RPM problems on throttle - Please, can you help?

[Hank Bass]

I have a 1983 Johnson 110hp V4. My problem is that I can't adjust the RPM's lower than 950-1000. I've tried the linkage adjustment but the little nut is completely backed off and the rubber end on the part that hits against the stop is about 1/4 to 1/2 inch short of reaching it. I can manually push it and the RPM's drop to about 850 or so. Then when I rev it up to 2000+ and go back to idle it's back up to 950 -1000.

The throttle cable is not binding that I can tell and I did lube it with WD40 at the motor end. I also used throttle body lube spray on all the linkages but no luck. I didn't have this problem before. What could have changed? I know I should be able to drop the RPMs lower than 850, to maybe 500 or so? I'm not real experienced on carbs/governors so I'm looking for help. Any ideas?

Thanks, Hank Bass

 

[emdsapmgr]

Re: RPM problems on throttle - Please, can you help?

The idle speed is set by adjusting the ignition spark advance, not any linkage on the carbs. Disconnect the throttle cable at the engine end. To lower the throttle, you would back off the large screw on the spark advance lever. That will reduce the timing and cause the idle to go down. That engine idle should be 650-750 rpm, set when the boat is floating in the water and is in forward gear. Once the engine idle is set, then you may need to re-adjust (then reconnect) the throttle cable at the engine end.

 

[Hank Bass]

Re: RPM problems on throttle - Please, can you help?

The idle speed is set by adjusting the ignition spark advance, not any linkage on the carbs. Disconnect the throttle cable at the engine end. To lower the throttle, you would back off the large screw on the spark advance lever. That will reduce the timing and cause the idle to go down. That engine idle should be 650-750 rpm, set when the boat is floating in the water and is in forward gear. Once the engine idle is set, then you may need to re-adjust (then reconnect) the throttle cable at the engine end.

Captain, thank you for the input. I just want to let you know that I tried going counter-clockwise on the big screw that controls the advance with no results. Now I did not try this with the linkage disconnected, would that make a difference? If I manually push the advance linkage to the stop, it does lower it only about 100 RPMs but not enough. Here's another question: Does the advance linkage need to hit the stop or can it be just somewhere close? Sounds like you're spot on but just wanted to make you aware of the situation. Am I going the right way backing the screw off or should it be clockwise? Kinda' lost right about now, but appreciate all the help.

 

[emdsapmgr]

Re: RPM problems on throttle - Please, can you help?

A couple of things. 1. Make sure that the carb roller is not touching the throttle cam when at idle. You should be able to slide a thin pc of paper between that roller and the metal cam. That will insure that your throttle butterflys are absolutely closed at idle. 2. It is very likely that the throttle cable may not be adjusted properly at the engine end. Sometimes they won't let that spark lever go backwards enough to retard the timing enough for a proper idle, so disconnect it while you are making adjustments. 3. As you back out that large screw on the spark lever, the lever should move rearward, along with the link arm-pushing the timer base backward, thereby retarding the spark. If your spark advance screw won't unscrew (counterclockwise) any further, that's a problem. It is possible to do a simple test when you have the engine idling in the water. Disconnect the spark link rod (pop that ball out of the socket) and manually move that timer base rearward and while check your rpm's on the tach. 4. The screw on the spark advance lever is the idle screw and the rubber cap on the end should rest/stop on the side of the crankcase. 5. The screw with the rubber cap on the top of the block is the high speed timing adjusment and a normal owner should be making any adjustments to that setting.

 

[DargelJohn]

Re: RPM problems on throttle - Please, can you help?

Ok, If you have adjusted the spark advance arm, as part of setting the idle, your spark advance is now out of adjustment. Spark Advance is only set @ WOT. You can follow this procedure to reset the spark advance...
http://forums.iboats.com/showthread.php?t=228183

If you can manually push the linkage to the desired RPMs, then your throttle cable needs to be adjusted. Loosen the bolts (circled in green) that anchor the plastic, cable adjustment wheels. Rotate the throttle wheel away from you (tightening) (red attaches throttle). Turn one revolution and check the idle stop to see if the slack is being taken up. Keep adjusting until you reach the desired idle.
On water muffs, should be 900-1000.

 

[wilde1j]

Re: RPM problems on throttle - Please, can you help?

An OEM shop manual would save a lot of screwing around.

 

[Hank Bass]

Re: RPM problems on throttle - Please, can you help?

Darjel Dohn, thanks for the input. Something you wrote may or may not apply. You said that with muffs on revs should be 900-1000.....that's what I've got when I started trying to adjust the idle. Does the engine being in the water slow the RPMs down? Not too experienced in all of this so forgive the question. If it does, then maybe I've got it to where it needs to be?

Thanks.

Hank Bass

 

[DargelJohn]

Re: RPM problems on throttle - Please, can you help?

Darjel Dohn, thanks for the input. Something you wrote may or may not apply. You said that with muffs on revs should be 900-1000.....that's what I've got when I started trying to adjust the idle. Does the engine being in the water slow the RPMs down? Not too experienced in all of this so forgive the question. If it does, then maybe I've got it to where it needs to be?

Thanks.

Hank Bass

Yes, The lower unit in the water creates back pressure on the exhaust, causing RPM's to be about 100 less.

So, 900 RPM's on the muffs ~ 800 RPM's in the water.

 

[emdsapmgr]

Re: RPM problems on throttle - Please, can you help?

