Wonder what caused the powerhead to go out

What would be weird about 2 and 4 going bad? Are those uncommon cylinders to go? 2 had no compression but spark plug looked normal, 4 had no compression but the plug had little metal dobs metal to it ..

I guess im just curious to see what the cause was im not really familiar with the hpdi if a fuel pump went out that goes to those 2 i guess that would make sense.

#4 is where I would start looking for the problem. When a 2 cycle loses a cylinder from a piston seizing it is pretty normal for it to contaminate a cylinder next to it or across from it.

Sounds similar to what happened to me about a month ago. I was running 5500rpm, then the motor kicked down to 3400rpm. I was able to limp her back to the dock. Found little pieces of metal on the #1 spark plug. I didnt have any compression loss tho. $3k later Im back on the water. My bearing cages failed and broke my rod. Service Marine in Emory was very honest with me.

a lot of these motors fail because folks don't change all the fuel filters on the 100hr service like they are intended.once they start to run without the regular power the damage to the hard parts is sometimes already done.

B.O.A.T.

Break Out Another Thousand

As others have stated you first need to find out what the problem is and second what caused it. rebuilding the power head will solve problem number 1, but will not solve problem number two if cause of failure was not mechanical. Earlier yamaha HPDI's had alot of powerhead problems and even yamaha themselfs could or would not put their finger on exact causes. I have seen numerous of these powerheads and I am a firm believer in the major cause is the effected cylinder was running lean. To solve that problem has much as you possible can, you MUST keep clean fuel going to the cylinders at all times and the only way to do that is by regular maintenance of the 11 filters (actually 3 filters and 8 screens) wich are on the motor itself as well as the 10 micron filter everyone should have installed in their boat. Also inportant is the regular maintenance you should be having done on the fuel injectors themselfs. As far as cost of where your at now expect a powerhead rebuild itself to run anywhere from $3500 to $5000 but do not forget the cost of all the filters and service that should be done on the injectors to run in the neighborhood of another $500 to $1000. Sorry for the long post but don't want you to just get the powerhead rebuilt only to go throught it again in a matter of a few months if not sooner.

Thanks for the info