208 Adventure Top end

[seasick]

Yep, I'm in agreement with Doc. 4000 RPM WOT is way too low and is about the top end drop I'd expect with a cylinder not firing... Could be something simple like a bad spark plug or loose spark plug wire.

FWIW, I have a different motor, but many years ago I had just had the motor serviced which included new spark plugs. With less than 10 hours on the plugs, we were cruising along and the motor all of a sudden lost power and we couldn't get more than 4200 RPM at WOT (normally it is 5300). Back at the dock, the first thing we did was put the old spark plugs back in which solved the problem. So whether it was a bad plug or a wire wasn't popped onto a plug properly at the shop, I will never know. I just bought another set of plugs and swapped them out since I didn't want to waste the time trying to figure out which plug was bad, if any.

I bet the plugs weren't iridiums Chucking new $3 plugs is not nearly as painful as chucking $15 or more plugs..

 

[enfish]

I bet the plugs weren't iridiums Chucking new $3 plugs is not nearly as painful as chucking $15 or more plugs..

Haha... For sure. At the time we were staying at a dock that was a 45 minute, 5 mph harbor cruise to the open ocean. Neither the thought of a 1.5 hour round trip to and from the dock, potentially up to 6 times, to try to determine the bad plug, or trying to change a spark plug out in the open ocean was appealing, so I probably would have paid the $15 each... either that or just left the old ones in for another 100 hours...

 

[luckydude]

I will mention, though, that if you had the engine trim all the way down AND you had the tabs all the way down AND you feathered the throttle to full (or close) there should have been VERY little bow rise. You should have absolutely zero issues getting on plane. Really, with a light load, you shouldn't even need the tabs.

I've got the 208's bigger brother, 228 with 2 feet more deck, 250, and swim platform. Other than that, identical boats. The 208 is probably close to 1000 pounds lighter with a full gas tank.

I get on plane just fine with that 250, the only time it struggles a little is in really lumpy water. I have _never_ needed to use the trim tabs to get on plane, single engine Gradys shouldn't need that, double/triple engine boats are a different kettle of fish.

 

[jason808]

Put it in the water for a quick run to get the trailer weighed so I can register it.
Winds were blowing 25-30knts, and was pretty choppy in the bay.
It felt a little better today, but really struggles to get on plane.
Got it a little past 30mph but was too rough to really get a feel.
This time i started with much less trim.
Here are some pictures of the engine at about 30 mph.
My wife was driving and I luckily did not lose my phone

As far as mechanics go, it is hard to find a good one with availability out here.
Will check the plugs this weekend.

 

[DennisG01]

This time i started with much less trim.

Wait, something isn't making sense. Earlier, you mentioned you started with full down trim. Now you started with much less trim. How can you have "less" than full down?

Plugs.

 

[seasick]

Assuming the motor can be tilted 'down' more than parallel to the transom, that angle can be referred to as negative trim. What the trim gauge reads depends on how it was calibrated/set up. On my Yamis you can't display less than zero bars but the zero bars could actually represent an angle less than 0 actual degrees.
On my Merc gauges, the trim can be calibrated to represent the real angle. In that case, I can trim past 0 degrees to a negative angle if I set it up that way.
On my 208 fully trimmed down is actually a negative angle and that will push the bow down more than 'straight' down. Regardless, I don't think trim is the OPs problem. The setup appears to be down on thrust.

 

[jason808]

Wait, something isn't making sense. Earlier, you mentioned you started with full down trim. Now you started with much less trim. How can you have "less" than full down?

Plugs.

I understand, it is helpful to be more precise with my words.
The first time I put it in the water I started off with full down trim, and gradually trimmed up. I was also using the trim tabs. In addition I put the throttle all the way down, and it seemed stuck at 30mph and 4000RPMs.

When I put it in the water yesterday, my second time, I did not have it at full down trim, it was trimmed further up then what I had the first time. I can take pictures of the display next time. It performed a little different, and seemed to have a a little bit more power but still struggled to get on plane.

It seemed power was an issue. My original intent of the post was
1] to see what was normal for other people driving the same boat/engine or close enough
2] to see whether it was something as simple as I need to use the trim and trim tabs in a different way then I am used too
3] whether I need a different prop, I came from the east coast and spent most my time there boating from mostly in the Chesapeake, but also trailered from Hatteras to Montauk. The waters over there are different then Hawaii waters.
4] whether there was an actual mechanical issue with the engine

I think 4] is unlikely. The boat is only a year old but was sitting for a bit without being used. The broker I purchased it from, did the 20 hour service before they shipped it over and the engine had no faults. When I drove it this weekend, it was probably the first time someone took it past neutral in aboat 6 months.

