EFI Honda 90 help!

20dauntless

New member
I'm in Sitka and had the boat pulled for a lower unit oil change and the dealer discovered a leaky thermostat. The bigger problem is the thermostat leaks very near to the ECM and its connections. Saltwater and electronics don't mix, so I want to get this problem corrected before I leave Sitka.

Digging around a bit deeper it appears Honda issued a service bulletin about this very issue. I asked the dealer here in Sitka if there are any common problems with the BF90D, and he said there weren't any serious ones, just a problem with leaky thermostat covers. Sure enough, when they pulled the cowling off my engine, it had the same problem. Honda used a plastic thermostat cover that has a tendency to warp so the gasket no longer prevents cooling water from squirting out around the cover. I believe my engine (a 2008 model year) should have had the plastic piece replaced (the same bulletin also recommends changing from a 60 degree thermostat to a 72 degree t-stat) with a more robust metal unit, so I'm not exactly sure why two other Honda dealers haven't informed me about the issue. I also don't know why Honda can't just tell owners about these types of problems directly.

Anyway, Honda has (I think) replaced the plastic cover with a more robust metal cover. No place in Alaska has these, but I found one at Tom-n-Jerry's at Twin Bridges in Mt. Vernon. I bought it over the phone and Bill Youngsman, the owner of Twin Bridges, kindly drove it down from Twin Bridges to Shoreline (he was heading that direction anyway), where my dad picked it up, drove it to SeaTac, and gave it to Alaska Airlines to bring up tomorrow morning (major kudos to Twin Bridges, especially Randy and Bill).

The Honda dealer here wouldn't give me a print out of the service bulletin. He said he wasn't sure if he was allowed to, which was quite frustrating. He did give me the part numbers for the replacement parts and that's how I got them from Tom-n-Jerrys.

Has anyone else dealt with this issue on a Honda BF90D? Seen the service bulletin? At this point I think I have a good grasp on the issue, and hope the parts that arrive tomorrow will sort it out for good, but I'd really like to put my own eyes on the service bulletin to be sure that the parts that are being flown up tomorrow are what I really need.

I suppose I'll call Honda Marine directly tomorrow and I'll talk to EQ as well. I'm sure they'll be able to clarify.

If Honda Marine knew about this common failure before (which I strongly suspect they did) and didn't bother to inform their customers, I'm not going to be happy. I don't like spending hundreds of dollars to fix a failed $10 part that I could have preemptively replaced long ago.

If any of you have info on this I'd love to hear it, and if you have a BF90D, keep an eye out for this problem!
 
20dauntless":1kclbix2 said:
I'm in Sitka and had the boat pulled for a lower unit oil change and the dealer discovered a leaky thermostat. The bigger problem is the thermostat leaks very near to the ECM and its connections. Saltwater and electronics don't mix, so I want to get this problem corrected before I leave Sitka.

Digging around a bit deeper it appears Honda issued a service bulletin about this very issue. I asked the dealer here in Sitka if there are any common problems with the BF90D, and he said there weren't any serious ones, just a problem with leaky thermostat covers. Sure enough, when they pulled the cowling off my engine, it had the same problem. Honda used a plastic thermostat cover that has a tendency to warp so the gasket no longer prevents cooling water from squirting out around the cover. I believe my engine (a 2008 model year) should have had the plastic piece replaced (the same bulletin also recommends changing from a 60 degree thermostat to a 72 degree t-stat) with a more robust metal unit, so I'm not exactly sure why two other Honda dealers haven't informed me about the issue. I also don't know why Honda can't just tell owners about these types of problems directly.

Anyway, Honda has (I think) replaced the plastic cover with a more robust metal cover. No place in Alaska has these, but I found one at Tom-n-Jerry's at Twin Bridges in Mt. Vernon. I bought it over the phone and Bill Youngsman, the owner of Twin Bridges, kindly drove it down from Twin Bridges to Shoreline (he was heading that direction anyway), where my dad picked it up, drove it to SeaTac, and gave it to Alaska Airlines to bring up tomorrow morning (major kudos to Twin Bridges, especially Randy and Bill).

The Honda dealer here wouldn't give me a print out of the service bulletin. He said he wasn't sure if he was allowed to, which was quite frustrating. He did give me the part numbers for the replacement parts and that's how I got them from Tom-n-Jerrys.

Has anyone else dealt with this issue on a Honda BF90D? Seen the service bulletin? At this point I think I have a good grasp on the issue, and hope the parts that arrive tomorrow will sort it out for good, but I'd really like to put my own eyes on the service bulletin to be sure that the parts that are being flown up tomorrow are what I really need.

