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Improving Your Mokai

Shop Talk => Mokai ES-Kape => Topic started by: Clark Babb on September 28, 2016, 01:45:39 PM

Title: directional control rod (from servo)
Post by: Clark Babb on September 28, 2016, 01:45:39 PM
Hi,
The directional control rod that is connected to the pump housing for control has worn down the ball on the end as well as the interior of the Quick disconnect. It will not retain and I have no control! Just purchased the Escape in January and have put about 80 hours on it. Any suggestions?
Title: Re: directional control rod (from servo)
Post by: Painlesstom on September 28, 2016, 04:12:25 PM
That's a flaw in the design, nothing you can do but replace the parts. You will have to contact Mokai and have them replace them under warranty. Looks like this is another problem for people to be on the look out for on these boats. The push rod is aluminum, and I could see sand getting in the socket and causing premature wear, would be a good idea to clean it out after ever trip and grease it then.

 Thanks for the info. Let us know how it works out.
Title: Re: directional control rod (from servo)
Post by: happul3 on September 28, 2016, 07:02:57 PM
Check if your servo constantly makes small moves back and forth (basically never stops hunting for center). This could be contributing factor to fast wear. If it does, it is easy to fix by opening the servo, reaching the micro-usb connector inside and reprogramming PID with OEM software. That's what I did first before going for ultimate solution in form of Tom's conversion to purely mechanical steering and throttle.
Title: Re: directional control rod (from servo)
Post by: Painlesstom on September 28, 2016, 08:48:31 PM
Check if your servo constantly makes small moves back and forth (basically never stops hunting for center). This could be contributing factor to fast wear. If it does, it is easy to fix by opening the servo, reaching the micro-usb connector inside and reprogramming PID with OEM software. That's what I did first before going for ultimate solution in form of Tom's conversion to purely mechanical steering and throttle.

While some people are comfortable with tinkering like that, I don't recommend the average owner to dig that deep trying fixing a system that is under warranty. Exception being they don't care about dealing with Mokai or the warranty and just want to try anyhow before ultimately gutting it all and going with my conversion. If somebody opens that servo and bombs the programming, Mokai would void the warranty and happily charge a hefty price to fix.  :-[
Title: Re: directional control rod (from servo)
Post by: happul3 on September 28, 2016, 09:48:22 PM
That's a good point about warranty, although it is just as easy to restore the original PID values as to change them. So one should just make sure to record values that are changed and restore originals if returning servo for warranty service.
Title: Re: directional control rod (from servo)
Post by: Painlesstom on September 28, 2016, 10:15:00 PM
They will know if you opened it up... Game over then. You are thinking everyone would think like we do, not the case though. lol We are comfortable with computers and nerd stuff like that. Most people would open a can or worms they couldn't close thinking they knew more than they did... hehe
Title: Re: directional control rod (from servo)
Post by: happul3 on September 28, 2016, 10:41:35 PM
Even if they can determine that servo was opened that should not void the warranty in absence of any evidence of modification.

But I do agree that unless someone is comfortable with electronics and has working knowledge of PID tweaking, this type of tinkering can be problematic.
Title: Re: directional control rod (from servo)
Post by: Painlesstom on September 28, 2016, 10:59:35 PM
Even if they can determine that servo was opened that should not void the warranty in absence of any evidence of modification.


They don't look at it like that.. Open the servo and it's gone.  :-X
Title: Re: directional control rod (from servo)
Post by: happul3 on September 29, 2016, 10:31:34 AM
If that's indeed their unwritten warranty policy, fighting it would seem too much hassle for too little gain.