I can't thank you all enough for the input. I will check out the spark plugs.
I have to wait for the winds to die down, to run it and do further testing.

 

[coldpizza]

I had a 1993 200hp 2-stroke and repowered to a 200hp ETEC in 2010. I would see 42 mph on both motors (ETEC a little faster). I think it was 15x16 prop. I had to do a little trial and error to find the right prop. I sold the boat a few years so I can't confirm the prop. It should easily hit the high 30's low 40's if the seas will allow.

 

[ScottyCee]

Yes - whole bunch of reasons this cold be happening. Common is VST filter needs a cleaning, but there is also the shift switch under the cowl that will start to short cylinders if it is malfunctioning. You will need to do some detective work. If you had YDS it might tell you right off the bat, but no guarantees...

 

[DennisG01]

OK, thank you for the clarification. No, need to take pics of the trim gauge. Just for clarification, I'm summing up "proper" trim use (forget about the tabs for now as your boat should do fine without them). You may know all this, but just in case...

-- Always start with full down trim.
-- Apply throttle smoothly and to at least halfway (depending on load). It's not a problem to apply full throttle.
-- The bow will rise up a bit in front of you and then start to come back down and level off. You are now "on plane".
-- At this point you can raise the trim to keep the bow from burying too far in the water. With practice you can start to trim up as the bow is starting to come back down, if you want.
-- You can also pull back on the throttle as the bow comes back down.

OK, that said, let's get back into this. Now, there can actually be some boat-side issues here and/or some engine-side issues. Let's try to eliminate one of those sides to help narrow things down.

-- Beg, borrow or steal a portable 6-gallon fuel tank. Disconnect the hose that's on the engine side of the fuel/water separator that's mounted on the boat. Connect the portable tank to this hose with a simple barb connection. Go run the boat.

-- If the issue is still present, the problem is either the hose going to the engine (unlikely) or something at the engine, itself. If you want, you could connect the portable tank's hose directly to the F/W separator that's mounted on the side of the engine.

-- If the issue goes away, the problem is the F/W sep, the line to the tank, the tank pickup or the vent system.

If you can narrow this down for us, it will help. Reading the plugs will help, too.

??? Given it's a newer boat, you probably have an EPA carbon canister in the vent system. If so, this "could" be the problem as it may have gotten saturated. This would effectively create a problem like putting your finger over a straw, stopping full fuel flow. The same would happen with a clog anywhere in the vent system. Two quick tests... when the engine is struggling, you may find that the fuel bulb is flattening. That is a dead giveaway that there's a clog in the vent system (or internal line failure... although that's unlikely given it's almost new). Another way to find out if the vent system is to blame is to run with the fuel cap off - which creates a new "vent", in essence.

I know I wrote a lot here, but I'm trying to come up with ideas that could explain your problem and are relatively easy to check and at no/minimal cost to you before spending money on engine-related things.

 

[seasick]

I understand, it is helpful to be more precise with my words.
The first time I put it in the water I started off with full down trim, and gradually trimmed up. I was also using the trim tabs. In addition I put the throttle all the way down, and it seemed stuck at 30mph and 4000RPMs.

When I put it in the water yesterday, my second time, I did not have it at full down trim, it was trimmed further up then what I had the first time. I can take pictures of the display next time. It performed a little different, and seemed to have a a little bit more power but still struggled to get on plane.

It seemed power was an issue. My original intent of the post was
1] to see what was normal for other people driving the same boat/engine or close enough
2] to see whether it was something as simple as I need to use the trim and trim tabs in a different way then I am used too
3] whether I need a different prop, I came from the east coast and spent most my time there boating from mostly in the Chesapeake, but also trailered from Hatteras to Montauk. The waters over there are different then Hawaii waters.
4] whether there was an actual mechanical issue with the engine

I think 4] is unlikely. The boat is only a year old but was sitting for a bit without being used. The broker I purchased it from, did the 20 hour service before they shipped it over and the engine had no faults. When I drove it this weekend, it was probably the first time someone took it past neutral in aboat 6 months.

I can't thank you all enough for the input. I will check out the spark plugs.
I have to wait for the winds to die down, to run it and do further testing.

I think it is #4.

 

[enfish]

I understand, it is helpful to be more precise with my words.
The first time I put it in the water I started off with full down trim, and gradually trimmed up. I was also using the trim tabs. In addition I put the throttle all the way down, and it seemed stuck at 30mph and 4000RPMs.

When I put it in the water yesterday, my second time, I did not have it at full down trim, it was trimmed further up then what I had the first time. I can take pictures of the display next time. It performed a little different, and seemed to have a a little bit more power but still struggled to get on plane.

