Yamaha HPDI 200 low idle

[teaklejr]

I have a pair of 2007 Yamaha HPDI 200with about 800 hrs on each and when first started both idle low, 400-450 rpm and sometimes with cut out. Restart everytime and once warmed up they idle at 600 rpm and run perfect. When they are cold if you try and put them in neutral and bring the idle up the will cut off. This has been going on for about 3 years just never think about it when not at boat until today. All maintenance is kept up on. Just igured I would ask if anyone else has had this happen to them. Any info would be great

 

[reelserious]

I have a pair of 2007 Yamaha HPDI 200with about 800 hrs on each and when first started both idle low, 400-450 rpm and sometimes with cut out. Restart everytime and once warmed up they idle at 600 rpm and run perfect. When they are cold if you try and put them in neutral and bring the idle up the will cut off. This has been going on for about 3 years just never think about it when not at boat until today. All maintenance is kept up on. Just igured I would ask if anyone else has had this happen to them. Any info would be great

I have a pair of 2000 200 HPDIs with about 1,200 hours. Even if they sit for weeks they fire right up and go to idle. Given what you are describing, something is obviously not right. If nobody here can offer any insight, you might want to post on the Hull Truth......just don't tell them that the motors are hung on a Grady White.

 

[georgemjr]

Can’t explain the low idle whenyou first start, but 200 hpdis are designed to drop 2cylinders at idle. If you attempt to raise the idle in neutral, it drops 2 more. Have to be in gear to throttle up.

 

[seasick]

Assuming it ides at the right revs when warm, I would look for something related to temperature like the temp sensor ( or sensors) I don't know if that motor has one or two. The temp sensors may not be the same as the high temp limit switch that signals overheat as is the case with the SX models.
After checking those sensors, I would check the low pressure boost pump (s). To be honest, I have a similar issue with my 150 and have so for years. It is definitely more pronounced during colder weather. When the motor is cold and just started, I engage the shift override on the control and manually raise the idle to the correct speed and let the motor warm up

 

[BobP]

Are you saying BOTH motors idle low? And condition started at the same time?
There are no common Yamaha systems shared between motors. Except fuel. Is your fuel good? Can try hooking up a portable fuel tank with fresh fuel to one of the motors.

If it was one motor, there is a sequence of adjustments to perform per service manual to get idle right. Idle speed incl when cold is automatic don’t bother with the binnacle control. It’s turn key and go. Perhaps temp sensor if faulty. Not likely on both motors though. Aftermarket companies sell the firmware to connect a laptop to the engine. I used it worked well. As I recall one can check all the sensors, etc.

 

[Boxster964]

Have you ever replaced the tiny fuel screens/filters in the injectors or have you had the injectors cleaned?

 

[ROBERTH]

Hi teakljr, just now getting a chance to respond to this message. I have 2006 200's and have suffered the same issues. Very interesting what you have stated is exactly my symptoms as well.
Over time in last year or so, I have had them to a good mechanic and he had opportunity for over 2 months to try and resolve the issue. I spent the first day with him going over them, doing the sync and link, adjust the TPS, checking plug wires/boots, many other things and nothing seemed to help. I maintain my engines better than most and I know how to work on them for most of the parts.
The one thing he did finally find later was the O2 sensors were basically plugged up. This was at approx. 700 hours. He cleaned, serviced the O2 sensors and even had a Yamaha field rep following up with him. He then spent time following the wires and testing them throughout the entire wiring harness and no issues found.
Have had thermostats replaced, poppit valves, all filters except high pressure area. Nothing seemed to resolve the issue entirely. However, we did get them to improve some.
I have since taken it back and made some more adjustments and put another set of plugs in and got some improvement. One motor is pretty good now and the other still struggles. Once warm, they are ok.
Also, I adjusted the idle speed to 700rpm which is the manual recommendation and feel they run better at idle there.

I also want to note, I run Startron and Ring Free Plus on every tank fill. Also, he and I both feel that since I can get 5800rpms out of the engines wide open, there should not be any issue with fuel injectors or the filter screens there as it is not starving for fuel.

I am now at 1000 hours and overall, I am just dealing with it. When we back the boat in the water, before launching, I will startup the engines and get them in gear and throttle up slightly enough to let them warm up a bit. Maybe a minute and then once pull back to idle, they hold their own for the rest of the day.

