reason then you're probably going to need to pull that head and investigate.

With the rockers backed off it makes identifying a stuck valve fairly easy by visual inspection, use of a straight edge or measuring the stem heights.

Do you know what rpm the engine was turning when the failure occurred? I ask because, if under 4500, it's likely the VTEC wasn't activated. So, the valves would not have been fully extended at the time. If that's the case, I don't think it could bend a valve.

And, you may still be in the clear because lots of "interference" engines jump time and still don't bend valves.

Just my opinion.

I hope you can get it sorted out without too much cost or grief.

Good luck.
 
jgmo said:
Hi Rob,

Sorry you're having troubles.
You might want to hear from chawk_man or ian6766 on this before proceeding. Those guys are very knowledgeable about this outboard model.

I have no first hand experience with this engine nor do I have the requisite service info for attempting this repair.

I just wanted to say that you could loosen the rocker shafts on both heads to eliminate the possibility of a valve opening and "kissing a piston" if the crank OR cams were turned.
It's a pretty standard thing to do in cases like this with pretty much any overhead valve engine.

With the rocker shafts loose or removed so that no valves can be actuated you can turn to your heart's content.

THAT IS THOUGH...if all the valves are fully closed. If you do have valves hanging open for some reason then you're probably going to need to pull that head and investigate.

With the rockers backed off it makes identifying a stuck valve fairly easy by visual inspection, use of a straight edge or measuring the stem heights.

Do you know what rpm the engine was turning when the failure occurred? I ask because, if under 4500, it's likely the VTEC wasn't activated. So, the valves would not have been fully extended at the time. If that's the case, I don't think it could bend a valve.

And, you may still be in the clear because lots of "interference" engines jump time and still don't bend valves.

Just my opinion.

I hope you can get it sorted out without too much cost or grief.

Good luck.
Click to expand...
Yes. I have had chawk_man help me in the past. He is a genius with this 225. Its rather incredible.

I think I was under 4500 rpm. Also when I fired to assess where the noise was coming from it started immediately and other than a bad pulley noise it sounded healthy. Also, It may have jumped timing after disassembly. I got in too big of a hurry and removed the bad pulley before I checked the timing marks. I think there is a chance it held timing until I let the belt go completely slack.

As for removing the rocker shafts....I pull the valve covers obviously. Is removing the shafts straight forward? I guess my concern would be removing them and then having to get the valves compressed again to reinstall them. I don't affect the adjustment when I remove them right?

This is a scary deal for me. I boat on a budget and blowing a motor would blow my budget (as it likely would many).

Thank you,
Rob
 
Well, it would be scary for me too but that's a good thing. It slows you down and makes you cautious.....hopefully.

As far as my knowledge about loosening the rocker shafts, I only know what I read and my experience with other engines....mostly cars and diesel trucks.

It looks very "straightforward" with each shaft being held by 6 hex head bolts. But, you need to loosen each one slowly and evenly with all the rest. Just as you would loosen or tighten head bolts.

No, the valve adjustments shouldn't change but checking/adjusting them after reassembly is something that should be done.

The main thing to watch for if you remove the shafts and rockers as an assembly is making sure the rocker arms don't slide off the shaft and get damaged. That and keeping everything clean.

I'm not saying that you SHOULD do this "procedure". There may be an easier method I'm not aware of. Which goes back to getting all the info you can before jumping in.

I just wanted to offer you something you could do that would likely work since you were worried about turning the engine to line things up.

I still think you might want to hear from those other guys on the subject before diving in to something you're so unfamiliar with. I know I would ask them questions if it were me and I've actually rebuilt many engines.

And, if you're not working with an authorized service manual, I strongly suggest you get one and read up. It is a MUST HAVE for doing something like this on that very sweet and expensive outboard.
 
jgmo said:
Well, it would be scary for me too but that's a good thing. It slows you down and makes you cautious.....hopefully.

As far as my knowledge about loosening the rocker shafts, I only know what I read and my experience with other engines....mostly cars and diesel trucks.

It looks very "straightforward" with each shaft being held by 6 hex head bolts. But, you need to loosen each one slowly and evenly with all the rest. Just as you would loosen or tighten head bolts.

No, the valve adjustments shouldn't change but checking/adjusting them after reassembly is something that should be done.

