Tohatsu M50D2 Ignition timing question

[johnrob]

I have a new Tohatsu M50D2 and carrying out the 10 hour service stuff from a genuine Tohatsu service manual.<br /><br />Section 14 - Link Adjustment - specifies that the ignition timing should be set to 24degree BTDC (M30D) at full throttle and 3degrees BTDC with throttle closed. The motor actually has the timing set to 20degrees and 0 degrees respectively.<br /><br />Anyone know which one is correct? I can't believe the engine was set wrong at the factory but you never know? It is running a bit rough which I thought was probably down to fouling caused by the 'extra' oil added during the 10 hour run-in period but it may be the timing?<br /><br />I'm checking the timing against the back edge of a boss on the front half of the crankcase - about 1" back in from the timing marks.

 

[TOHATSU GURU]

Re: Tohatsu M50D2 Ignition timing question

The M50D should be set at 24 degrees BTDC. Refer to the two line drawings in your manual and have faith.

 

[johnrob]

Re: Tohatsu M50D2 Ignition timing question

Thanks Elvin, however....<br /><br />I spoke to Tohatsu UK just before reading your reply (I eventually persuaded a tech to speak to me!) and he told me that the M50D2 should be set to 20 degrees - the M50D is 24degrees. <br /><br />I don't know what the difference is between the two models but I can't belive the timing cvaries that much?

 

[TOHATSU GURU]

Re: Tohatsu M50D2 Ignition timing question

Your correct. The D2 has different length adjustment rods so the spec has changed. I hate it when I'm wrong.

 

[dwestby]

Re: Tohatsu M50D2 Ignition timing question

I also have a M50D2 with another type of problem. Need to get more rpm out of the motor have disconnected the rev limitor and the timeing is at 26 dregess we are running at about 6800 rpm no matter what prop we use . this is on a hydro and use for racing only . Question is there a chip or block in the black box that will not let the motor turn up more rpm or is due to size of the reed opening and the tranfer port size. the more timing I add or take away make little or no difference. More fuel is being blow back out the front case. I have Omc loop charge and have turn up into the 7800 to 8100 rpm with no problems this got me question the black box dennis

 

[Sea Rider]

Re: Tohatsu M50D2 Ignition timing question

I also have a M50D2 with another type of problem. Need to get more rpm out of the motor have disconnected the rev limitor and the timeing is at 26 dregess we are running at about 6800 rpm no matter what prop we use . this is on a hydro and use for racing only . Question is there a chip or block in the black box that will not let the motor turn up more rpm or is due to size of the reed opening and the tranfer port size. the more timing I add or take away make little or no difference. More fuel is being blow back out the front case. I have Omc loop charge and have turn up into the 7800 to 8100 rpm with no problems this got me question the black box dennis

Running at such high rpm will shortly blow the motor, that model should run 5800/6000 at max wot.

Unhappy Boating