But be that as it may, my main point is that if servo is constantly hunting (might happen only while moving, might happen only in a certain temperature range), replacing the connector parts would be only a temporary fix. The servo would need fixing too, whoever does that, Mokai or the owner.   
Title: Re: directional control rod (from servo)
Post by: Painlesstom on September 29, 2016, 11:29:33 AM
I don't think that small movement would be enough to begin wear to that extent. It would take lots of full deflection steering action to articulate that ball/cup union enough to cause wear patterns that extreme, he said it wore down to the point it won't even stay connected. That isn't going to happen without lots of movement, and a servo hunting for center isn't going to do that.
Title: Re: directional control rod (from servo)
Post by: happul3 on September 29, 2016, 01:03:45 PM
Let me describe what I observed and maybe you will not be so categorical. From the very beginning my servo made periodic noise with no joystick input at all. You can sense the slight movement of servo arm if you put you hand inside, but because of play in connection, the nozzle would not move appreciably. So aside from significant and pointless battery drain, this hunting was not a problem. However, on several occasions I noticed that servo hunts a lot more, again with no joystick input and on land. In those cases the nozzle would move very noticeably (I'd say 5-10 degrees, but it has been a long while). I could not figure out what makes this excessive hunting to appear and go away. I also have no idea if that happened less or more when boat was moving. If this does happen for the gentleman who started this thread, it seems plausible that, in combination with some sand inside connector, it would wear out connector a lot faster than normal operation.
Title: Re: directional control rod (from servo)
Post by: Painlesstom on September 29, 2016, 02:25:18 PM
I know exactly what you mean, and part of the reason I got rid of all that junk and replaced it with manual cables. I still don't believe that contributed to the problem though, not unless he left the power on all the time and it was hunting like that 24/7. He said he's put 80 hours on it, that is the tell tale that the wear was from lots and lots of use. Lots of vibration back there too, which could also contribute to the problem.
Title: Re: directional control rod (from servo)
Post by: happul3 on September 29, 2016, 03:43:25 PM
Yes, "sanding" induced by vibration is a very good point, which I was not taking into account. So even with the mechanical steering I'd better be greasing and checking for abrasives present and wear regularly.
Title: Re: directional control rod (from servo)
Post by: Painlesstom on September 29, 2016, 03:58:51 PM
I've noticed no wear on mine, the rod is stainless and the ball is brass. I dab a little grease on the end after every few trips and so far nothing has changed. I don't expect any problems, you will be fine if you do the same.  \./8
Title: Re: directional control rod (from servo)
Post by: mokamo on September 26, 2018, 07:41:25 AM
So if this joystick fails when you are miles away, can you still run the boat going back? Anyone had this experience and how did you go back? Is there a DIY to externally control the jet pump nozzle? Im sure the new upcoming 2018 model will continue to use the joystick design. I think i have no choice but to support the joystick as i prefer the 3 hull design for my own specific needs..But there must be a backup control in case it fails.. not the paddling nor trolling motor please..
Title: Re: directional control rod (from servo)
Post by: Painlesstom on September 26, 2018, 08:12:35 AM
If you go back and study my cable conversion, you will find everything is quick release and the boat continues to be utilized as the 3 piece design.... I plan to have a kit for the 2.0 too as soon as somebody brings one to me so I know what needs to be adapted. But if the joystick fails, you have no steering or throttle and would have to find a way to center the nozzle and then try to lean to steer (or maybe use a paddle) for the trip back as long as you have some string packed away somewhere so you can rig up some kind of throttle control. The ES-kape doesn't respond to leaning like the old models, left and right are opposite and you have to lean much harder to get a reaction.
Title: Re: directional control rod (from servo)
Post by: mokamo on September 26, 2018, 08:46:22 AM
Thanks Tom. I will definitely check your design.
I did not think about the possible throttle problem...
Title: Re: directional control rod (from servo)
Post by: happul3 on September 26, 2018, 03:27:51 PM
So if this joystick fails when you are miles away, can you still run the boat going back? Anyone had this experience and how did you go back? Is there a DIY to externally control the jet pump nozzle? Im sure the new upcoming 2018 model will continue to use the joystick design. I think i have no choice but to support the joystick as i prefer the 3 hull design for my own specific needs..But there must be a backup control in case it fails.. not the paddling nor trolling motor please..

Reminds me of my very first Mokai outing. The joystick did not fail, but the engine compartment overheated and (as I learned much later) melted plastic gear inside the steering servo. So the end result was the same, I lost directional control. I navigated part of the way back in the following manner: steer with paddle in the needed direction at idle or while engine is off, then gun the motor until boat veers of, repeat... Would've been easy on a lake. Unfortunately I was doing it on a fairly narrow tidal river, and of course against the tide :) I bought Tom's steering kit shortly thereafter - highly recommend anyone with Eskape to do the same.
Title: Re: directional control rod (from servo)
Post by: mokamo on September 26, 2018, 04:19:07 PM

Wow.
Mokai cannot just sell the same servo design in 2018 model without spelling it out how they fixed this known issue.
Bigger exhaust for overheating and better servo that can handle higher temp...
If they have no fix, maybe give buyers the option to either get their own steering design or Tom steering kit so buyers don't end up throwing their Joystick.  :) :)

Happul3,

What did you do to fix the overheating?
And thank you for sharing your experience..
Title: Re: directional control rod (from servo)
Post by: Painlesstom on September 26, 2018, 04:26:22 PM
The overheating is a multi point issue. First off many of the pulse port nipples that drive the fuel pump were improperly installed in the carb spacer, coming loose and causing a vacuum leak that resulted in the engine running lean which means more heat. Second, the air plenum is anemic which chokes off air flow for the cooling, then bridging it over to the carb intake makes the engine fight itself for air twice. Combined with the loose pulse port, inadequate ventilation holes in the hood, and a 650įf muffler stuffed behind the motor and under the stern not 12" from the steering servo... well, you get the point. Hopefully Mokai does too with this new model, dropping a bigger motor in there it is going to need all the help it can get.
Title: Re: directional control rod (from servo)
Post by: happul3 on September 26, 2018, 04:57:48 PM
What did you do to fix the overheating?
And thank you for sharing your experience..

