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Honda 75 trouble with throttle

 
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louxwe



Joined: 03 Sep 2018
Posts: 15
City/Region: Niceville
State or Province: FL
C-Dory Year: 2006
C-Dory Model: 22 Cruiser
Vessel Name: C-Falcon
Photos: C-Falcon
PostPosted: Mon May 13, 2019 10:26 pm    Post subject: Honda 75 trouble with throttle Reply with quote

I have had my boat for several months now and it seems like I have to push the throttle level farther and farther down to get enough throttle. Seems like it gets a bit more each time and now even with the throttle level all the way forward it still is not at max rpm's. I am new to outboards, is this just some kind of loose bolt or cable? Does it work like a bike brake cable, is there somewhere I can just pull the cable tight again and tighten the bolt. This happened over a relatively quick time frame so I don't think it is just normal cable stretch. Any other advice on what to check?

Thanks, Bill
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tsturm



Joined: 01 Nov 2003
Posts: 775
City/Region: Soldotna
State or Province: AK
C-Dory Year: 2003
C-Dory Model: 25 Cruiser
Vessel Name: JMR TOO
Photos: JMR-TOO
PostPosted: Tue May 14, 2019 9:50 am    Post subject: Re: Honda 75 trouble with throttle Reply with quote

louxwe wrote:
I have had my boat for several months now and it seems like I have to push the throttle level farther and farther down to get enough throttle. Seems like it gets a bit more each time and now even with the throttle level all the way forward it still is not at max rpm's. I am new to outboards, is this just some kind of loose bolt or cable? Does it work like a bike brake cable, is there somewhere I can just pull the cable tight again and tighten the bolt. This happened over a relatively quick time frame so I don't think it is just normal cable stretch. Any other advice on what to check?

Thanks, Bill


Take the engine cover off, find cable, note the position of the lever the cable attaches to, at the helm move the throttle lever to WOT, go back to engine & make sure lever goes to WOT also(might be 2 arrows to line up, on the lever & something stationary) if all is well in the cable, a recent prop change? more weight? Ck compression?
A factory repair manual might be a good investment.
Wink
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BrentB



Joined: 15 Jul 2006
Posts: 4267
City/Region: Greenwood
State or Province: IN
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PostPosted: Tue May 14, 2019 5:50 pm    Post subject: Reply with quote

From
http://www.marineengine.com/boat-forum/showthread.php?402931-Honda-75-Throttle-amp-gear-cable-adjustment-help-needed


you have to figure out if the problem is on the motor itself or in the throttle connection to the motor and/or shifter.

Disconnect your throttle cable from the throttle lever on the engine. Part #2 http://www.boats.net/parts/search/Ho...AFT/parts.html

Then manually advance the throttle lever, part #2 with your fingers and see if it will go all the way to touch part #10. Check the other side of the engine. When the throttle lever is touching the throttle stop, then on the other side of the engine, the roller cam should be all the way to the end of the slot inside part #17. http://www.boats.net/parts/search/Ho...CAM/parts.html

If the throttle lever touches and the roller cam goes all the way up the slot, then you just have to adjust how the throttle cable is connected to the engine and/or the shifter.

If the roller cam does not go all the way to the top, then you will have to adjust cables #1 that go from the port side to the starboard side of the engine. These sometime are not adjusted right after someone removes the carburetors.

When you get the throttle lever to touch the stop, then reconnect the throttle cable from the shifter as follows.


At idle (shifter in neutral), the roller cam that rolls inside part #17 on the other side of the motor http://www.boats.net/parts/search/Ho...CAM/parts.html should be centered at the little arrow near the bottom of the slot.

Then you have to adjust the brass connector at the end of the shift cable to just fit in the inside hole on the throttle lever Part #2 http://www.boats.net/parts/search/Ho...AFT/parts.html. Do not put it in the hole at the end of the throttle lever.

If everything is ok at the shifter and you have the correct shifter, the adjustment above should give you full throttle.

You can see if you actually have full throttle by either checking the throttle stop or looking at the cam on the lever on the bottom carburetor.

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louxwe



Joined: 03 Sep 2018
Posts: 15
City/Region: Niceville
State or Province: FL
C-Dory Year: 2006
C-Dory Model: 22 Cruiser
Vessel Name: C-Falcon
Photos: C-Falcon
PostPosted: Wed May 15, 2019 12:33 pm    Post subject: Cable looks okay? Reply with quote

I popped the hood and move the throttle selector and full forward and it moved the throttle pulley all the the way 100% up until it hit a physical stop, so it seems to be moving the throttle to wide open okay.

