Yamaha 225, ignition problem?

[Millmaker]

Hello!<br />Started up my 91 yamaha 225 BETO(thats the model type in Norway), runs great on idle for a while. Did start the engine on shore. When i throttle up works fine to,but after a while it almost died when throttle,but came alright again. same problem again and again. runs good on idle.<br />Suddenly a flame came out of the lower carb,happened twice.<br />Could it be ignition problems or what?<br />The motor has a TPS(throttle pos. sender?), could it be something with that one?<br />Any help would make me happy!

 

[vidar]

Re: Yamaha 225, ignition problem?

i think you have a fuel related problem...check that your fuel pump workes right..try to squeese the fuelbulb on the line when you try to to apply throttle..

 

[Millmaker]

Re: Yamaha 225, ignition problem?

Ok, maybe youre right. See you too are from Norway, good to see more of us!<br />I havent got any bulb on it, got a separate el. fuel pump though. But seems to get too much fuel if that one is running all the time, im not sure.<br />Is there any easy way to check the fuel pumps on my motor? It also have a prime starter, looks like a fuel pump, but with 2 solenoids on it.

 

[vidar]

Re: Yamaha 225, ignition problem?

i bypassed the puls fuelpump on motor and just used the electric pump....take off fuelline on carb t see that fuel reach carb w some pressure...then drain carbs to see that you got clean fuel...then check timing w stroobelight...if way off you can have shered flywheel pin...the tps contols timing point (not advansing) w throttling up but this only gives poor performance not unwilling to accelrate froooom idle... is this in gear or in neutral??

 

[Millmaker]

Re: Yamaha 225, ignition problem?

This happenes in gear and neutral. but not all the time,it can run good for a while too.<br />Do you have any idea what i should see if i use a strobelight to check the timing? Any numbers coming up or what? I have one of these strobes,but i am not sure what to read. And if it is wrong, then what do i do?<br />Thx!

 

[rodbolt]

Re: Yamaha 225, ignition problem?

hello<br /> if you have not done it then replace all the fuel pump diaprhams. clean the carbs they are most likly due. the flame coming from a carb on a two stroke indicates that the fuel mix in the crankcase is lean and it may indicate a bad reed set, the fuel is only supposed to go in one direction. thats why two strokes dont have to have flame arrestors. the reed is supposed to stop it. the TPS on that motor failed sometimes due to weak tension on the wiper arm. I dont have the specs for the 91 model in front of me but warm idle should be somewhere about 6*ATDC and wot abot 22*BTDC. all the timing in between is computer controlled. the TPS is rather pricy but the backfire is almost always due to a lean condition. <br />good luck and keep posting