Welcome, Mokamo. I'd say that the first thing about overheating is to be aware of potential issue. I hadn't a clue, running full throttle, paying no attention to the engine compartment. So when the joystick response started to feel very wobbly and I looked up back for the first time, it was already beyond "well done" grade.

Later I installed cylinder head temperature sensor and enlarged air intake - you can find my posts describing those upgrades - and also followed Tom's guidance w.r.t. pulse line. The CHT sensor is truly a must have - it costs very little and requires almost no skill or additional parts to install, while providing the most relevant and the fastest response about engine operating state.  And while the enlarged intake takes few hours of work  (there are several recipes to do that, complete with pictures), it actually reduces the engine temperature below critical. Last but not least, Tom's mechanical steering/throttle kit, which I mentioned earlier is highly recommended as well - you never know when electronics inside a servo might call it quits at high temperature operation :)
Title: Re: directional control rod (from servo)
Post by: mokamo on September 26, 2018, 08:07:05 PM
I think this Mokai was not designed to run all day at Full throttle. It has a run time limit which i think should have been mentioned in Mokai manual. Even with all Tom's upgrade, youll still get to a point where motor will overheat if run continously at full throttle. We are just extending its runtime at full throttle. RPM will still go beyond 275 F if run continously at full throttle. With all Toms upgrade, you will still need to reduce rpm (maybe 2400 rom) at a certain point to cool down the motor. So we really need all these monitoring device so we don't go beyond the limit.
So if they deliver 2018 model, first thing you have to do ideally is install all these temp and rpm monitoring device and dont let oil temp go beyond 275 F. So the ideal way of buying a new Mokai is to go to their factory and use their demo unit all day and see if you can live with the limitations.

Anyone feel free to correct me as im not an expert on engines.
Title: Re: directional control rod (from servo)
Post by: Painlesstom on September 26, 2018, 10:17:40 PM
In stock form, that is correct, but Mokai would never admit there were any limitations so bringing that up with them is a good way to get on their list of phone numbers not to answer.  :D

Oil temp at 275įf is WAY too hot, the engine's life meter is running double time when temps get up there.  :-O

With regards to my upgrades that is not true, setting up an ES-kape with my plenum enlargement, water cooled muffler and hood vent, making a true cold air intake for the carb to breath separate from the flywheel, and running no pull starter installed, I have zero overheating issues and my RPM stays pretty consistent all day if not the same... And I am running a milled high compression EX17 head too. I don't have an oil temp gauge on this engine, but I have the same high compression engine setup in my 2011 and the oil temps rarely go over 235įf. That is full throttle for 10 miles non stop during the summer, heat is not an issue with the right upgrades.
 ;)
Title: Re: directional control rod (from servo)
Post by: happul3 on September 26, 2018, 10:29:23 PM
After this summer I feel confident that it is ok to run my Eskape at 3800-3850 rpm for as long as I want. Next summer I might raise the bar to max, which for me is 4050 rpm. One thing to remember is that the rate at which oil degrades is a steep function (likely exponential) of temperature. Each 20 degrees increase may translate into 2X  faster degradation rate (that's a speculation based on typical chemical reactions). So even if running faster does not damage anything, it does mean disproportionately more frequent oil changes.
Title: Re: directional control rod (from servo)
Post by: Painlesstom on September 26, 2018, 10:49:44 PM
Which is why you should focus on maximizing cooling, and running a good synthetic oil. This is all I run in mine. https://www.amsoil.com/shop/by-product/motor-oil/4-stroke/formula-4-stroke-10w-30-sae-30-small-engine-oil/?code=ASEQT-EA

I'm running 4300-4440 depending on which boat I'm in, can do that all day long without any problems.  \./8
Title: Re: directional control rod (from servo)
Post by: happul3 on September 26, 2018, 11:12:47 PM
Which is why you should focus on maximizing cooling, and running a good synthetic oil. This is all I run in mine. https://www.amsoil.com/shop/by-product/motor-oil/4-stroke/formula-4-stroke-10w-30-sae-30-small-engine-oil/?code=ASEQT-EA