One other last point is I had notices after all the adjustments, the oil burn was higher and smoking was more during cold start. I have made adjustments to the oil pump per the manual and also with some guidance from Andy from Sim Yamaha and the last 2 trips burned a lot less oil. I think that the excessive oil was causing excessive carbon buildup and thus why the O2 sensors were plugged up.

Over the winter, I will pull the O2 sensors and check them and if still heavy carbon, will decarb the motors and see how they do next season. Thinking that the oil burn is less and now I switched over to Amsoil on last 2 tanks, it will run much cleaner. Perhaps some of the issue here is carbon buildup. Not sure what else to check and Yamaha rep's have not been able to determine what is causing this specific issue.

 

[suzukidave]

not sure if it helps but i had a car that was starting at 500 rpm every time instead of the normal rpm because the ecu memory was being wiped every time i turned it off so it was starting in safe mode and remapping the fuel mix from scratch every time.

 

[seasick]

I am not sure if the O2 sensor was the culprit but it could be for a different reason. When fouled up, the motor will run rich. When cold, that is the same as 'choking'. A rich mixture when cold is normal. On the other hand, the O2 sensor also has a heater built into it. That heats up the sensor since it has to be warm (hot) to work correctly. Perhaps the heater is weak or not working well. I really could never figure out the issue on my motor. When I have the sputtering/stalling after a cold start, it only takes about 30 seconds with the throttle increased a bit for the problem to go away (the low idle issue). One other symptom is that my SX frequently runs a bit rough when first run after a cold start. The idle is not low but when I accelerate in gear, the motor shakes a bit and kind of sounds like it is misfiring. After about 10 seconds at speed, all is well and no further problems.
Note that my motor is 18 years old and a lot of things could be going on. It probably will remain a mystery for the rest of its life

 

[ROBERTH]

I have always attributed some of this to just how a 2 stroke has to wake up in the morning and clear it's throat! Oil settles and it has to burn it off as it warms up. Dunno. My old OMC Seadrive was the same way, but it was not computerized and controlled like the motors of today.

I just wish I had what I had when they were new. Turn the key and they were going on their own, no assistance was required. Seems to be somewhat of a choke control since the warmup seems to resolve the issue. Unfortunately, we can't adjust or tweek the choke like the old days.

I agree, it is not likely the O2 sensors, but they do control the fuel flow and that can also contribute to a heavier fuel load than normal which might require more cleanout. That is the carbon issue I think, but nonetheless, they are and should be services yearly and I had not ever done it before.
The O2 sensors were tested fully and not only by the mechanic, but also the field rep from my understanding. So recommendation was not to replace them.

I will for now, just live with it. Someday, would love to check out the new Mercury 4 strokes as they are intriguing in their new lower weight and design. Would consider the G2's but thinking would love to move away from the 2 stroke world due to these types of ongoing issues with the 2 strokes, even though I love how they run!

 

[seasick]

I think you are on to something. As I age, I also need some time in the morning to 'warm' up! So maybe the idle symptom are par for the course.

 

[teaklejr]

I think I will pull the O2 sensors this off season and clean them just see if that helps out. I too maintain both motors very well, new spin on filters every year, gear oil changed every year, spark plugs every year and low, high and vst filters every other year. Have always ran Amsoil 2 stroke oil and gear oil and use ring free with every fill up. Like you said both motors idle and run perfect after about 2 minutes. Since they perform normal after warm up I just assume it’s not a real problem and will just deal with it.

Hi teakljr, just now getting a chance to respond to this message. I have 2006 200's and have suffered the same issues. Very interesting what you have stated is exactly my symptoms as well.
Over time in last year or so, I have had them to a good mechanic and he had opportunity for over 2 months to try and resolve the issue. I spent the first day with him going over them, doing the sync and link, adjust the TPS, checking plug wires/boots, many other things and nothing seemed to help. I maintain my engines better than most and I know how to work on them for most of the parts.
The one thing he did finally find later was the O2 sensors were basically plugged up. This was at approx. 700 hours. He cleaned, serviced the O2 sensors and even had a Yamaha field rep following up with him. He then spent time following the wires and testing them throughout the entire wiring harness and no issues found.
Have had thermostats replaced, poppit valves, all filters except high pressure area. Nothing seemed to resolve the issue entirely. However, we did get them to improve some.
I have since taken it back and made some more adjustments and put another set of plugs in and got some improvement. One motor is pretty good now and the other still struggles. Once warm, they are ok.
Also, I adjusted the idle speed to 700rpm which is the manual recommendation and feel they run better at idle there.