The engine rpm's will significantly reduce when the engine is idling in the water. The exhaust exits nearly 18" under water, so it really has to work to keep an idle when the boat is floating. It can make as much as 400-500 rpm difference. You can't set the idle correctly unless it is floating in the water-in gear. Any other idle rpm settings are irrelevant/meaningless. Hank, perhaps you should provide us with the model number off that engine. OMC did not make a 110 hp engine in 1983. The engine-mounted throttle linkages of an 83 model are not exactly the same as a typical 110-in the picture provided by Dargel, above.

 

[boobie]

Re: RPM problems on throttle - Please, can you help?

Wilde1, I liked the pun which is true.

 

[Hank Bass]

Re: RPM problems on throttle - Please, can you help?

The engine rpm's will significantly reduce when the engine is idling in the water. The exhaust exits nearly 18" under water, so it really has to work to keep an idle when the boat is floating. It can make as much as 400-500 rpm difference. You can't set the idle correctly unless it is floating in the water-in gear. Any other idle rpm settings are irrelevant/meaningless. Hank, perhaps you should provide us with the model number off that engine. OMC did not make a 110 hp engine in 1983. The engine-mounted throttle linkages of an 83 model are not exactly the same as a typical 110-in the picture provided by Dargel, above.

Captain, I will try to post a picture tomorrow when I go back out to the boat. Would the serial number do? Where do I get the model number, the tag on the lower unit is old and damaged. Thanks for all the help, will be in touch, at least with the pic but here's the numbers off a round little plug that looks kinda' like a freeze plug. It is: J0004799, also found this on it: E100WTPLYJ0430181. Looked this number up and I think it's a 100 hp.??

Anyway, a pic or pics probably would help. Will post when I get them.

Thanks again.

Hank Bass

 

[emdsapmgr]

Re: RPM problems on throttle - Please, can you help?

Hank, the engine serial number(s) does not go anywhere, but from the model number it looks like the engine is a 1996 100 hp crossflow.

 

[DargelJohn]

Re: RPM problems on throttle - Please, can you help?

Hank, the engine serial number(s) does not go anywhere, but from the model number it looks like the engine is a 1996 100 hp crossflow.

If it turns out to be a 1996, then my pic should be correct. The pic is of my '96 88SPL.

 

[Hank Bass]

Re: RPM problems on throttle - Please, can you help?

Captain, I looked on this link and it says 1989 100hp on the E100WTPLY number mine has on it. It's identified as a Johnson/Evinrude "commercial". Wonder what that means?
http://www.obparts.com/years/johnsonevinrude.html

Will shoot pics this afternoon when I get off work.

Regards,

Hank Bass

 

[Hank Bass]

Re: RPM problems on throttle - Please, can you help?

DargelJohn, here's a link that may coincide with my model number that I found on the engine which is E100WTPLY, the rest of it was J0430181 but that was not on the listing. It's classified as a Johnson/Evinrude "commercial". Taking pics this afternoon. Thanks for the help and suggestions.

http://www.obparts.com/years/johnsonevinrude.html

Regards,

Hank Bass

 

[DargelJohn]

Re: RPM problems on throttle - Please, can you help?

DargelJohn, here's a link that may coincide with my model number that I found on the engine which is E100WTPLY, the rest of it was J0430181 but that was not on the listing. It's classified as a Johnson/Evinrude "commercial". Taking pics this afternoon. Thanks for the help and suggestions.

http://www.obparts.com/years/johnsonevinrude.html

Regards,

Hank Bass

Hank, I can't match your number exactly. But, here is an exploded view of a 1989 Evinrude 100 Commercial motor. Looks just like my '96 88SPL.
http://www.boats.net/parts/search/BRP/EVINRUDE/1989/E100WTLZ 1989/CYLINDER & CRANKCASE/parts.html

 

[Hank Bass]

Re: RPM problems on throttle - Please, can you help?

Hank, I can't match your number exactly. But, here is an exploded view of a 1989 Evinrude 100 Commercial motor. Looks just like my '96 88SPL.
http://www.boats.net/parts/search/BRP/EVINRUDE/1989/E100WTLZ 1989/CYLINDER & CRANKCASE/parts.html

DargelJohn, am hoping pictures will attach to this post. Should be decent quality. Let me know what you think. Thanks.

Hank Bass
Friendswood, TX

 

[Hank Bass]

Re: RPM problems on throttle - Please, can you help?

Hank, the engine serial number(s) does not go anywhere, but from the model number it looks like the engine is a 1996 100 hp crossflow.

Captain, I just posted pics on DargelJohn's post just now. To me, it sure doesn't look like a 1996 model, think it's a 1984 (since the model number had a V instead of a Y on the end) like obparts.com had it listed. You can see that there is no more space for the little nut to go on the linkage. On one of the pics you can see the advance does not hit the stop but cannot adjust it with the throttle cable. What do you think?

Hank Bass
Friendswood, TX

 

[Hank Bass]

Re: RPM problems on throttle - Please, can you help? SOLVED

Re: RPM problems on throttle - Please, can you help? SOLVED

Thanks to all, my problem(s) got solved. The RPM's with muffs were 900-1000. When I did the adjustment for the advance, it brought RPM's down to 700 and with the boat in forward down to about 600. THAT WILL WORK FOR ME.

Thanks for all the assistance, there is a lot of knowledge on this board. Saved me a lot of headaches......not to mention $$$.

Regards,

Hank Bass

 

[emdsapmgr]

Re: RPM problems on throttle - Please, can you help? SOLVED

Re: RPM problems on throttle - Please, can you help? SOLVED

Good Deal! Happy boating.