Now I am concerned that I may have a spun prop after doing some more investigating. I did hit a rope recently, I took the prop off and looked at everything and it seemed to be okay, not sure how to test if it is spun prop, or partially spun. I am thinking that maybe the prop stays in position until it gets to high rpms then maybe it starts spinning. Just seems like I used to/should be going faster at the given throttle. Hard to tell since it is only a 75hp and usually would be powered by a 90hp. Just seems like I was topping out at 23knots when I first got her but was maxing out at 17-18 last time, I did have more weight but not that much more.

Bill
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BrentB



Joined: 15 Jul 2006
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City/Region: Greenwood
State or Province: IN
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PostPosted: Wed May 15, 2019 7:34 pm    Post subject: Reply with quote

sure sounds like it is spun
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Avidmagnum12



Joined: 23 Mar 2013
Posts: 446
City/Region: Ocklawaha
State or Province: FL
C-Dory Year: 2011
C-Dory Model: 25 Cruiser
Vessel Name: C-Otter
Photos: C-Otter
PostPosted: Wed May 15, 2019 8:33 pm    Post subject: Reply with quote

Iíve spun 4 hubs in the last 9 months without hitting anything. . Iíll post why on its own link in the near future. If you use a punch to dimple both the inner hub and the prop inline with each other and after use if they no longer line up the prop is spun. When mine were spun I could only do about 8 mph max. But that is on a 25 with 200 hp Yamaha.

On my 22 the speed would drop quite a bit with a heavy stern load. A permatrim helped a lot under the same conditions.

If you have a spar prop you could put it on and see if that helps. Should always have a spare anyway. But that said.... I spun two hubs in one day! I now carry two spare props. 😇

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Tom and Joyce Schulke

2011 CD 25 "C-Otter" 07/2015 to present
2011 CD 25 "My Girl" 06/2015 renamed C-Otter
2004 CD 22 Commuter "Out2C" 03/10 to 06/15
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thataway



Joined: 02 Nov 2003
Posts: 16856
City/Region: Pensacola
State or Province: FL
C-Dory Year: 2007
C-Dory Model: 25 Cruiser
Vessel Name: thataway
Photos: Thataway
PostPosted: Wed May 15, 2019 9:19 pm    Post subject: Reply with quote

What is the RPM you are seeing at the wide open throttle? In my experience with a spun prop, you will not get on a plane.

2 spun hubs in one day? New record!

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Bob Austin
Thataway
Thataway (Ex Seaweed) 2007 25 C Dory May 2018
Thisaway 2006 22' CDory November 2011 to May 2018
Caracal 18 140 Suzuki 2007 to present
Thataway TomCat 255 150 Suzukis June 2006 thru August 2011
C Pelican; 1992, 22 Cruiser, 2002 thru 2006
Frequent Sea; 2003 C D 25, 2007 thru 2009
KA6PKB
Home port: Pensacola FL
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louxwe



Joined: 03 Sep 2018
Posts: 15
City/Region: Niceville
State or Province: FL
C-Dory Year: 2006
C-Dory Model: 22 Cruiser
Vessel Name: C-Falcon
Photos: C-Falcon
PostPosted: Sun May 19, 2019 9:21 am    Post subject: Reply with quote

I took her out Friday, at full wide open throttle I hit about 5200-5300 rpm and reached around 21 knots, this was dead flat calm with no wind or waves and only me in the boat, but an okay amount of stuff. This currently is with an aluminum solas 3 blade 13.5 diameter 15 pitch. on a 22 cruiser. Seems a bit slow, one time I looked down and saw the rpms jump up to just over 6000 rpm but it didn't really sound like the rpms jumped, I pulled the throttle back and then went back to wide open and it sat at 5200. On the way back in the afternoon wind was at my back but waves picked up and was choppy so really wasn't able to get full wide open got up to just over 5000 a few times but was only doing18-19 knots uncomfortably.

Every now and then it just felt like it was losing its bite on the water and didn't drive through as much, but it held 5200 and 20-21 knots in flat pretty well, but loaded with wife (100lbs) and two small kids it was topping out at 17-18 knots, maybe just too much weight in back.

I think if the prop is spun it may just be a little slip on very high loads if that is possible. Not sure. Since I don't have a spare prop anyway thinking of buying a solas new Saturn 13.5 15 pitch 3 blade and keeping this one as a back up. See if that gives any better performance.
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thataway



Joined: 02 Nov 2003
Posts: 16856
City/Region: Pensacola
State or Province: FL
C-Dory Year: 2007
C-Dory Model: 25 Cruiser
Vessel Name: thataway
Photos: Thataway
PostPosted: Sun May 19, 2019 11:07 am    Post subject: Reply with quote

I doubt if you have a spun hub. Honda calls for 5000 to 6000 RPM for the 75. I prefer to see it in the 5500 range. A SS prop may do it. ($$$)...The 15" pitch is "normal" for the 22 and the 90 hp. The only difference is at top end speeds, so cruising speeds are OK.