I'm running 4300-4440 depending on which boat I'm in, can do that all day long without any problems.  \./8

 I can't believe I forgot to mention oil. Thanks for reminding us, Tom. Synthetics supposed to run fine at about 50 degrees higher temperatures. I too use amsoil, only slightly different grade:

https://www.amsoil.com/shop/by-product/motor-oil/gasoline/sae-10w-30-signature-series-100-percent-synthetic-motor-oil/?code=ATMQT-EA
Title: Re: directional control rod (from servo)
Post by: mokamo on September 27, 2018, 12:08:23 AM
In stock form, that is correct, but Mokai would never admit there were any limitations so bringing that up with them is a good way to get on their list of phone numbers not to answer.  :D

Oil temp at 275įf is WAY too hot, the engine's life meter is running double time when temps get up there.  :-O

With regards to my upgrades that is not true, setting up an ES-kape with my plenum enlargement, water cooled muffler and hood vent, making a true cold air intake for the carb to breath separate from the flywheel, and running no pull starter installed, I have zero overheating issues and my RPM stays pretty consistent all day if not the same... And I am running a milled high compression EX17 head too. I don't have an oil temp gauge on this engine, but I have the same high compression engine setup in my 2011 and the oil temps rarely go over 235įf. That is full throttle for 10 miles non stop during the summer, heat is not an issue with the right upgrades.
 ;)

An excellent performance result Tom. 10 miles full throttle non stop during the summer and not overheating is music to my ears.
Title: Re: directional control rod (from servo)
Post by: riverman on September 27, 2018, 01:25:18 PM
My opinion don't waste your time with that servo business, get Toms  direct cable steering, it works great and very reliable. Definitely worth the money.     
Title: Re: directional control rod (from servo)
Post by: Painlesstom on September 27, 2018, 02:21:57 PM
Did 32 miles today, full throttle. Direct control is the only way to go, I doubt any stock ES-kape could make the trip I did today without something failing. RPM stayed around 4250 the whole trip, ran like a top. Lots of video coming soon so stay tuned.  \./8
Title: Re: directional control rod (from servo)
Post by: Painlesstom on September 27, 2018, 02:22:53 PM
My opinion don't waste your time with that servo business, get Toms  direct cable steering, it works great and very reliable. Definitely worth the money.   

Thanks for the feedback, glad you're enjoying it!  :)
Title: Re: directional control rod (from servo)
Post by: CC-CODER on September 27, 2018, 06:17:43 PM
We have done a few 20 mile trips this summer at full throttle without any issues. (Subaru's)
One Mokai has an inter-cooler with Tom's exhaust, the other Mokai runs without the inter-cooler, but with Tom's exhaust. The exhaust on the Mokai w/o the inter-cooler was definitely hotter, but both ran great.
Title: Re: directional control rod (from servo)
Post by: mokamo on September 28, 2018, 07:05:57 AM
good to know these positive and negative feedback after adding Toms products. So far no negative feedback yet.





Title: Re: directional control rod (from servo)
Post by: CC-CODER on September 28, 2018, 10:42:00 AM
good to know these positive and negative feedback after adding Toms products. So far no negative feedback yet.

All positive here. Glad I bought mine off Craigslist and had Tom make them reliable. Iíve never had to deal with faulty parts like plastic wear rings or servoís and very happy about it. Doubt if a stock Mokai would perform as well as my 20 mile trips and Tomís latest 32 miles. Probably why so many Mokaiís for sale have less than 10-20 hours on them. Now it is a boat, so I will have some issues down the river. Lol But with customer service like Tomís and the knowledge gained from this forumís members, Iím literally a very happy camper, as seen in my videos. 👍🏻
Title: Re: directional control rod (from servo)
Post by: mokamo on September 28, 2018, 12:15:53 PM
It is really sad that you already know you will have to spend more money after spending 6000.00 to fully enjoy the boat and make it painless. So sometimes you will start thinking to just get a scratched used Mokai and get all Toms upgrade.
Title: Re: directional control rod (from servo)
Post by: CC-CODER on September 28, 2018, 01:20:35 PM
Exactly. Some have had nothing but a pleasant experience with Mokai, but I don't see how. As in most things, I'd rather spend my money towards getting it right the first time. One sand bar...new wear ring. One splash...new servo. And those are the replaceable parts.

After the gentleman from the UK got his pumps stolen out of his garage, I make sure to lock mine in my vehicle, house or somewhere secure. At $1500 each, would probably have to buy another used Mokai to replace. (Times 2 too. Lol) Probably be difficult getting one from Mokai. Plus I'd have to get it rebuilt along with a new wear ring.