See full version: Four Stroke
Yamaha offers a full model lineup in four stroke engines from 425ps to 2.5ps that deliver superb fuel economy and cleaner emissions. Outboards of 20ps and higher are equipped with high-performance fuel injection to take that performance to even higher levels. In many models, our advanced technology realizes acceleration performance and a lightweight, compact design. more
The lineups of outboard models offered differ by country or area. Product names, coloring and graphics may also differ. The specifications of outboards shown on this website may be changed or production discontinued without notice.
Always read your owner's manual before using the outboard and be sure to use it properly.
Direct inquiries concerning Yamaha outboards to your country's distributor or local dealership.. more
[links]
Pulled off the exhaust plate - this exposed the exhaust ports in the cylinders. Rotate the flywheel to bring the rings directly into the center of the exhaust valve. Squit them liberally with liquid wrench, PB blaster etc or MUCH better yet. AeroKroil. more
Fashion a chisel-shaped tool out of hardwood. Take that tool and tap, Ok BANG on the rings. Two stroke rings are prevented from spinning in their grooves by pins. That makes them stick easier than those in a 4 stroke. more
Put it all back together and run some de carb through the intake. I forget what its called, but get some. [links]
The rings might be stuck. All carboned up as they say. I had a 1977 OMC 85 with even mo' worser compression and I fixed it.
Hi all. I'm looking to purchase a used 2006 Seaswirl with a 2006 Yamaha 150 four stroke. We don't know a lot about engines but we had the shop do a compression test because we were told it's a "must do" when buying a used engine. the results were:
Does anyone know if those compressions are within a normal range. or if we should be concerned about anything? [links]
Also, does anyone know if it's possible to get an electronic printout from the computer chip in these engines? The shop is saying they aren't able to do that with these engines. I was under the impression that most "newer" engines had that information stored on a chip and it could be printed off (info like hours, rpms, etc)
Comp with a good guage should be 150# on a cheap guage look for consistency all within 5# of each other.Check lower unit for water.See if there is a water/fuel seperator.
Most Force should start easily if it has trouble starting : Be careful.J here
Re: 1997 Force 120hp compression numbers? more
Thanks for the infos and the quick reply!Definately going to test in the water.I may have found an awesome deal if this boat is in xcellent condition as the seller stated (original owner) more
Is there a way to check the condition of the lower unit? Like see if oil ans seals are good?
Again I have zero experience with outboards [links]
Re: 1997 Force 120hp compression numbers? more