Hi guys ... I wandered if anyone on here could maybe be of assistance :-)
I have just purchased a Yamaha 30 twin .. Single carb which needs a bit of tlc... I've fixed a few bits on it ph gasket leaking .. The gear lever bracket for the remote had snapped off so I've welded a little bracket up (in the same position) and tapped and bolted it to the casing .
Problem is this : starts ok , on tickover I can put it in forward neutral and reverse then I put it in forward (tied to a pontoon) give it full throttle then when it comes back to tickover it won't go in to neutral or reverse ... It's stuck in f
This is with the remotes off and manually operating everything...
Any ideas ? Many thanks in advance jim
Might be a misadjusted / misaligned shaft, or there is something wrong inside the lower unit.
Gear oil was a good point!
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Richard
Gluing geek since 2007
Opinions and intepretations expressed are solely my own and do not express the views or opinions of my employer
Yes... There is gear oil in it ... Changing it was next on my list ... Didn't look that dirty ...
I didn't try reving it up much while in reverse ... It only sticks in gear after I've revved it up :-/
Thanks Spartacus .. Very informative ... It may be my upper shift linkage ... I just read another post somewhere where a guy said if you take the leg off make sure when it goes back the lower leg must be in reverse and the gear selector must also ... I have a feeling this may not have been the case ... I shall be investigating tomorrow :-) thanks for your help jim
Not sure about the not wanting to shift when revved up, but in general the 20/25/28/30hp twin cylinder Yamahas can suffer from a damaged upper gear linkage.
The gear change shaft runs horizontally under the tray between the tray and the leg and has a lever (part number 38 in link below) fixed onto it which operates the vertical shift rod running down the leg to the gearbox. This lever has a pin pressed into with an interference fit it which and can become bent or loose. The damage normally occurs by trying to undo the long brass nut connecting the vertical shaft to the gearbox - if this nut is seized then the twisting motion on the vertical shaft damages the pin / lever. This leads to sloppy gear changes and the engine not wanting to come in and out of gear. The only way to fix this is to lift the powerhead off the leg - actually only a ten minute job - and then lift the tray off which will reveal the gear linkage which can then be inspected.
I have seen them bodged with a nut and bolt in the past but never really satisfactory - needs to be a new part in my opinion - I used to do a fair few of these with this problem as a Yamaha engineer in the 90's but they aren't as common as they once were, which is a shame as they are a better engine than the twin carb autolube 20D/25N and the 30hp triple, but then I always preferred the older Origin / Enduro engines. I still have an original points ignition 1976 28A in storage, no use for it and no value to it but will still be running long after all the later four strokes with questionable Mercury derived electrics have died!
Phantom 19 thanks for such an in detailed reply ... There is no substitute for experience i shall be working on the engine first thing Friday morning ! As for these engines... I feel such a great simple lightweight design has been ditched which is such a shame ... I rely on a boat every day to get to land .. (2actually) .. Re to the 28 you have ... If you wanted to part with it I would be very interested :-) thanks for your time . James
So helpful... Thanks so much... At least I'm not shooting in the dark now completely ... Looking forward to getting it stripped down ... Will post the results up . ..... If ur thinking of parting with the old 28a do let me know ;-)
Hey I just noticed ur Yamaha 90 for sale ... I have a 6 m aluminium rib with a 230 yanmar and castoldi 238 jet drive on ... Ribs a bit tatty so I'm splitting the boat up shortly ... Thought a 90 yam would be ideal ... In the meantime good luck selling it and if I sell my stuff may well be chasing you up on that 90 if you still have it... ! ;-)
Sorted the gear problem ... The lower leg must be in reverse and the shift lever also ... Then thread the connecting nut from the upper threaded bar onto the lower connecting stud ... Hey presto f+R no problem ... Thanks so much for all your time and thought ...:-) Jim
Sula
i shall be working on the engine first thing Friday morning ! As for these engines... I feel such a great simple lightweight design has been ditched which is such a shame ... I rely on a boat every day to get to land .. (2actually) .. Re to the 28 you have ... If you wanted to part with it I would be very interested :-) thanks for your time . James