You are not too far off with speed--18 knots equals just under 21 mph and 22 knots a little over 25 mph.

Also the question about motor height. Is the antiventillation plate right on the surface of the water?
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ssobol



Joined: 27 Oct 2012
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City/Region: Leesburg
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C-Dory Model: 22 Cruiser
Vessel Name: SoBELLE
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PostPosted: Sun May 19, 2019 1:35 pm    Post subject: Reply with quote

My BF90D has the stock Honda 13.5x15 AL prop. It'll give ~29 mph at ~5600 rpm in the right conditions. But the boat has to be trimmed correctly.

Also, if you can't get the right speed you won't get the right WOT rpm. WOT rpm is not an absolute value. It depends on the operating conditions. In my boat at a high aft load with the trim tabs all the way down, there is no way I will get the same speed and WOT rpm as when the boat is light and the tabs are up.

There is a feedback loop there. The propeller speed rpm increases, the propeller loads up, the boat speed increases, which unloads the propeller, which increases rpm, which loads the propeller, which increases boat speed, which unloads the propeller, etc. Eventually an equilibrium is reached for the current engine power level with a certain rpm and speed.
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tsturm



Joined: 01 Nov 2003
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PostPosted: Sun May 19, 2019 7:22 pm    Post subject: Reply with quote

ssobol wrote:
My BF90D has the stock Honda 13.5x15 AL prop. It'll give ~29 mph at ~5600 rpm in the right conditions. But the boat has to be trimmed correctly.

Also, if you can't get the right speed you won't get the right WOT rpm. WOT rpm is not an absolute value. It depends on the operating conditions. In my boat at a high aft load with the trim tabs all the way down, there is no way I will get the same speed and WOT rpm as when the boat is light and the tabs are up.

There is a feedback loop there. The propeller speed rpm increases, the propeller loads up, the boat speed increases, which unloads the propeller, which increases rpm, which loads the propeller, which increases boat speed, which unloads the propeller, etc. Eventually an equilibrium is reached for the current engine power level with a certain rpm and speed.


Any prop that comes in a box that says Honda on it is a "stock Honda prop" you need to be able to make the WOT rpm range your engine is designed for with any (reasonable) load, or you are lugging the engine. If your 13.5X15 will only make 5600 rpm you might try a 13p?
Beer Wink
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louxwe



Joined: 03 Sep 2018
Posts: 15
City/Region: Niceville
State or Province: FL
C-Dory Year: 2006
C-Dory Model: 22 Cruiser
Vessel Name: C-Falcon
Photos: C-Falcon
PostPosted: Fri Jul 05, 2019 9:28 pm    Post subject: Reply with quote

Hmm, so I have been playing around with this, took the prop off and inspected everything, thought maybe I just didn't have it trimmed right or something. Last several times I took it out with just myself and it seemed to run good, was running just under 6000 RPMS 5800-5900, pretty steady and with pretty flat conditions in the bay was causing along 20-23 knots WOT. Took it into the gulf and it seemed to run fine. Took the kids on a tubing trip the next time and was able to pull them and drove just fine. Then last night I had 3 adults and 4 kids, a bit of a heavy load for me and when I got up to full higher speed it felt like the RPMs went well up to 6500 to 7000 and the power just stopped, with a bit of vibrations... idled down and ran it at 4000 rpm running just above planing speed, but anytime I throttled up it did the same higher RPM and no power. Tried again today with just me in the boat and it ran better up to about 17 knots but then at the higher speeds it over reved and didn't seem to have much power. Is it possible to just sort of spin the hub.... seems like it is sort of holding but when I am heavily loaded or high rpm it feels like maybe it is breaking loose? Is this possible or when you spin a hub its totally all or nothing. Just hoping its just a spun hub and not something more serious.
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Sea Wolf



Joined: 01 Nov 2003
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City/Region: Redding
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PostPosted: Sat Jul 06, 2019 1:42 am    Post subject: Reply with quote

louxwe-

Sounds like you've got a spun hub, plain and simple. Take it to a prop shop and have the rubber hub replaced.

Good Luck!

Joe. Teeth Thumbs Up

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"Most of my money I spent on boats and women. The rest I squandered'. " -Annonymous
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