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Tohatsu 6 hp throttle linkage help needed

C

cptmclark

New member
Hello,

I just got my engine back from repair, and found the throttle handle linkage loose. (Two hour drive each way to thee closest warranty shop). I see it needs to have the attachments placed properly on the upper ends, but can't see without disassembly if the handle ends also need to have the little cylinders installed in slots in the "wheel". If so, how to get to it. I need some detailed instructions for this job.

Secondly, the throttle rod from the carburetor to the rotating wheel simpy falls out of the wheel end, and I don't see how it's supposed to be retained.
The parts schematics I found don't help.

Thank you for any help. Seems it should be an easy job once you know how.
 
Assuming you have a 4-stroke tiller model. such as an MFS6B or 6C.

The throttle is cable-operated. Not sure what you mean when referring to "throttle handle linkage". Apparently whomever last worked on it did not know how it goes together. What work was done? The tiller handle and associated "external" parts should be connected as in the following diagram:
002-21046-0AG_FIG10.jpg
The throttle drum and throttle opener assembles as shown in the following diagram. If assembled wrong, it is indeed possible that the throttle rod could fall out. Yes, it is an easy job, but the mechanic needs to understand the purpose of the setup; In order for the choke to advance the throttle, the throttle rod needs to be able to advance without the throttle cables moving. That is why the two-piece throttle drum and opener. The following diagram explains how it all goes together. After it's correctly assembled, you may need to adjust the locknuts on the cable to get idle and WOT where they belong, and to remove slack in the cable.
002-21046-0AG_FIG03.jpg
 
pvanv said:
Assuming you have a 4-stroke tiller model. such as an MFS6B or 6C.

The throttle is cable-operated. Not sure what you mean when referring to "throttle handle linkage". Apparently whomever last worked on it did not know how it goes together. What work was done? The tiller handle and associated "external" parts should be connected as in the following diagram ---------By "throttle handle linkage" I'm referring to the cables that run from the tiller handle (where there is an attachement I can't see on a rotating drum), and then to to the top spindle where they attach to another drum, rotating that to work the throttle on the carb through the "throttle rod". I'm likely using the wrong words to describe the parts. Basically is looks logical to me, but I lack the details of the connections of the cables at top and bottom. I now see the connectors at the top and they are now disconnected.
-------------At the bottom, in the tiller, there is another wheel or drum that I see only half of, and that I don't know how the cables are attached to that one. I think one of the cables is loose there, but didn't want to disassemble further without some guidance.
Sorry for so many words to describe this apparently simple contraption. Simple that is, after you've done it once.

View attachment 17620
The throttle drum and throttle opener assembles as shown in the following diagram. If assembled wrong, it is indeed possible that the throttle rod could fall out. Yes, it is an easy job, but the mechanic needs to understand the purpose of the setup; In order for the choke to advance the throttle, the throttle rod needs to be able to advance without the throttle cables moving. That is why the two-piece throttle drum and opener. The following diagram explains how it all goes together. After it's correctly assembled, you may need to adjust the locknuts on the cable to get idle and WOT where they belong, and to remove slack in the cable.
Yes this shows how it goes together at the top, near the carburetor. I don't see the other end of the cables where they attach (or just go around) the wheel or drum in the tiller. Do they have the metal attachments as there are on the other end? If so, how do I access those attach points inside the tiller? Easy no doubt but I don't want to disassemble more than I need to.
---------------------------
Using the second diagram, I suspect that there was some confusion between the rod hole in part 29 and a hole in part 28. 29 seems to be where the rod end goes, but it was hanging loose under the hole in part 28 and, as you no doubt know, it won't stay there. The cable was slack at the top connectors and also on one one of the lower ends where it disappears into the tiller behind a wheel.
----------I suspect I'll need to pull that wheel out (on the end of the "tiller rod" and reattach the cable but I don't know how and need some guidance.

View attachment 17621[Oh, the original work order was to replace a plastic shifter, which was attached to the forward gear shift lever.
Click to expand...
 
Last edited:
Yes, there is a metal T at the end of each cable. Those insert into the drum in the tiller. Likely still in there, but reasonable to reattach if they fell out.

At the top, pay close attention to how the drum and opener fit together. The rod just drops in to the eye. Then the cables drop into the slots. Finally, add some tension to the cables. Not much; just remove the slack. It's possible to get them out of adjustment, but also easy to readjust them.

With the choke OFF, you want the carb to close all the way when the tiller twist is at idle, and open all the way when the twist is all the way to max. If you try to make this adjustment with the choke engaged, you will not be at low speed idle.

Full information is in your Factory service manual p. 3-15. I have it available:
Part #: 003-21034-2
List Price (MSRP): $41.67
 
I'll be off to the lake pretty soon and use your help to (hopefully) complete the job. Concerned about accessing the drim in the tiller without removing the whole tiller rod. Maybe easy to see when I'm back at the engine.

Thank you very much. Hope your winter is finally over in NY.
 
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