200 Yammie not performing well

[badbass]

After sorting the wiring I had the boat on the water and was highly disapointed at the motors performance now we all know that a 200 on a 17' boat should run like the devil.<br /><br />When I got the motor I done a basic service on the motor wich involved checking the full advance (23 degrees BTDC) and retard (7degrees ATCD) timing, checking the carb links for throttle opening, checking compression on all cylinders (between 115 and 120Psi) replacing spark plugs and lubing all the links.<br /><br />With the service done the boat took about 20 seconds to plane with a 14 1/2 X 19 Stainless steel 3 blade prop and would top out at 4000rpm and felt gutless to say the least.<br /><br />When I got home I pulled all the plugs and noticed that two cylinders were not running at all since the plugs were not even coloured at all. The other four plugs were slightly coloured wich indicated they were running. I took the carbs off and cleaned them real good but there was no dirt in them at all. I have spark on all cylinders.<br /><br />Where else can I do some fault finding?<br /><br />Cheers<br />Rudie

 

[rodbolt]

Re: 200 Yammie not performing well

which two were not firing. <br /> check the fuel pump diaphrams and remove the red plug caps. they unthread, test the caps for 5k ohms resistance. now is were a method of testing spark is nice. the spark must be able to jump a 1/2 to 7/16ths gap. you can make a tester with w strip of copper tacked down the center of a 2' wide or so piece of wood. drive nails 1/2 to 7/16ths of an inch from the copper or steel strip. use some old plug wires or other high tension leads with a solid wire core from the nails to the plug caps. ground the center strip to the engine with a piece of wire and alligator clips. the one I cobbled together in south america last year I held the plug wire ends on the board the correct distance from the strip and nailed the wire to the board. do not let the nail go over 1/2 way through the board. I used a piece of 2x4 cause it was laying there. all your trying to do is observe all 6 at once to see if they all can spark. for testing purposes firing order is irrelavent. all should spark. if one or two dont its time to test the ign system. if all do its time to look at fuel. but do double check the coilprimary wires are on the correct coil terminals most times they are marked with a small white tag

 

[RedRustler]

Re: 200 Yammie not performing well

this may help<br />

 

[badbass]

Re: 200 Yammie not performing well

Some of the caps dont even give a reading at all, and some of them are even on cylinders that are running. Is it possible for the spark to sometimes jump far enough to ignite and maybe on the second time miss a beat. I am quite sure that on a 6 cylinder motor it would sometimes be hard to detect when it skips a beat or two.<br /><br />I will replace them with new ones tomorrow but do I need to get the geniune stuff from yamaha or can I get automotive plug caps since no one carries stock in this place and will need to order from somewhere else.<br /><br />Once I have the new plug caps on the coil wires I will report back

 

[rodbolt]

Re: 200 Yammie not performing well

hello<br /> unfortunatly its mostly a yamaha cap. it has a 5k ohm resistor built into the cap. if you have no readings it can cause a problem. may not be all the problems you have but its a starting point. if a fuel pump diapram is bad it will run ruch at idle and not well on top end.

 

[badbass]

Re: 200 Yammie not performing well

I was lucky enough to find a dealer who had some caps and i replaced them this afternoon and took her out for a ride. WOW this things runs like I have not felt before.<br /><br />Thanks again for the help

 

[Ray Neudecker]

Re: 200 Yammie not performing well

ATA BOY, long hard job to get it going. Enjoy the benefits of all that work.

 

[rodbolt]

Re: 200 Yammie not performing well

see how much fun ya had<br />aint this internet stuff grand. wish we had it when I was a kid