I suppose I'll call Honda Marine directly tomorrow and I'll talk to EQ as well. I'm sure they'll be able to clarify.

If Honda Marine knew about this common failure before (which I strongly suspect they did) and didn't bother to inform their customers, I'm not going to be happy. I don't like spending hundreds of dollars to fix a failed $10 part that I could have preemptively replaced long ago.

If any of you have info on this I'd love to hear it, and if you have a BF90D, keep an eye out for this problem!

You did not notice this when you checked the Oil Before :thup each trip?? It will all work out. Have a fantastic remaining trip!! :beer
 
Sam,

I found this reference. It's incomplete, but at least it may give you a clue as to what service bulletin number to look for.

Honda had a problem with water ingestion which damages the O2 sensor, if your sensor was replaced because of this you should check with your Honda Dealer, even if the engine is out of warranty. Your motor falls within the serial number group. Tell him to reference Service bulletin #56.
Some of the motors also had a thermostat cover problem, bulletin #50
. skiltch.com

Sorry to hear about you're difficulties. What a PITA. Hope you get everything sorted out in short order.
 
The leaking is hard to see without knowing where to look. It's towards the back of the engine and covered by the cage around the ECU, so unless you take that off you can't see the problem. The dealer here knew where to look.

Just got off the phone with Honda. Not very helpful. They basically said to go to a dealer. Also said they've never heard of the issue, still use the plastic cover, and never issued a service bulletin. Despite my attempts, the guy on the phone said he could not direct me to anyone with any knowledge of parts besides the local dealer.

Kathy at EQ is checking into it now. This whole thing would be dramatically less complex if Honda published service bulletins online rather than forcing everyone to go through dealers that aren't always helpful.
 
A little more update for those with BF90D's.

The troublesome thermostat cover is the one for the engine block thermostat. I don't actually have the replacement metal part yet (it's on Alaska flight 63 right now) but I'll have it this afternoon and it should be installed tomorrow AM. Hopefully it is the right part!

Here's something interesting. Boats.net has the part I need listed as 19315-ZW9-000. The local Honda dealer says this is the old plastic part. Another website has a parts diagram that lists 19315-ZY9-000 as the part I need, which is what the local dealer said is the metal replacement.

Honda Marines telephone support was totally unhelpful and couldn't tell me the difference between the parts, or which one I should have.

I just talked with Kathy at EQ and she looked up all the bulletins and didn't see one regarding this issue, nor had they seen problems in their shop.

Realistically this isn't that big a deal and the part is inexpensive. My bigger problem is if Honda really did know about the problem and didn't fix it. And getting parts up to Alaska quickly isn't all that easy!

As long as the part the dealer told me to order is really the correct one, I should have everything sorted out tomorrow AM. Not a big deal since I was already going to be in Sitka until the 15th.
 
It's ashame that the marine engine manufacturers are not required to notify the public as they are by the government regarding automobile recalls and defects. Since it could be a safety issue having your engine just stop in heavy seas etc. regardless if you checked your oil that particular morning or not.
D.D.
 
I'm confused. If you are having your boat worked on by a honda dealer is sitka and its a honda recall then why are you ordering the part and not the honda dealer?? whats the difference between a recall and service bulletin? who pays for it?
 
I can understand Sam's going around the dealer to expedite the issue.

There are a few items I carry in my "kit" these include a quasi steel epoxy, J B weld and JB weld Kwik, as well as a plastic epoxy repair. It is amazing what you can fabricate using old parts, a Dremel tool (rechargeable), and some silicone gasket material, along with an assortment of gasket material....I suspect that if you don't get the metal part, that you can fabricate some repair which will keep water off the unit.
 
starcrafttom":dcnkorw7 said:
I'm confused. If you are having your boat worked on by a honda dealer is sitka and its a honda recall then why are you ordering the part and not the honda dealer?? whats the difference between a recall and service bulletin? who pays for it?

Honda has not issued a recall. According to Honda Marine, they haven't even issued a service bulletin. The local dealer, however, says they have seen a service bulletin that , among other things, suggests that dealers swap out the plastic thermostat cover for a metal unit. I asked Honda Marine specifically about the change, and gave them part numbers for the plastic and metal parts, but they were totally useless. Just told me to go through a dealer. They didn't seem to understand the issue, or care to learn.

The local dealer couldn't tell me when they could get either the plastic or metal part, but it suggested it may have been a matter of weeks. Not wanting to wait around in Sitka until the dealer got around to helping me, I took matters into my own hands and got the part within 18 hours. Tom-n-Jerrys at Twin Bridges had it, Randy at Twin Bridges gave the part to Bill Youngsman, who owns Twin Bridges and he drove it down from Mt. Vernon to the Seattle area, my dad picked it up from Bill at his house and dropped it off at Sea-Tac last night. Alaska Airlines called me at 10 this morning and had the part in Sitka. Superb service from Alaska Air and Twin Bridges Marina. $40 all in.

