Yamaha premix recommendations

[MotorPsycho]

Greetins all. I'm a newcommer to this forum.<br /><br />I've been away from boating for a while and just purchased a Yamaha 2004 2 cycle 25hp motor. Both the owners manual and the website indicate that this engine is designed to be a 100:1 engine. In fact the Yamaha website goes on about this as a point of differentiation between Yamaha's and other motors.<br /><br />I've been reading posts discussing pre mix opinions on this website for the past couple of days. In several of the replies, mention has been made that Yamaha has changed their recommendation to 50:1. I can find no evidence of this either in my 2004 owners manual or on their website. <br /><br />Can anyone point me to a source of information that supports the statement that Yamaha has changed their recommendation?<br /><br />I'll be running my motor for the first time tomorrow. However, during the first 10 hours I'll be following the recommended 25:1 mix. Before the 10 hours are up, I want to get clarification on the ongoing mix.<br /><br />Thanks.

 

[31900]

Re: Yamaha premix recommendations

Hi from Down Under<br />I have gone through the same process with my new Yammy 40. Servicemen will tell you that 50:1 is the go. I contacted Yamaha direct and they stand by their recommended 100:1 as stated in the manual provided that you use the recommended oil. I have just passed the 10 hour break-in period and service and have opted to go to 100:1 with a little extra probably coming out at the middle of 75:1. It runs great on that without any sign of over heating. Its up to you, the amount of extra oil used is of little cost or consequence. Good luck!!

 

[MotorPsycho]

Re: Yamaha premix recommendations

You are right about the cost of oil. I'm interested in a somewhat leaner mix for better performance but mostly for reduced oil fumes.<br /><br />Right now, I'm considering using a top quality oil at around 75:1 and perhaps closer to 50:1 for my first tank of the season.

 

[DJ]

Re: Yamaha premix recommendations

If your real source of concern is fumes/smoke, use synthetic.

 

[MotorPsycho]

Re: Yamaha premix recommendations

Certainly I plan to use synthetic, but my curiousity is still unabated. Is there confirmation that Yamaha has pulled back from 100:1 or is this one of those self perpetuating rumors?<br /><br />My wife who dives with me, mostly on dive boats in the Carribean, tends toward sea sickness. She can control it with drugs, but fumes bother her. If I can safely run leaner than 50:1 I plan to do that when she is in the boat.

 

[31900]

Re: Yamaha premix recommendations

As I said, I contacted Yamaha by email and they are adament that 100:1 is correct. At 75:1 fumes are minimal.

 

[MotorPsycho]

Re: Yamaha premix recommendations

Adam, I'm in the same camp you are. Actually, I wasn't posting primarily to get a concensus opinion on the mix issue. Several people have posted that Yamaha has changed their mind. I can find no evidence of this whatever. I wanted to give people who are passing on statements supposedly from Yamaha to back up what they are passing on with hard evidence. So far, no takers.<br /><br />On a different subject, I started breaking my motor in today. Actually it ran better than expected given the rich oil mix. I was running 25:1 mix of synthetic 2 cycle oil. Even at 25:1 the fumes weren't bad with the synthetic. I'll probably try 75:1 rather than 100:1. I'll admit to being from the old school.

 

[kcole683]

Re: Yamaha premix recommendations

My dad just purchased a 2004 Yamaha 8HP for trolling/kicker duty on his 16 foot boat.<br /><br />We asked the dealer about mix and the tech. said 100:1 is OK but use the Yamaha oil. He stated that he personally would run 50:1 if it was his motor.<br />When asked what to run in break in he said 50:1.<br /><br />Upon reading the manual it says 25:1. I think we will be breaking in at 25:1 and running 50:1 after that.<br />Never had a fume problem with 50:1 here.<br /><br />After these reccommendations I wonder about this guy.

 

[rodbolt]

Re: Yamaha premix recommendations

hello<br /> most small motors of a late model (1985and up,) can be safly run on 100 to 1. OMC put out a bulliten on their 100-1 motors due to internal parts corrosion. if the motor was used weekly 100-1 was fine. if it was used every 2 or 3 months 100-1 had a tendancy to allow the bearing surfaces to rust.my suggestions are use 100 to one and then lightly fog the engine after each weekend of use.but to my knowledge most late model 2 stroke tiny mites use the 100-1 mix. just be aware that at 100-1 its imperitive to do the cooling system maint.<br /> good luck and break it in with yamalube. that way if anything goes wrong your covered

 

[MotorPsycho]

Re: Yamaha premix recommendations

Thanks for the feedback.<br /><br />Near as I can tell, Yamaha has not changed their 100:1 recommendation.<br /><br />However, the manual does recommend running 50:1 after the engine has been sitting for a length of time. Also, based on feedback, it sounds like it is a good idea to run 50:1 right before the engine is put away.<br /><br />Since my engine will be used occasionally, I'll likely be running 50:1 as often as not.

 

[31900]

Re: Yamaha premix recommendations

Probably a good decision. After running my 40 yammy on 75:1 I am very happy with the performance and lack of fumes. I have been using a Shell outboard 2 stroke oil meeting Yammy specifications. Good luck with yours.<br /><br />PS Rodbolt, I no longer believe in monkeys that can fix motors or clean fish. They just eat my bait and drink Fosters