The main thing to watch for if you remove the shafts and rockers as an assembly is making sure the rocker arms don't slide off the shaft and get damaged. That and keeping everything clean.

I'm not saying that you SHOULD do this "procedure". There may be an easier method I'm not aware of. Which goes back to getting all the info you can before jumping in.

I just wanted to offer you something you could do that would likely work since you were worried about turning the engine to line things up.

I still think you might want to hear from those other guys on the subject before diving in to something you're so unfamiliar with. I know I would ask them questions if it were me and I've actually rebuilt many engines.

And, if you're not working with an authorized service manual, I strongly suggest you get one and read up. It is a MUST HAVE for doing something like this on that very sweet and expensive outboard.
Click to expand...
Yeah I have a digital copy of the service manual but it feels like the instructions all assume I'm just doing maintenance and I can't find the info on how to set from an initial unknown timing starting point. Boats are a pain. :-/
 
Yeah, I have never been fond of the way Honda SI is laid out but I do prefer the paper manuals over the online stuff I've gotten hold of.

Boats are WONDERFUL....until they aren't:unsure:
 
Just back off all the rocker adjusting screws, no need to loosen the rocker shafts. Reassemble then adjust valve clearance. Then compression test
 
Your going to need some tools to get the balancer off, a 19mm socket and a breaker bar at least 1/2" drive. also you will need a balancer holding tool, the Betool works good, you can get on Amazon for $20. An air impact gun with a special high torque19mm harmonic balancer socket works better if you have the impact gun, that balancer bolt is super tight.
 
I can't add anything to what JGMO, Ian6766, and 123jayyyy posted. Just take it slow and easy - think through what you plan to do before doing it. If you are really lucky, you will get a good compression test upon reassembly.
 
123jayyyy said:
If it was running fine when the pulley broke there is no need to adjust the valves, not being experienced doing valve adjustments you could unnecessarily cause an issue. Replace all three timing belt pulleys and the timing belt, the instructions are in here in chapters 3 and 6. https://planbmarine.com/wp-content/...ice-workshop-and-repair-BF175A-BF200A-BF2.pdf
Click to expand...
The problem is all the instructions refer to KEEPING the marks at 1 1 and 1. My problem is I'm not at 1 1 and 1 and I need to get there. What position can I safely have the crank in in order to spin the cams to the 1-TDC position?
 
chawk_man said:
I can't add anything to what JGMO, Ian6766, and 123jayyyy posted. Just take it slow and easy - think through what you plan to do before doing it. If you are really lucky, you will get a good compression test upon reassembly.
Click to expand...
The problem is all the instructions refer to KEEPING the marks at 1 1 and 1. My problem is I'm not at 1 1 and 1 and I need to get there. What position can I safely have the crank in in order to spin the cams to the 1-TDC position?
 
If your motor idled fine after the pulley broke it didn't change the timing. With the plastic covers off each cam timing belt gear and all the sparkplugs removed turn the crankshaft clockwise until the notches on the balancer or the dot on the crankshaft timing belt gear align with there marks. The crank turns 2 revolutions for 1 revolution of the cams, you might have to go 2 complete revolutions of the crank to get both cam gears on there number one mark, and the marks on the crank lined up. While turning the crank, stop if you feel any binding or excessive force needed to turn the crank bolt, if this happens you'll have to remove the heads.
 
ITS FIXED!!!! Well I had a huge sigh of relief on Saturday. Boat is fixed and running great.

A friend borrowed a high quality borescope and we looked in each hole. All looked good. We then carefully spun the crank to TDC followed by the cams to the timing marks. We anticipated having to use the scope to walk past interference issues but no. We simply spun them and never had any resistance.

I replaced the bearing that got eaten up and quickly reassembled. It started perfectly and sounded and ran perfectly. Whew!

I have now placed an expensive order on ALL the components on the top side. Pulleys/bearings/bolts etc. I'm not going to run it until I get those new parts on but that will be an easy job now that it's timed. If one thing fails something else is close behind.

Looking back I should have recognized a supercharger sounding buzz from under the cowl as a failing bearing. I hadn't owned to motor long enough to know but that sound is definitely gone with the new bearing.

Thank you guys for your help!
Rob
 
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