Idle speed is too low after installing new throttle cable. Tohatsu 50hp

Sinclare

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Aug 14, 2012
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Tohatsu M50D2 serial # 62709 50hp

I just installed new throttle and shift cables, started the engine and the idle seems too low. It tends to drop below 800 rpm and then die. The throttle cable clevis fits in comfortably onto the throttle lever, so there's no tension forcing the throttle lever. (I received cable installation intructions on this board from Paul, TLDI, Certified Technician, Buffalo, NY) So Paul, if you're out there, I could use some more help.

Before I installed the cables, the engine started fine while in gear (because of a broken shift cable) and it idled in gear. Although, this was with the choke in for a moment. Sounds to me like I need to turn an idle screw. What do you think and where is it located? Thanks.
 

Sinclare

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Re: Idle speed is too low after installing new throttle cable. Tohatsu 50hp

I installed new spark plugs and it idles ok, still a bit low, slightly less than 800 rpm. It's a struggle idle. No water from the "pee-hole" during a five minute run with ear muffs. Increased rpm's to 1,200 and slowly backed off to idle. Smooth at 1,200.
 

pvanv

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Re: Idle speed is too low after installing new throttle cable. Tohatsu 50hp

The idle stop screw is located on the top carburetor. It affects all 3 carbs in synchronization. Proper idle is set with the motor fully warmed, preferably in the water, as opposed to on muffs, and you want to check it both in N and in gear (2 different rpm's, of course). Full procedure is in the Factory service manual, available from any dealer, including me. Might not hurt to run through the complete link and sync section in the manual, just to be sure everything is OK.

I would be concerned about the lack of a telltale stream. If your garden hose pressure is low, that could possibl;y cause that, but in that case, you are probably not cooling sufficiently. Does it pee OK in the water?

Any 2-stroke will idle a little weird without a load on it. Testing in gear in the water may well be smoother.
 

Sinclare

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Re: Idle speed is too low after installing new throttle cable. Tohatsu 50hp

Thanks Paul. I expect to launch it soon and will check it out again according to your instructions. I did feel air come out of the "water check port" but didn't want to run it any further after that. Maybe not enough water pressure from my garden hose. From the previous owner, I have a Clymer Tohatsu 2.5 - 140hp shop manual covering the years 1992-2000.

Have to wait for the repair of my tow-tug. Had a rebuilt transmission recently installed by AAMCO. Drove it about ten+ miles and the engine raced when attempting to shift from 2nd to 3rd gear. They sent the transmission back to their reman facility. GMC Savana 1500, 5.3 engine. Bought a "lifetime" warranty from them.
 

pvanv

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Re: Idle speed is too low after installing new throttle cable. Tohatsu 50hp

You are feeling exhaust from the telltale; The pump must be repaired. We always prefer the Factory manual to the aftermarket manuals. These are available from any dealer, including me.

Water pump repair kit. Includes all parts needed to replace water pump. Fits: 40/50D & 40/50D2 2-stroke models. Part# 3C8873223M. $60.83

SERVICE MANUAL : 3 & 4 CYLINDER 2-STROKES. Covers all 3 & 4 cylinder 2-stroke models. Part# 003-21036-1. $45.00
 

Nuaticocat

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Re: Idle speed is too low after installing new throttle cable. Tohatsu 50hp

My honda won't flow from the indicator hole with my garden hose, even with a new pump master kit installed. I stuck it in a trash can full of water and it flowed fine. Just not enough flow from the earmuffs. My buddys Merc is the same way , as is my small 25 hp merc.
 

Sinclare

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Re: Idle speed is too low after installing new throttle cable. Tohatsu 50hp

What is the size/hp of your Honda motor? Is your trash can metal and of a "regular" size?
 

Nuaticocat

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Re: Idle speed is too low after installing new throttle cable. Tohatsu 50hp

It is a 50 hp 4 stroke. Regular old plastic trash can. I keep the hose in it to keep the water cool.
 

pvanv

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Re: Idle speed is too low after installing new throttle cable. Tohatsu 50hp

My honda won't flow from the indicator hole with my garden hose, even with a new pump master kit installed. I stuck it in a trash can full of water and it flowed fine. Just not enough flow from the earmuffs. My buddys Merc is the same way , as is my small 25 hp merc.

Your hose is not providing enough water. Period.

And this post was about a completely different motor, BTW :)
 
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