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Honda 75 Throttle & gear cable adjustment help needed

C

Calabashman

Member
I've just joined your forum and need assistance with adjusting my throttle cable. At the helm I can move my throttle arm from neutral forward almost 1/2 way to the maximum position before it begins to move the linkage at the carbs. As a result I never reach maxs rpms and I'm just not comfortable running the boat with potential problems brewing. I have the same problem in reverse. I bearly have enought room to engauge reverse. I'm good with mechanical issues but have no experience with outboard motors. Is there someone out there that can assist me with making the correct evaluation and subsequent adjustments? Much thanks in advance. Calabashman
 
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/Honda/Outboard%20Engine/2002/BF75A2%20LRTA%20/SHIFT%20SHAFT/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/Honda/Outboard Engine/2002/BF75A2 LRTA /THROTTLE 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/Honda/Outboard Engine/2002/BF75A2 LRTA /THROTTLE 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/Honda/Outboard Engine/2002/BF75A2 LRTA /SHIFT SHAFT/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.

Hope this was not too confusing.

Mike
 
Mike, thanks ever so much. I appreciate your time & input. I'll begin looking at the areas you've indicated. What scares me initially is my Honda engine & cable controls were transfered from my old boat to tthis one and it's a completely different set-up. for example -- just in front of the engine there is a 2' diameter/loop of excess cables all tied together. Nowever, it shouldn't be a problem because there are no small loops or any bends in the cables before they are fed under the floor boards up to the console. Thanks for your input, I have work to do to check this out.
 
Mike, please bare with me I'm trying but I've found some problems.
First I can't attach photos because of an IE problem on my pc I didn't know I had. I'll work on it because sharing photos could be helpful to me. Do you have a seperate email address I could use to send you photos?
2nd when I open the page of the repair manual I get schematic ok but the part #s don't match up. For example part #2 (starboard photo) is the diaphram connecting rod not the throttle lever. Still looking at the starboard side photo the # 10 part is a short piece of hose on the left of photo. However # 10 in the port side photo does show what could be a cam stop. However, the cam doesn't touch that stop. It stops about 1/4" short.
3rd (Starboard cables) - end of upper cable and lock nut distance is 5/8 not .5" as recommended. Lower cable end to lock nut is 7/8" not .6". Port side cables look perfect.
4th - roller cam in the slot (starborad side) can't get close to the end on the slot. It stops just before the bend in the slot, at least 1/2" short of the end.
5th. (Stb photo) In neutral looking at the 2 < > alignment points my center of the rod is at least 1/4" to the left of center of 2 marks.
I'll wait to hear back from you to see if I can forward photos & take the nex step. Thanks again
 
Internet Explorer sucks and has recently had several security issues. Try downloading Chrome from Google and give it a try. I think you will find it faster and more reliable.

I prefer to keep the pictures etc on the forum, so others can see what is going on and learn as we do.

Mike
 
No problem Mike. I've attached 5 photos each one has a photo ID in photo bottom area.
Photo 1 = throttle in wide open position stb side.
Photo 2 = throttle in wide open position pt side.
Photo 3 & 4 = both sides in neutral position.
Photo 5 also a neutral position.

I'll send 5 more in next mesage. Hope you receive them and they help you understand what I have going on with honda motor. thanks again.
 
Rats, I don't see the photos I thought I send. Here are 5 more and hoping.
Photo 6 = Port lock nut positions
Photo 7 = Port neutral position
Photo 8 = Shows neutral position gap od 1/8 - 3/16".
Photo 9 = Close up of neutral gap
Photo = 10 Shops no gap with throttle in half way position.
 
Mike, just checking to see if you received the 2 posts with 5 photos each. I changed to Chrome like you suggested and was able to select and download them from what I can tell. Each 1 downloaded 100%, I just don't see them anywhere.

Thanks for your help,, have a good one.
 
Do not see them. You have to go into advanced mode and download to this website, then you have to attach to the post. It is not real user friendly...or maybe I am just getting too old. I have been messing with computers since we only could buy a chip and program it in machine language...but maybe I am missing something.

Mike
 
OK Mike I think I may have done it correctly. Very difficult to find "user control panel and my alblums. Never did find the advanced settings. Here are the 10 photos numbered and with a caption that hopefully will help you see what my linkage etc looks like in different throttle positions.
Let me know if you need anything clearer or more info. again thanks for your help. sorry it took so long.
Well, I'm wrong again. They didn't show up here. I'll try again. My photos are in the public photo area and identified as 1 - 10 if I can't link them here.P1080222.jpg P1080223.jpgP1080224.jpgP1080225.jpgP1080226.jpgP1080227.jpg Here are the first 6 4 to follow.
 