My engine is out of warranty. The five year warranty started in 2010 and it ends at 250 hours anyway, I believe. I highly doubt Honda will pick up the tab, but who knows. It's not so much the issue of money that frustrates me...it's the reality that if I had been made aware of the faulty plastic thermostat cover I could have replaced it long ago or carried an extra.

Thankfully the problem never caused any loss of function of the engine and I don't anticipate any long term damage. It's just a hassle to get parts up here, especially if I were relying on the local Honda dealer and didn't have people in the Seattle area to help me out.

If you do have a Honda EFI 90, do a bit of preventative maintenance and replace the plastic tstat cover with the metal one and you should never have to deal with this problem.

All said, this problem cost me a few hundred bucks and no lost days. If this is the worst problem I face on the trip, I'll be thrilled!
 
Sorry I'm late to this discussion. As said before, I'm a Honda Marine dealer. It's late so I'll just make some random comments. Previously mentioned Ser. Bull. #50 and #56 are related to BF200 and225 engines- totally unrelated to the BF90. S.B. #73 relates to oil dilution on BF90D engines that MAY occur on certain engines, especially those apt to be operated in low water temps and at sustained low engine speeds (hull speed on a CDory?). Oil dilution must be substantially verified, and then if so, a new head gasket and tstat is available. The S.B says:

Earlier engines have a plastic thermostat cover.
This cover can get distorted by corrosion. If the
cover is distorted, replace it with an improved
aluminum type.

Repairs made under this SB outside of the warranty period, may be eligible for goodwill consideration.

There is no bulletin on the tstat cover specifically. The part # you quoted is the newer aluminum part. When we need a part, stat, Honda has an urgent part order process- we've actually received parts overnite here in Hawaii, Alaska might take a bit longer. You will pay some freight for that speed, though...
Depending on the exact date your engine was sold, it may still be under Honda's True 5 Warranty- see details here:
http://marine.honda.com/pdf/warranty/P- ... d_Warr.pdf
Honda is a great company, and believe me, they do everything possible to keep their customers happy. They are however a huge corp with a large legal department and their on-phone customer service folks are limited to how far they can get involved directly with a customer. That is why they refer you the the local dealer. It's a shame if the dealer doesn't step to the plate and take care of your problem directly.
What I've seen happen before is that the customer will call Honda Customer Service (these people are NOT technicians). They will gather info and usually have the Honda Marine Service manager contact the dealer to make sure the customer is being well cared for and the problem corrected.
I've said it before, find a good local dealer and cultivate a relationship with them. Glad this issue turned out to be "manini" (small, inconsequential). Maybe see some of you in a couple weeks on the west side of Prince of Wales Island- look for......Hunky Dory! Aloha, Steve
 
Steve, thanks so much! That's the same bulletin that the local dealer was referring to. I haven't noticed the engine "making" any oil, so I don't think I have a problem with oil contamination. I'll certainly keep an eye out for it.

One of the frustrating parts here is that the Honda dealer didn't really make much of an effort to get the part here quickly. He called the Honda dealer in Juneau to see if they had it in stock (they didn't), but he did not even bother to check with Honda Marine to see when the part could arrive if he ordered it. Something about having to wait on the phone for hours on hold. So I just figured it out myself.

Again, thank you for the clarification!
 
On the phone for hours on hold? Never happened to me. If I need a Honda part quickly, 2 minutes on the computer and I know for sure it's on its way to me as quickly as I choose. Different business styles, I guess. I can't dis the AK dealer, though. This is the height of their short, busy season. I hope they're able to stay on top of things, and get some fishing in themselves! Again, glad it was a minor issue. Thanks for the continuing updates. Be safe and adventurous. Aloha, Steve.
 
Hello All,

I have a 2007 Honda BF90D 90 EFI and have checked since day one for any
recalls or service bulletins and only (1) recall is mentioned and I have not seen
any service bulletins on this particular model. There are recalls and service
bulletins listed for other models but not for the "new: 90 EFI. The dealers I've
contacted in this part of the country are clueless.

I went ahead and ordered new parts just to be on the safe side and have
spares in case this issue rears it's ugly head.

