F90 Broke Again, I give Up

[99yam40]

Is this one of the issues that Rod mentioned will cause the motor to lock rpm to 2000? Can't recall

I believe the IAC valve opens to 100% during shut down getting ready for the next start.
if the connector looses connection then it cannot close off to slow down the idle speed.

I do not think it would affect high RPM running just the idle, but I am not someone that knows for sure.

not sure how easy it would be to fool that motor to start up in gear. You would need to jump the starter circuit, but the ECU would know it started in gear and may cause some alarm and some other things to happen.
Maybe no big deal if just a code or alarm.

The OP may just need to pay better attention when pulling and installing the cowling to solve the problems he has been having, and make sure the wiring is secured better so it will no hang up when jacking with the cowling.

After all it ran well for many years since he bought it 10 years ago.

OP should have showed up here back when these problems showed up and maybe we could have helped him not get a repeat of the problem before he gave up on the yanaha

Just have to wait on his report back what they find

[Jason2tpa]

This is all a bit shocking that by removing the upper cowling could cause this issue. Hard to believe the engine would leave the production line with even the slightest probability of the cowling snagging. However, this issue is believable if electrical sensors/connections/components are not in their original place.

[pstephens46]

Known issue on some of these motors. Been posted about before.

[FLCoyote]

F90 Broke Again Update

As I stated previously I took my Boat/F90 to a certified Yamaha dealer other than the one I have been using. His take so far is that the Wiring Harness has not been the problem and that the wiring harness and visible repair weren't necessary. He diagnosed it as a sticking Idle Adjustment Valve ($258) and thinks that in process of working on/replacing the wiring harness by my regular dealer the IAV was unstuck and stuck again when conditions were right. The new valve isn't in yet so we will see. The mechanic I'm working with is an instructor in marine repair and has about 30 years of experience. Regardless, the list of problems I've had with this motor include: Replacing two ignition switches, one voltage regulator, Non-ethanol resistant fuel lines disintegrated resulting in new fuel lines, new filters including the VST and drain and clean the tank, Tilt and trim relay went bad (replaced myself), tilt and trim motor went out, paid for one rebuild lasted six months then new tilt and trim motor. One new wiring harness plus two wiring harness repairs, and a lower unit rebuild. One of the previous comments was that I had apparently had good service for a number of years from this motor and while I can see how that may seem to be the case, from my perspective its been chronic problems from day one. One of my previous boats had a two stroke 85HP Force on it which lots of people assured me was a piece of junk and only good for an anchor. I had that motor for 11 years with one repair for a bad stator and the motor had a lot of hours on it. I maintain that my F90 had regular maintenance and no abuse. I did run it offshore in rough conditions a lot and occasionally took one over the stern, but don't know why that would contribute to all of these issues. The above list isn't comprehensive just what I can remember offhand and since I'm a Senior Citizen with CRS I tend to have a pretty poor memory. Anyway the new valve should be in today and maybe I'll get to water test the boat this weekend. Will post results of Water test. FLCoyote

[FLCoyote]

F90 Broke Again, Update

Picked my boat up yesterday afternoon. Repair was $469 and included a new Idle Adjustment Control Valve. Mechanic said that after I took the boat in for repair that it started one time, then shut off and wouldn't restart. He got it started again by hooking it up to the diagnostic computer and con*****ing the idle adjustment with the computer. His take again was that the Wiring Harness has not been the problem. If that's true it cost me around $2400 total and five total haul in's for repair including this one and the $2400 is not inclusive of this repair. My mechanic did say that the Wiring Harness problem is caused by owners lifting the Cowling slightly and pulling it off by tilting it back while standing behind the motor instead of lifting it completely clear vertically. Since I always do lift it vertically I tend to agree with him that the IAC has been the problem from the start of this issue. I think I was lucky that when the motor started acting up offshore that I got it started and in gear and ran back in right away. I haven't water tested the boat yet and still think I'm going to sell it, probably in Mar/April. Don't know if I should tell buyer about all of the trouble I've had with this motor or offer to let him have it checked out at their expense or not. As far as I know its in good shape after all that I've had done. I've added Hydraulic Steering, a Tee Top with Electronics box, and will include my Humminbird Side Imaging Depthfinder, with 451 local offshore and in the bay spots already marked? After doing a lot of research, including on this forum, I've concluded that Yamaha has done a very poor job with resolving problems with the F90, and F150 IAC Valve. The F115 seems to have escaped this problem. Thanks to all who commented. Just like a blind squirrel finds an acorn every now and then, I think that every once in a while someone just gets the proverbial lemon in a boat motor. Too many boat owners swear by Yamaha motors while I just swear at mine. FLCoyote