It seemed power was an issue. My original intent of the post was
1] to see what was normal for other people driving the same boat/engine or close enough
2] to see whether it was something as simple as I need to use the trim and trim tabs in a different way then I am used too
3] whether I need a different prop, I came from the east coast and spent most my time there boating from mostly in the Chesapeake, but also trailered from Hatteras to Montauk. The waters over there are different then Hawaii waters.
4] whether there was an actual mechanical issue with the engine

I think 4] is unlikely. The boat is only a year old but was sitting for a bit without being used. The broker I purchased it from, did the 20 hour service before they shipped it over and the engine had no faults. When I drove it this weekend, it was probably the first time someone took it past neutral in aboat 6 months.

I can't thank you all enough for the input. I will check out the spark plugs.
I have to wait for the winds to die down, to run it and do further testing.

I also think it's number 4...

1. What you're experiencing is not normal
2. There's no way an improper trim would put such a load on the motor that you'd drop ~1500 RPM from your rated max.
3. You're not over-propped with a 14.25x17 prop on that motor with that hull
4. The only thing left is something mechanically wrong with the motor.

You're in Hawaii, right? and your boat was shipped from the mainland? It's possible something was disconnected for the shipment and not reconnected properly...

 

[luckydude]

Listen to seasick. Not that you are not but he's been around the block. Lots of good advice, no disrespect to the others, but start with him.
I got on here and asked for advice and didn't dig into who was telling me what. Tons of good advice, tons of nice people trying to help. I can list off the people that I listened to, there are a bunch and seasick is up there. Most of the people on here will give you good advice but seasick has been here for a long time.

For magicbill and the rest of you who have guided me, no disrespect, just trying to nudge a new guy.

 

[jason808]

First thing to check is that the throttle linkage on the motor is moving all the way to open throttle when the lever is pushed forward. Do that with the motor not running.
4000 revs WOT is way too low for that motor.
Many possible causes but some more common than others. Assuming the motor isn't surging when it maxes out, the issue is probably not fuel flow. It could be a wrong prop or loss of spark. You can test spark with an inexpensive tester from harbor freight. Note that some motors turn off certain cylinders at lower revs so check spark one by one at the dock if possible with boat tied off and in gear .Check for spark at about 2,000 revs.

I am not sure of the LU gear ration off hand. I need to check but regardless it should be revving higher. How did you determine the pitch? The number stamped on the outside of the hub may not be the specs , especially if it is a single number like 17M.

If you start from a stop and jam the throttle way forward, do the revs increase uniformly or do that increase rapidly without a corresponding increase in speed?

Did the boat ever make more than 4000 revs at WOT as far as you know by experience.

Here are the engine records, from before I used it. I ordered a service manual, will check out the throttle cable, spark plugs, fuel flow, and plan to take it for a run somewhere on island with nicer water.
I appreciate all the guidance on areas to look for. The good yamaha techs out here are super busy, we are in the midst of ahi season, and they would definitely appreciate if I went to them with a more detailed description of the problem.

Beers on me, if any of you all make it out here

 

[seasick]

The second printout shows that the motor never made WOT revs. It has a small amount of time in the 4 to 5000 range but that could have been 4001
I am hoping it is something simple like a loose plug wire but I am also concerned that the problem may have existed from birth. I think you should seek professional help.

 

[seasick]

Luckydude,
Thanks for the endorsement but I am not an expert by any means. Since I have had a 208 for 15 years and do all my own work ( that's getting harder these days) including the work on the SX motor, I do have a decent knowledge of that package. I will also admit that I am often wrong in my suggestions and usually due to assuming info without fully researching it.
If you follow the forum frequently, you may have seen that I have been known to respond to a post and 5 minutes later delete that post after I realize what a dope was.
Believe me, there are members on this forum who have more knowledge about boating than I will ever have.

 

[Doc Stressor]

Your record shows that the engine turned 5429 rpm at 3.8 hr during the break-in period. That was on the boat, not with a test prop. So something must have happened since then to screw up your performance. You indicated that the seller performed the 20 hr service just before shipping the boat to you. It's not uncommon (but a bad practice) for a confident (not the same as competent) mechanic to skip the in-water test run.

Check the plugs and wires. I would not be surprised if they left something loose.

 

[seasick]

Doc, how does the second screen shot relate to the first? The second shows no hours in the 5000+ range

 

[Doc Stressor]

The system won't log a time at rpm range unless the engine was run for at least 0.1 hr.

The 5429 rpm at 3.8 hr was likely just a full-throttle burst for a minute or so. It would take 6 minutes (0.1 hr) at over 5000 rpm to register on the data logger.

 

[seasick]

ok, so basically we can't tell if that motor ever made proper revs near WOT under load in the water.