Long story short I have a early 80s Mariner that I installed a brand new 86-87 Yamaha powerhead, flywheel, and stator plate.
now I am unsure how to set the fully advance timing. I am thinking it needs to be 24 degrees before TDC. My timing pointer is lined up to show accurately tdc marked on...
I have a 86 Mariner 25hp (Yamaha) recently rebuilt, honed, and re ringed. Compression is around 120 on both. Rebuilt the carb. New coil pack and cdi unit. New plugs also. I checked and set the timing at 25 degrees. Also played around a few degrees both ways. Pumping primer bulb does nothing...
purchased a used coil and now the motor accelerates up to 3800 and slowly climbs to 4800. However I noticed a small fuel leak around the upper crank seal near the fly wheel. Could this be causing the unusual performance ?
also the lighter color plug was top and the darker plug was bottom. Could...
TDC does line up with the mark on the flywheel. I have tripped checked the timing and adjusted a few degrees each way with no change. Haven’t checked with a timing light. But I did disconnect the throttle linkage to the carb and rotated the stator manually. The rpms did increase to ~1500-2000 by...
Motor will not exceed 3k rpm when under load. The last lake test the rpms started around 3k but slowly climbed to ~4100. Once I throttled down it would never exceed 3k again. My theory is the performance degraded once the motor warmed up.
Compression is 120 on both cylinders. Starts 1-2 pulls...
Found a new old stock 86-87 Yamaha engine. I plan to use in my 1980 mariner 25ml. Starting the swap swap over and notice the fly isn’t fitting right. Looks like the Yamaha crank is slightly larger in diameter.
Top photo is the new block. Second is the current mariner block.
Can someone...
I currently have a Mariner 25m 695 307037. Long story short I have a few seized head bolts. Now I am looking for a replacement block or powerhead.
Came across a Yamaha 30ae 689 on eBay. My question is would the flywheel, stator plate, and lower unit be compatible with the 30hp Yamaha?
This is a new to new boat. 14ft skiff with a 1985/86ish Mariner 25hp. It’s a made in Japan model. My first outing the motor would not exceed 3000ish RPMs. Took it home cleaned the carb, fuel pump, new plugs. Second test run I had full power and ran perfect. 3rd run the boat ran great for about...