[cpostis]

Well, looking at your post history, seems to me that maybe if you replaced that ICV (IAC) back in 2012 when you first had the problem (diagnosed by mechanic as "two broken wires", and since had problems with high idle), you may have avoided many expenses (rebuilt l/u, wiring harness [not needed per your mechanic], haul ins, etc,). Your expenses for "Non-ethanol resistant fuel lines disintegrated resulting in new fuel lines, new filters including the VST and drain and clean the tank, ect.", you cannot blame on the motor. I just this tear replaced my 2001 ignition switch because of the key being sloppy in the cylinder and the alarm being lower volume than I thought should be, strange you should have to replace three. Just how weather resistant is your electrical in your console?

My point is not to blame you, but I think some things could have been done better in dealing with your problems. I find I do not "swear at my Yamaha", I praise it.

One more thing, I frequently motor out 25-30 miles offshore and I have tow insurance that I pay about $120 a year for. Used it once back in 1990 when I was a mile off shore powered by an Evinrude (took a wave over the bow that flooded/shorted my center console electric, not motor problem). Well worth the expense.

[FLCoyote]

Response to Cpostic

Cpostic,

I agree that I could have handled some of the various issues better, however the wiring harness issues and replacement and repairs have resulted in most of my frustration. Here's the back story. The boat was rigged in Atlanta by a boat dealer that was a friend of the original owner. I don't think the person that rigged it had any idea about a salt water environment and was thinking Lake Lanier when doing the rigging. I've also had a lot of other wiring and trailer problems caused by corrosion that could have been prevented if rigged for salt water. The original owner had marital problems right after purchasing the boat and sold it to me 89 days after the bought it. He hadn't drilled a hole in it or added any accessories and said he had only used it twice. I wash my boat and tackle down thoroughly after each use and still had problems like the trailer axle rusted out in about 18 months, replaced the trailer wheels within three years and finally the iron U-bolts used on the aluminum trailer ate into the trailer cross-beams which cost me about $500. The trailer repair shop said they couldn't imagine not using stainless U-Bolts on an aluminum trailer. The fuel line problem is not unusual for non-ethanol resistant fuel lines which weren't mandatory until 2006. I think the voltage regulator and ignition switch problems were caused by poor rigging. The tilt and trim problems were probably just normal wear and tear. This is my third boat in 30 years and absolutely the worst in terms of problems and expense. I can't think how I could have handled things differently as I just took it as it came. The only repair that was under warranty was the voltage regulator/alternator. Throw in the Fuel line/gas problem with the supposed Wiring Harness fiasco and I'm just frustrated with constant repairs and expense. I appreciate your comments and the comments of everyone that posted. I talked to a fishing buddy who has a F115 during the time I had the F90, and he never had any problems other than normal routine maintenance. I probably am tempting fate by saying this, but I've had a 2001 Toyota Tacoma TRD/4WD since 2001, without a single problem and I have always been meticulous about maintaining my firearms, fishing equipment, vehicles, etc. In this case I just seem to be cursed. I've still got to water test this last repair and then decide if I'm going to put the boat on the market. I kind of hate to stick someone with it, but wouldn't sell it other than "as it".

[tarheel53]

Coyote,

Feel your pain. I own an old Whaler that I repowered with an F150 in 2004 - it's been bulletproof. My buddy repowered his smaller Whaler with an F90 about the same time - endless problems.
During this same time period we both owned Chevy Tahoes bought new :
mine needed new trans, 2 radiators, heads and finally unloaded it when I was told it had a cracked block. His ran 350K with only oil changes and brakes.
Sometimes you're just snake bit.

[FLCoyote]

F90, Old Story, Same issue

Had the IAC replaced about four months ago. Took wife and daughter on 30 mile trip around the bay about two months ago, no problems. Took prospective boat buyer on demo cruise about three weeks ago, no problems.
Went fishing last Saturday morning and got high idle problem again, noticed grinding when shifting to forward and reverse when loading the boat to go home. RPM's were at 1200 and wouldn't back off until I shut the engine off and restarted it. I had all known problems fixed and cleaned the boat up so I could sell it with a clear conscience, now I'm back to the high idle problem I've been plagued with for five or six years. It may be that dynamite is the only option. Seriously I'm planning to advertise it and tell a buyer if I find one about the problems and just give them a break on the price. I've been very careful putting the cowling on and off and like I said had it all fixed up about four months ago. Frustrated beyond rational thought. Just sharing my feelings. My wife says it makes her feel better so I'm giving it a try.
FLCoyote