Sneeze, Cough, Whatever...

[rodbolt17]

carbs be gravy money.
everytime I open one up with old nasty gas all I smell is cold hard cash .

[99yam40]

was Yamaha the only on to come out with that procedure?
I never heard of doing that flow test before, but that would make since if they had a problem with casting slag causing problems somewhere down the road.

Rodbolt or anyone else, do you have any info for the OP about the amount of force it takes to slide the timing he asked about in post #38?

[pstephens46]

Boscoe
how many times have you actually done that test?

I did it once just to see.

and that was probably 15-18 yrs ago.

I may have done 1 or 2 V carbs since then.

I would think summertime would be best. Flip flops and swim trunks too.

[Jason2tpa]

posting to just bring this question back up since it was not responded to by Rodbolt.

I myself have never even looked at that motor so I cannot say how much force is required to move it, but if the throttle linkage needs to move it along with the carb linkage when you move the throttle , I would not think it would take much force to move the magneto.was it still hooked up to the other linkage at the time you tried to move it?

Yes. The manual did not state to disconnect linkages prior to moving lever.

[99yam40]

then I would unhook it to see what is causing it not to move, so you know what to look at for problems.

before doing that look to see if it moves as it should when moving the throttle control lever.

with everything hooked up I would think the control lever, cable, and all other linkage would have to move to advance that timing lever, so would be difficult or impossible to move with trying from back there

[Jason2tpa]

then I would unhook it to see what is causing it not to move, so you know what to look at for problems.

before doing that look to see if it moves as it should when moving the throttle control lever.

with everything hooked up I would think the control lever, cable, and all other linkage would have to move to advance that timing lever, so would be difficult or impossible to move with trying from back there

I agree. So many times we here on this forum tell newer members to "refer to sm", or "follow your sm", etc. If disconnecting linkages is required prior to manually moving lever, you would think this important step is listed in the sm. However, i do recall I disconnected the cam linkage arm and tried to move magneto lever. I applied the same force to move it and it did not. Which is when i gave up not knowing HOW much force should be applied. So moving the magneto either requires some muscling or moved via controls. Thats what i was hoping someone here would know since the sm does not state.

[Jason2tpa]

And one other thing that came to mind. When the binnacle controls are in neutral position the magneto lever is in retard position. IF moving the magneto lever requires using the controls (therefore NOT muscled manually) and you wanted to have the magneto lever in the advance position, this would mean starting the engine and moving binnacle control into gear. Cut engine. Then you could advance the throttle control lever and this would move magneto lever from retard to advance. Right?

It was always ingrained in me never to shift gears if the crankshaft isn't spinning. Starting the engine to move into gear isn't necessary if you have a 2nd person to spin prop as you move into gear. But let's assume this is a solo project.

And of course all of this back and forth of ideas wouldn't be necessary had the SM stated either the lever needs to be moved via controls or via muscle. Instead it just states, "move magneto lever".

[99yam40]

did you monitor the timing with a timing light with everything hooked up and motor running?
Idle timing, pickup timing, and WOT timing to see if they were were they should be?

Just saw you last post, but do not know how you would check timing without the motor running and using a timing light.

If you want to move the throttle only during testing disconnect the shift cable

[Jason2tpa]

Found this thread from years ago. This member states you should not be able to move magneto lever manually without disconnecting.

[cpostis]

did you monitor the timing with a timing light with everything hooked up and motor running?
Idle timing, pickup timing, and WOT timing to see if they were were they should be?

Just saw you last post, but do not know how you would check timing without the motor running and using a timing light.

If you want to move the throttle only during testing disconnect the shift cable

His service manual under "INSP/ADJ, Control System, Ignition Timing" shows how to check/adjust timing without timing light or motor running using timing marks and dial indicator.

If Jason does not have a remote with "fast warm up" button, it's easy enough to disconnect the shift cable at the motor to get the magneto control arm to move to whatever position he needs like 99Yam says. Otherwise, you may have a problem with your linkage to your magneto (doubtful)

Be aware, running on muffs is different than in the water or in a tank. You have no back pressure in exhaust and your motor will run differently.

Here's a vid of mine just after rebuild. Click on image to open

[IMG]Flushin' by Charles Postis, on Flickr[/IMG]

My two stroke runs about 150rpm higher and sputters occasionally on muffs. In a tank, dose not sputter a bit and holds between 740 and 750 rpm.

[Jason2tpa]

And one other thing that came to mind. When the binnacle controls are in neutral position the magneto lever is in retard position. IF moving the magneto lever requires using the controls (therefore NOT muscled manually) and you wanted to have the magneto lever in the advance position, this would mean starting the engine and moving binnacle control into gear. Cut engine. Then you could advance the throttle control lever and this would move magneto lever from retard to advance. Right?

Wrong. I'll correct myself here. Stopped by the boat earlier to confirm the above. The magneto control level moves between advance and retard when the neutral control button is engaged and throttle moved forward.

So I did a quick ignition timing check in the full advance and retard positions using the timing plate and spec mark for each. Between the timing plate mark and spec mark are about 2 flywheel teeth. So it's not dead-on, but at least it's not way off. I'll have to address this in the future when I can dedicate more time.

Thanks everyone for all the help.

[99yam40]

I still think a timing light is the way to go to see what the timing is when the motor is running. manual gives a way to try and set it close, but check with a light to see for sure what it is firing at

[Jason2tpa]

I still think a timing light is the way to go to see what the timing is when the motor is running. manual gives a way to try and set it close, but check with a light to see for sure what it is firing at

Agreed. On my list of to-do's. Thanks again bud.

[bondobill]

I had a similar issue with my 97 Yamy 200 2 stroke a couple years back.
Check the small hoses that run from the Reed valve body to the block. If your 150 is the same as my 200 there should be 1 hose per carb.
I had to replace those lines cause they wouldn't stay on the check valve nibbles anymore.

My engine coughed, sneezed, at idle something horrible when I had a couple of these lines come loose especially when engine was cold.
Here's a couple photos of where to look.



This one shows the nibble.....center of photo......that the lines supposed to be hooked up to



Probably no help but it might be worth a look.

[Jason2tpa]

Thanks. It's something I'll take a look at.

I believe I've resolved the minute timing issue. I ended up making an adjustment to the cam linkage, which allowed me to back off the idle speed screw a little, which allowed me to turn in the pilot screws. The 3-4 times I've taken out boat since adjustment it has not had the quick drop of rpms at idle. Seems to be consistently idling more smoothly.