I also want to note, I run Startron and Ring Free Plus on every tank fill. Also, he and I both feel that since I can get 5800rpms out of the engines wide open, there should not be any issue with fuel injectors or the filter screens there as it is not starving for fuel.

I am now at 1000 hours and overall, I am just dealing with it. When we back the boat in the water, before launching, I will startup the engines and get them in gear and throttle up slightly enough to let them warm up a bit. Maybe a minute and then once pull back to idle, they hold their own for the rest of the day.

One other last point is I had notices after all the adjustments, the oil burn was higher and smoking was more during cold start. I have made adjustments to the oil pump per the manual and also with some guidance from Andy from Sim Yamaha and the last 2 trips burned a lot less oil. I think that the excessive oil was causing excessive carbon buildup and thus why the O2 sensors were plugged up.

Over the winter, I will pull the O2 sensors and check them and if still heavy carbon, will decarb the motors and see how they do next season. Thinking that the oil burn is less and now I switched over to Amsoil on last 2 tanks, it will run much cleaner. Perhaps some of the issue here is carbon buildup. Not sure what else to check and Yamaha rep's have not been able to determine what is causing this specific issue.

 

[teaklejr]

Are you saying BOTH motors idle low? And condition started at the same time?
There are no common Yamaha systems shared between motors. Except fuel. Is your fuel good? Can try hooking up a portable fuel tank with fresh fuel to one of the motors.

If it was one motor, there is a sequence of adjustments to perform per service manual to get idle right. Idle speed incl when cold is automatic don’t bother with the binnacle control. It’s turn key and go. Perhaps temp sensor if faulty. Not likely on both motors though. Aftermarket companies sell the firmware to connect a laptop to the engine. I used it worked well. As I recall one can check all the sensors, etc.

Yes both motors do it and once warm run perfect. I think one did it a little before the other one, will idle about 400 rpm then when warmed up sit at 600 rpm with no problem. All fuel filters are always up to date with maintenance so I know it’s not a fuel issue.

 

[Punch53]

Can’t explain the low idle whenyou first start, but 200 hpdis are designed to drop 2cylinders at idle. If you attempt to raise the idle in neutral, it drops 2 more. Have to be in gear to throttle up.

George is correct. When my friend developed the stalling/rough cold idle problem we just popped it in gear until it warmed up a bit. The solution was easy. Changed the plugs.

 

[seasick]

Teajkejr wrote:
'Over the winter, I will pull the O2 sensors and check them and if still heavy carbon, will decarb the motors and see how they do next season. Thinking that the oil burn is less and now I switched over to Amsoil on last 2 tanks, it will run much cleaner. Perhaps some of the issue here is carbon buildup. Not sure what else to check and Yamaha rep's have not been able to determine what is causing this specific issue. '

If you are going to pull the O2 sensors, you might as well check them. That means that you check for continuity on the heater leads and voltage change on the sensor leads as the tip of the sensor is heated. Don't overdo the heating. I use a propane torch, not acetylene or MAP!

When I clean the sensor and I don't do that regularly, I suspend the tip in RingFree for a few hours. Do not completely submerge the sensor in cleaner.
Also inspect, clean and possibly change the thimble that is in the hole between the O2 housing and the cylinder itself. They can get gummed up. The design changed a while back, I don't remember when but the newer thimble looks more like a thread spool than just a metal cylinder.

 

[ROBERTH]

Here is a pic of the carbon buildup in the thimble when the mechanic pulled it.

 

[ROBERTH]

Hi folks, just an update. Over last post and over the summer season, the motors did perform better at cold idle. I did make some minor adjustments over the summer and as time went, they started the issue again at idle, but not as bad as before.

After my inspection last time for cleaning/servicing the o2 sensors, I was not happy with the amount of carbon in that chamber and the o2 sensor draw tube just totally full of loose carbon. I think the Amsoil did better than the Pennzoil as I just checked the carbon and it was not totally full, but it was still not right in my view.