Mike it's the pest again sorry. I think I've had a productive day. Between your advice and the expanded repair/owners manual I purchased I was able to make some adjustments to my engine. Working primarilly with the throttle cables I was able to adjust them to where I think they ought to be, or damn close. Look at the 3 new photos and see if you agree. If that wasn't enough I muff tested the engine and damn if it doesn't run better. It shifts much smoother and easier, and It starts much better than ever. After it warms up there is no caughing or sneezing except when I'm accelerating. Soon as it reaches speed it smooths right out. I also did the spark plug test and the engine slowed when I removed each of the plugs individually. I think #1 & #4 had the biggest change in speed. I also checked my oil level and when oil was cold it is right at the top of the marks for full. Maybe I should remove some?

The only thing I'm not sure about is in the photo of the throttle cam @ WOT. The roller isn't quite at the end of the slot. Let me know if that matters etc. I didn't understand what I was supposed to do to adjust it. Please let me know what you think and if there is anything else I should look at or adjust. Thanks again for all of your assistance, you were great to help me.

P1080232.jpgP1080233.jpgP1080235.jpg
 
I think you are as good as you are going to get.

I do recommend that you lower the oil level to about 1/4" below the full mark.

As for the sneezing...I see that you do not have the limiter caps on your carburetors. Make sure that they are 1 7/8 turns out. Then you might turn them out about 1/8 turn more to see if the sneezing goes away.

Of course, vacuum balancing might also help.

Try the idle mixture adjustments and some Sea Foam in your fuel and see if things get even better.

Congratulations for hanging in there. Just think...you learned more about computers and engines.

Enjoy your boating!

Mike
 
Mike you'll won't believe what I just found.!! ALL of the pilot screws were set @ or about 3 full turns open!! After warming the engine up for 10 minutes I adjusted them down to the 1 7/8 turn point and let it run. In doing so my idle speed decreased to where it was barely running and running rough so I increased it to about 900 rpms where it evened out a lot. There definitely was more hesitation & coughing at that point. I increased them all to 2 full turns and it smoothed out some but not a lot, in fact it was actually running better with 3 full turns than it is now. Interesting. I left it at those settings (2 full turns and idle @ 900rpms)for tonight wanting to get this information to you so you could think about it. Let me know what you think please. thanks a million.
 
I do not know.

The specs for the rpm are 950 plus/minus 50 adjusted in the water. I usually adjust to almost 1000 rpm on a hose and once I get it to the water for final checks, the idle settles down.

Even the 90 HP idle mixtures are only 2 1/4 turns out.

In general, if you have to adjust something way out of spec, it is compensating for something that is not right.

Possibly, whomever cleaned the carbs (since they did not adjust the cables correctly) did not clean all the transition passages in the carbs. The other possibility could be the carbs are way out of balance. Another could be the valve clearances are not correct.

I would start by increasing the idle at least another 50 -75 rpms and try readjusting the idle mixtures.

You just have to eliminate the possibilities to find the problem.

I hestitate to say "it is what it is". I am stubborn that way.

Mike
 
Ya, you can probably tell, I'm that way also. I'll take your advice and see what happens. Worst case would it hurt to get them back up to almost 3 turns if this doesn't change anything? Thanks, Have a good night. C
 
I do not know what it would hurt.

If you run it that way, check the spark plugs after you run it for a while and see how they look. That might tell you something.

Mike
 
Mike I'm thinking of replacing my 4 pilot screws. I don't know what good or bad ones look like but if it won't break the bank I'd like to try new ones for a fresh start. Where would you go to purchase them. I looked here but didn't find them.

also what would you day the book value of a 02 & 04 90 hp Honda with low hours would be? I've seen 1 of each that might be a good alternative to consider. Thanks
 
Most likely, replacing them would be a waste of money. They typically do not go bad. They do get damaged, mostly when people remove them. I think they run about $8 each.

A better investment would be a carburetor manual from Helm. http://www.helminc.com/helm/product...=&from=result&Style=helm&Sku=TM044&itemtype=N

It has great step by step on how to clean your carburetors. They also have colored pictures showing the fuel flow and explain what the idle mixture screws, etc do. Following the steps, you will be assured that the transitional passages are good.