Thermostat Cover 19300-ZY9-000 (Hopefully It's Aluminum)
Thermostat Assy 19315-ZW9-003
Thermostat Cover O-Ring 19317-ZW9-000

Regarding the fuel dilution problem:

I have often wondered if that was happening because every time I have
changed the oil (which is quite frequent compared to the recommended
schedule) I always have noticed a strong odor to the oil compared to
every other engine I have ever owned.
By the way I have not observed any increase in the oil level on the dipstick.
I assumed that with fuel injection there would be relatively precise metering
of fuel to each cylinder compared to a carburator. In addition, I assumed
that because the BF90D EFI engine is certified "low emission" it would run relatively lean. Fuel dilution is not good for the bearings and reduces the
lubricity of the oil among other things.
Fuel dilution works good in aviation (DC3s) for reducing the viscosity of straight weight oil in order to start a radial engine in frigid temperatures but not in new Honda 90 EFIs. I question Honda's Programable Fuel Injection algorithm.
I don't think that anyone has been able to get a straight answer from Honda.
If anyone can figure out how to get service bulletins from Honda Marine,
please let me know.

By the way, I have had Zero issues with this engine.

Well I've rambled on long enough.

Mike
CD22 "Allyson Marie"
 
Well, let me see if I can dip my oar in the waters here (and not splash anyone).

As has been mentioned several times Honda Marine has not issued a specific bulletin regarding replacement of the thermostat cover. The only place that reference to this exists is one short mention within Step #36 on Page 12 in Bulletin #73 (revised May 2012), which is a 16 page document, indicating the cover can get distorted from corrosion, and if it is distorted they suggest replacing it with the newer aluminum cover.

The lead in to the above information reads: "Earlier engines have a plastic thermostat cover" implying that engines built after the "earlier engines" already have aluminum covers. Which likely means the vast majority of engines do have the aluminum cover already since the bulletin was from just a couple of months ago.

The other thing to note is that the thermostat cover has NO bearing on the problem (Oil Dilution) being addressed in Bulletin #73. That is, the recommendation to change to the aluminum thermostat cover has nothing to do with oil dilution, it's only mentioned in the bulletin because the thermostat is being replaced as part of the actions called for in the bulletin. Said yet another way, a leaking thermostat cover is not the cause or a contributor to oil dilution.

The risk that a leaking thermostat cover represents is saltwater dribbling down the side of the engine. And while this is not something that should happen it is not a safety hazard and therefore is not a "Recall" item which has very specific legal requirements and procedures.

The problem with Service Bulletins or Product Updates and publishing them for any company is that some level of understanding of the underlying problem is necessary to evaluate what should or must be done.

For instance, let's say 1% of the Honda BF90D engines has a plastic thermostat cover that has become deformed and leaks (we know it's not all of them or there would be a Product Update from Honda, not just a mention in a service bulletin for another situation). If Honda (in this case but it would be the same for any manufacturer) issues and publishes a Service Bulletin regarding the potentially leaking thermostat cover then 99% of all owners who get the bulletin will needlessly worry about whether or not their engine is involved. Some of them may even needlessly spend time and money to haul their boat to a dealer only to find out it's not an issue. [You may argue my percentage assumptions but even if you make it 5% of engines that still leaves 95% without issues. It can't be anywhere near 25% because by then there would be a Product Update.]

There is no doubt that many C-Brats could check the engine and ascertain whether or not their engine has a plastic thermostat cover and then some (likely smaller number) may also be able to ascertain whether or not it's leaking. But the vast majority of BF90D owners wouldn't know where to look to find out or even have the desire to do so. C-Brats represent a small subset of owners and by their very nature are the more technically minded and/or proactive.

Also, the vast majority of outboards in the U.S. are not used in saltwater environments; freshwater boats far outnumber coastal boats. If the cause of leaking of the plastic thermostat cover is corrosion (due to saltwater) that means that, percentage-wise, very few BF90D engines are subject to the potential problem.

I understand the emotional argument that everything should be disclosed and information presented to owners. I also understand the practical implications of doing that. If I had to make a decision like that I sure wouldn't want to have thousands of owners spend the time and money to haul their boat to their local dealer only to find out they don't have a problem. That's tens of thousands of dollars potentially wasted not to mention the countless hours spent at the dealership level.

Outboard manufacturer's are subject to the same legal requirements as auto manufacturers with regard to recall issues. If there's a documented safety issue involved a Recall will be issued and every owner of record will get a notification.

In this particular case would it have been better for Sam to have known about the issue? Yes, of course, he's got one of the few BF90D engines out there that's experiencing a leaking thermostat cover. Was it an inconvenience? Yes, of course. Was it a safety issue? No. Had he never know about it he would have been able to finish his trip without trouble. Everything in that area, and the ECU most of all, is waterproof (makes sense for an outboard) and he has a better chance of winning the Power Ball lotto than developing issues due to the thermostat cover leaking. Of course it's different once you know about it, then you want it fixed so you don't have to worry.

