94 yamaha v-76 250 thermoswitch

[Marylu]

94 yamaha v-76 250 thermoswitch

94 Yamaha v-76 250 saltwater series (txrs) would sometimes missing on cylinders 1 & 3, but pick up when given full throttle, but the condition got worse to point does not pick the cylinders up now at all. We have rebuilt the carbs, replaced water/fuel separator, have spark (not sure how strong it is) and 105 psi compression in all cylinders. We have also checked ohms on most electrical components. Our yamaha sevice manual state the thermoswitch should have continuity when cold and open at a given temp. We check both when cold and have no continuity. Any Ideas? Thanks, MW

 

[redyute]

Re: 94 yamaha v-76 250 thermoswitch

Re: 94 yamaha v-76 250 thermoswitch

there would not be continuity when the switch is cold,but only should have continuity when heated.This test you perform yourself, put the switch in a pan with cold water on a stove and check that there is continuity when the water heats up.

 

[rodbolt]

Re: 94 yamaha v-76 250 thermoswitch

Re: 94 yamaha v-76 250 thermoswitch

hello<br /> did you by chance check the red plug caps. they can do funny things. if this is a carb motor the sensor will affect fuel delivery . if it tells the ECU that the engine is cold the ECU will allow up to 20% more fuel though the enrichner circuits causing # 6 carb to lean out at high speed.<br /> I had one 2 years ago drove me nuts. would sometimes just bog down if running above 4500. after seveal hours of testing I found a t-stat that would stick open and allow the stbd head to overcool then when the ECU opened the enrichment solinoids the #6 (lower stbd side)carb would run out of fuel. Good luck and post more information

 

[regulator express]

Re: 94 yamaha v-76 250 thermoswitch

Re: 94 yamaha v-76 250 thermoswitch

Rod or others, is this what might be happening to mine? 1994 V-76 225 twins. It maxes out only at 4300 rpm...sometimes going to 4600 sporatically if the trim is upped. Also, using more fuel and way more oil than the other side it seems. The other engine goes to 5500 rpm.

 

[rodbolt]

Re: 94 yamaha v-76 250 thermoswitch

Re: 94 yamaha v-76 250 thermoswitch

regulator<br /> carefully test all 3 fuel pumps make sure none of the diaphrams are ruptured.<br /> and check to make sure the clip that connects the oil pump to the throttle link is not broken.<br /> good luck and keep posting

 

[regulator express]

Re: 94 yamaha v-76 250 thermoswitch

Re: 94 yamaha v-76 250 thermoswitch

Rodbolt, how can I easily test my fuel pumps? I don't have the mighty vac thing. I'm told I can test by using the primer bulb somehow...<br />please explain how to test, or how to disassemble for inspection. <br />Thanks again for your generous and knowlegable help.