The other would most likely be an investment in a new jet set for each carburetor, if any of them are plugged up.

As for the book value, I would check nadaguides.com. http://www.nadaguides.com/Boats/Outboard-Motors

It will at least be a reference.

Mike
 
Thanks Mike, The reason I am thinking about replacing the pilot screws is as I looked at them on the bench I "thought" that 1 of them looked a little crooked toward the tip, like it had been bent or dropped along the line. Running the engine afterwards it seemed ok but was coughing a bit more than before even when I tested the # of pilot screw turns from 1-7/8 to 3. nothing changed noticeably in terms of performance. I'm going to water test it in the inter-coastal ww. Thanks for all your help.
 
Mike with regard to getting the carburetor manual, how much dis-assembly could I do without having to purchase special electronics/vacuum test equipment? Can it be completely disassembled & reassembled to running order with out them? Of course I'd buy the appropriate gasket sets etc as I went along.
 
Mike, just so you know, I just went to HELM INC. and pulled the trigger on the carb manual. I would never have known they had one if not for you.
Thanks,
jimmyd

PS as an aside to the above conversation, I would wholeheartedly agree with you that buying new idle mix needle valves will not solve his problem. When these needles are damaged from over-tightening, they usually get a little "step" in them requiring that they be backed out LESS, not MORE. So, if Calabashman is getting an improvement by backing them out further than spec then I would venture to say you are also correct in saying that a compensation is being made for a different problem, most likely in the carb passages or jets. Although, checking the valve train is a good idea.-jd
 
AHA! Finally caught you being wrong about something. You DID already mention valve clearances. See post # 15. Not bad though that when you're wrong, you're right:)
 
I can tell you both are good friends. Jimmy d, thanks for your comments as well. As you can tell I know very little about outboards but thanks to Mike I have learned a lot and will take his advice and purchase the Carb manual. I'll make disassembling, cleaning and reassembling a winter time project in my garage. Jimmyd I'd be interested in hearing how you make out with your carb repair work.

Now for Mike and my in water test. Wow, what a difference a few adjustments make. I had the pilot screws set at 2.5 turns just as a starting point. I'll gradually turn them down toward normal to check performace variables etc. 1st. the shift cable adjustment is perfect and for the first time in a 2years I was able to get to 5500 rpms easily. As for the coughing or hesitation it's gone completely when not idling. As soon as it warms up it smooths right out. I could not be more pleased and I have you to thank. Now, if I didn't have that flat tire in the parking lot of the ramp I was at it would have been a perfect day. Ever had a bunch of angry boaters yelling at you to get you _____ boat off the ramp? Just the stress I needed to end my day. Mike thank you ever so much, I appreciate everything. Calabashman
 
Sorry you finished your day on a less than perfect note.



On the other hand, I am glad things are improving.

if you can borrow some vacuum gauges, balancing the carbs might fix your idle problem. Oh yeah, be sure to check the valve clearances too (thanks, jimmy!). Oh forgot one more thing (and yes, Jimmy, I may have said it before)....make sure the engine is not running cold. The temperature at the should be near 180 deg F when the engine is fully warmed up. If it is running a lot cooler, then replace the thermostat and that alone could improve your idle.

Mike
 
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Thanks Mike, thanks, you've given me 3 more thinks that could improve performance. I'll check around to see if someone has a set of Vacuum gauges. I'd like to be sure they (and the valves) are set correctly. I can't tell you how good it feels to know that my boat is running more reliably. Great piece of mind. Calabashman
 
Sorry Mike - I'm still trying to learn here. Just when you think I've stopped asking questions I show up with 2 more.
1. - I've been thinking about your suggestion to remove and clean the 4 carbs. Once disassembled I'm assuming I would soak them in carb cleaner of some type to remove any/all junk in the jets and small areas of the fuel lines etc. I certainly don't want to start scraping the inside surfaces. My thinking is I'd soak them in a strong solution of Sea Foam (?) after I remove all non-metal parts. So my question comes down to: How strong a solution of sea Foam (?) would you soak them in and for how long?

2. - The 16 oz can of Sea Foam states: 16 oz will treat 8 - 25 gallons of gas. That's a big spread. At 8 gallons that's a ratio of 64:1 and at 25 gallons it's 200:1. My 2nd thought is to set up a small tank of gas (1 gal) with a strong mixture of SF and run that through the engine as described. That also brings me to the ? of how strong as solution should I use.

Thanks again, Hope you have a great day. calabashman
 
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