So, this time, I went ahead and removed the intake cover and sprayed in the Seafoam Spray as instructed, let it hot soak and went through a couple of cycles of this. Wow, the smoke was intense. However, by the time the smoke was reduced, the motors both moved from the 700 rpm idle speed to 800 rpm's .They seemed a bit smoother as well.

I had ordered new o2 sensor draw tubes from Andy and pulled the o2 sensors. The draw tubes were a bit stuck in place and not easy to remove. Too much hard carbon, so to me, they are not working correctly if they can't float in the chamber. I spent time with the Seafoam and carefully cleaning/scraping all the carbon out of the bores until they were clean. Cleaned the o2 sensor and installed the new draw tubes and gaskets.

New spark plugs and now they start right up and act normal like they did when they were newer motors.. I am hoping that I had a real carbon issue and the draw tubes not working properly maybe throwing off the computer...dunno, just me guessing but so far, so good.

One would think that with the Ring Free Plus and Startron, it would help with the carbon buildup! I wonder what it would be like if I didn't use them at all?

I waited a week after this work and restarted cold, and both motors started like they were new again, idle went right to 700rpms.

I will hopefully get a clear weekend soon weather permitting and run to nearest lake to let them run a bit, but thinking the carbon buildup plus the o2 sensor draw tube chambers with hard carbon has been the root cause of the idle speed when cold issue.

 

[seasick]

Very interesting. The O2 thimble design was changes at some point but I don't know when the new design was standard Did your new tubes look like the old ones?
I have had the low idle when cold issue on my SX150 for years and I just got used to increasing the throttle in neutral when that happens. Once it wars up, the idle is fine. I am not sure it is O2 sensor related but your results might lead one to think so..

 

[Heckler]

Very interesting. The O2 thimble design was changes at some point but I don't know when the new design was standard Did your new tubes look like the old ones?
I have had the low idle when cold issue on my SX150 for years and I just got used to increasing the throttle in neutral when that happens. Once it wars up, the idle is fine. I am not sure it is O2 sensor related but your results might lead one to think so..

Yes both motors do it and once warm run perfect. I think one did it a little before the other one, will idle about 400 rpm then when warmed up sit at 600 rpm with no problem. All fuel filters are always up to date with maintenance so I know it’s not a fuel issue.

I suppose that the more motors that can be shown to behave the same can eliminate many possible causes -and perhaps point to new ones...so hear goes:

About 3 years ago my 2001 HPDi 200's also both started idling low at first start and more so when outside temp was cold. They would keep running at 400 -450 however and almost never stalled. When warm, (2 minutes?) they idled at 600 . They had about 1100 hours on them when they started this pattern of low idle. The fact that they ran and did not stall at this low speed, the optimist in me thought that all systems must running smoothly.

The motors behave normally at all other RPM's and I top out at 5500 RPM which on my 265 Express was the normal top end from "birth".

I have not spent much time nor have I had a mechanic focus on it as there was no operating inconvenience to me and no other performance issues developed since this started.

I will stay tuned to see if it is something I should all be more concerned about and to see if someone solves the puzzle on behalf of the rest of us.

 

[ROBERTH]

I have found over several forums over last few years, there seems to be a few of us plagued with this issue. You are right, it is not a deal breaker of an issue, but is something we know is not quite right.
With today's computerized motors, they should work properly and when they don't that means something is not quite right.

I am now wondering those that have this same issue, startup cold and run at 400 or so rpms, die a few times and keep restarting, ect, if it is for those of us that do long trolling hours or long idle/very slow speed type of engine time?
It makes sense to me that trolling for 7-8 hours in a day, even with the runs back at higher rpm's for 1.5 hours or so is not enough to clean out the excessive carbon built up due to the trolling....... Maybe that is the issue here all along.

Therefore, the hard baked on carbon in the o2 sensor chamber is not allowing the thimble or draw tube to work properly and provide the right air to the o2 sensor for it to make the right decision for the computer..

If this ends up being the solution, then I will decarb 2 times per year with the Seafoam and make sure I clean the o2 sensor chambers as well. At least I will test this theory in the upcoming season....I will maybe put about 50 hours on, then pull the o2 sensor and inspect/clean, etc. and see what it is doing.
Next few trips will be the determining factor if the carbon causing the thimble to stick was the cause for the low idle issue....