Who do you guys recommend to rebuild a set of 300X motors or is it straight forward enough to handle myself? I'm very capable in the shop but since I haven't done THESE motors didn't know if there were tricks to the trade that I'd miss or if "X" is able to massage them a little and keep reliability, I have three that I'd like to rebuild before summer.

I don't mind shipping them off but I'd rather do it as long as it's not a monumental job or there are a lot of tricks you need to know. I'd rather do it so I control the schedule and the parts that go in them but I also know it's hard to beat a man at his trade. If I do it myself where do you get all the parts necessary, I'm sure someone online offers them cheaper than the full retail that all the shops around here want to charge. I assume I'd be replacing pistons, rings, bearings, and gaskets but should rods be done as well or anything else I'm forgetting? Anyone got a ballpark on what I should be looking at total cost per motor, parts and labor and how much of that's labor?

Several of the reed cages have corners that are burnt (started impacting idle) so will be replacing those as well. Is it best to go back factory or does someone make a better part that doesn't have the rubber gasket that's so easy to damage?

TIA

MLB75,
I have rebuilt a set in the past and did all the work but the long block. I had a friend that is at TNT do that for me. We replaced everything but the rods. We did not have any damage on the cylinder walls so they just gave them a quick hone.
I have heard good things about Fullers in the NE. They have worked on a bunch of them. Not sure how many factory Mercury parts are available anymore. If you use the factory read cages they are very expensive.
We also changed one crankshaft too. I would recommend sending out all the injectors, rebuild and service fuel pumps, replace oil bleed lines, also check bleed valves, reeds, thermostats. You should also make sure they use new head bolts for proper torque. Mercury calls for new ones. Same with rod bolts. May also want to replace needle bearings.

How many hours on the motors? Regarding tweaks IMO I would leave them stock. Especially if you have the higher compression heads. Maybe a little clean up on the porting and balance the motor but that is it.
If you want to see I had build thread on here from my old boat with a bunch of pics.

You testing the elasticity of the brake hose? LOL

What do Porshe's, Lamborghini's and Skater trailers have in common?
https://www.screamandfly.com/attachm...9&d=1518743785

red disc calipers ;-)

NP, trailer is looking good!! Finally ran our tank yesterday for first time since you installed our filters and it ran great, thanks again. It was also the first time we ran it since Dale raised the motors 1/2" but didn't have the opportunity to let it rip, hot wife drove from Benicia to Oakland Estuary in dead flat water but she wasn't comfortable driving above 80ish. I drove back, after picking up some friends, but the water didn't cooperate plus we had a full boat. The water pressure at 85-90mph is now at 15-19psi. Absolutely LOVE our boat.

Housten, we have paint!
 

https://www.screamandfly.com/attachm...6&d=1519507215
https://www.screamandfly.com/attachm...7&d=1519507235
https://www.screamandfly.com/attachm...8&d=1519507265
https://www.screamandfly.com/attachm...9&d=1519507289

I sure hope I'm not in charge of cleaning that paint booth when you are done........

Hey we can post again😎
 

^^^^ sweet ride - surprised it hasn't sold but warm weather is coming.....Great pics

Have the paint booth all cleaned up and trailer back on it's wheels .............

https://www.screamandfly.com/showthr...Project/page16