We check the serial number of every Honda we service in the Honda Dealer database and I'm sure many other dealers do as well. What we get from that is sale date, warranty expiration date, and any outstanding Product Updates or Safety Recalls, there is no specific bulletin regarding the replacement of the thermostat cover. The database won't turn up a three sentence recommendation in a Service Bulletin related to Oil Dilution, so unless someone at the dealership is personally familiar with the information it isn't something that can be passed along to the customer. In this case someone would have had to remember a small bit of info buried in a 16-page document, which would typically only happen if you had engines showing up with the issue the Service Bulletin addressed (in the case, oil dilution). You might also know about it if a mechanic had previously seen it on an engine being worked on but that's pretty circumstantial.

I believe in this case, since Retriever was here, we may have been one of the dealerships that didn't tell Sam about the thermostat cover. We simply weren't aware of the problem because we haven't had any BF90Ds here with oil dilution issues (and that Service Bulletin is where the thermostat cover information is).

If Honda has chosen not to address the issue in a specific bulletin then it isn't a widespread problem (of course it's an "in your face" issue for Sam and I totally "get that"). Honda is not shy about taking care of customers and having dealers keep the engines running in top shape. Honda relies on their reputation for reliability more than just about anything else. In the 15+ years I've worked with them I've never had them deny a claim or even argue one. I have had them pay for work on engines far out of warranty but which they deemed shouldn't have happened anyway. They're not perfect but they go further than any other manufacturer we've dealt with.

Ye Gads! A wall of text! I should have thrown some photos in there I guess.

Les
 
Les, I really appreciate you taking the time to respond to this and I spoke with Kathy yesterday and she was very helpful as well. I've now talked to Honda Marine (corporate) and three Honda dealers and gotten somewhat different info from each, which can be frustrating.

The local dealer here in Sitka said this is a common problem in his experience. Actually the only common problem on these engines, they're just about bulletproof otherwise. He was very concerned about the water on the ECU (and told me not to use the boat until it was fixed), hence my concern about the issue. It's good to know that it's not something I should worry about.

If this were to happen in the Seattle are it would be no big deal. The only challenge was getting the part up to Alaska, which ended up working out beautifully. One of the joys of cruising is problem solving!

I do still wish Honda had told me that there may be a problem with the tstat cover. I would have gladly paid the $20 for the more robust aluminum part in order to not have to deal with it. Oh well, live and learn.

The good news is the remedy is inexpensive and easy. Based on my experience, owners of BF90D's operated in saltwater should go ahead and swap out the tstat cover as preventative maintenance.

Thanks again for all the help!
 
Les, thanks for covering this issue better and more completely than my late-night attempt. I agree with every word. Oh, and Mike, both the part #'s for the tstat and cover that you listed are invalid #'s....All Bf90d owners need to understand that their engine has 2 thermostats, one for cyl head, one for cyl block temp control. Different tstats, different covers. Aloha, Steve.
 
Steve,

Thanks for the heads up on the part numbers. I transposed the numbers,
but as I understand it the correct number of the aluminum thermostat cover
is 19315-ZY9-000. If it is not then what is it? I was told that the correct
thermostat for the Block (60 degree) was 193-ZW9-003. So now what?
I 've checked my BF90D shop manual, Internet, and talked to Honda parts
guys. I got my 90 EFI in Feb of 2007 and believe me the first few months that
I had it hardly anyone, especially in this part of the country even knew much
about it. ( It drove the parts guys crazy)
I couldn't find spare plugs, fuel filters or much of anything for this engine.
Helm didn't even have the Honda Factory BF90D shop manual listed yet.

I realize that the 90 EFI has (2) thermostats. (Since day one)

All in all it's been a good engine. It starts instantly after sitting all winter and
runs really well.

Separate Issue:
The only concern that I have is that the oil gets really dirty really quick and
has a strong odor (A noticeable fuel smell) which leads me to believe that
fuel diliution may be an issue. (Not a big issue)
I've always used Honda Marine 10W30 Oil for those that may have thought
that I use el cheapo oil.

Please don't flame me guys, but that only reason that this Original post caught
my eye is that as a mechanical engineer for 3O+ yrs at hp I know what can
happen when supposedly sealed electrical components, cables and sealed connectors get around salt water, bad things can and do happen.

Could someone out there please let those of us that have Honda 90 EFI
engines know what the correct part numbers are for aluminum thermostat
cover, O-Ring for the cover and both Thermostats for spares.

Thanks,
Mike
 
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