campsers123
16.05.2021 2:54:31
Fuel, expecially the ethonol crap, will go bad in as quickly as a month. Even if you run the engine dry of fuel, there is a bittle bit in the fuel bowls that WILL varnish and clog up jets. more
See full version: Yamaha 25 hp 2 stroke oil mix
Fuel, expecially the ethonol crap, will go bad in as quickly as a month. Even if you run the engine dry of fuel, there is a bittle bit in the fuel bowls that WILL varnish and clog up jets. more
So the noise is NOT happening anymore under the same conditions as before?
Are you using any fuel stabilizer in the fuel. more
I would definitly recommend a stabilizer, you've seen the varnish, even running dry. That or drain the bowls after every outing.
1998 Yamaha 25Hp 2 cylinder 2 stroke oil mix outboard making squeal noise just below lower cowling more
I have an old 1998 Yamaha 2 cylinder that has sat more then it ever has ran. Got it running good and it has plenty of power for a 16 foot Carolina Skiff. Coming in tonight it sounded and felt like at first it was running out of gas dragging down and then surging forward. When I came into the creek and came off plane it was making a squeal right at the base of the engine. Sounded like a dry ball bearing in a electric motor. It idled OK and did not appear to be any load on it. Water was coming out of pee hole and motor was not hot. Motor itself sounded fine. By the time I idled up the creek to home (about 10 minutes) it was not making the noise. Heard it last time I was out. Same thing but then I did not get the maybe tight bearing dragging it down filling. Oil is clean in lower unit and it is free. I took a stethoscope to the engine at fast idle in gear tied up at my pier and all sound smooth. By then I could not hear squeal since it only appears to do it after a few mile run. When I check the upper bearing, its fine. Interesting when I put the probe on the lower section of the advance plate just below flywheel, it sounds rough. However, I am sure the noise is lower.. Could it be water pump. I put motor up about 5 years ago and it has sat all this time. I fogged it good and turned it over with the pull start when ever I walked by but basically has sat on a lift all that time. Could the lower crank bearing have rusted? Any ideas. Thanks
Outboard Spares Response
Hi, If I owned one of these engines I'd be running 50:1 with a decent TCW3 2 stroke engine oil designed for pre-mix. If you're doing a lot of idling and slow trolling you could reduce the ratio a bit if you found you are fouling plugs but honestly I think 50:1 should be fine. Cheers [links]
Is the said ratios needed for large hp 2 strokes . Year 2000 forward . As Most are oil injected anyway . What's the reason for adding oil to the fuel mix if the motor is running fine . No rebuild ect . Dose it save oil being injected .
Shop for Penrite outboard oils & lubricants here . here
25:1 - Mix 200ml of oil per 5ltrs of fuel. This mixture is very rich and is usually recommended for running in brand new two stroke outboards and when running in rebuilt or reconditioned engines. If you have a rebuilt or reconditioned oil injected two stroke outboard (excluding Evinrude ETEC or Mercury Optimax) then you'll just need to add 50:1 to your fuel and let the oil injection system add the rest of the oil to make up the balance to get to 25:1. Most technicians will have their own opinion or view on how long you should run the 25:1 ratio for but, I always recommend between 8 and 10 hours. Unfortunately, you will foul plugs at this ratio and leave a very impressive smoke plume on engine start up but, outboards that have been rebuilt or reconditioned need this extra oil while the piston rings bed into the bores. more
Outboard Spares Response
Hi, This could be a number of issues such as faulty fuel pump, carburetors needing cleaning, ignition issue, etc. I think running 25:1 will not be the issue with this engine. here
Hi guys please assist. I have these two motors however do not know the fuel mixture as some old small motors use to run a 100:1 ratios where as most are 50:1. How will I know. I also do know that fully synthetic has its own mixture like 75:1. here
The Yamaha system is the best ever made. Are you having a problem now?
I'm interested to see what the Yamaha tech has to say. It's nice to hear other opinions. [links]
Mar 25, 2013 #5 2013-03-25T13:12 [links]