I posted this same question on the DIY section ...no replies in 5 days ...so I brought it home to my Formula Brothers.

Took the Formula out Monday for a nice run up the coast. Seas were 3 ft or less and surprisingly not a lot of boat traffic.

I cruised along about 35 MPH which is about 3000 RPM for my 2: 260 MerCruisers. I decided to blow it out a bit and hammered it. For some strange reason neither engine would run past 4000 RPM.

I am running Alpha 1 drives 1.5 ratio with 19" props. Normally both will spin up close to 5000 RPM at full throttle.

Right now I'm thinking a fuel delivery issue between the tank and the engines. Any thoughts?

I once had the same prob, only mine stopped at 3000rpm... after rebuiling the carb, installing a new fuel pump, and filters, I then had the same issue. It ended up being a small round lego in the pick up tube in the tank!

How a lego got in the tank I haver no idea... I do have 2 boys 5 and 9 at the time... mabye a dare?

I love it!!! Not just the Leggo story...but I got a reply within 10 minutes

I really am thinking about something stopping the pick up in the tank....guess I'll have a look. Hell...it might have 32 years worth of crud on it for all I know.

Sprink check your email.

Well it wasn't the tank pick up...it's clean. Re checked the timing...both engines check out at 32 deg total at 3000 RPM. Checked the throttle linkage on both...both carbs are wide open at full throttle. I don't think it's the tachs because if I trim the drives out too far the RPM picks up to 5000 quickly on either engine while the speed drops. I can mess around with the trim and squeeze 44~46 GPS at 4000 RPM. This is with standard 19" props. This rig has recently seen low 60's at 5200 RPM with 21" stainless. This is a sudden change...I don't know...maybe bad gas i.e. 10% ethanol?

I'm stumped for now.

OK...mystery solved. The last time I had it out I ran for several hours and deeper into the tank than I ever had before. I disconnected the primary line from the tank and found a ceramic filter in the top of the tank riser where a 90 deg elbow is attached at the tank outlet. It has a retainer ring that holds it between a recess in the riser and the base of the fitting.There is also a ball bearing check valve in there. I took the filter out and it was nearly plugged shut!!!

I put it back together with out the ceramic filter and took off to the ramp. On the way over I called a friend that trades stuff on line a lot and asked if he had any 21" props. He had a pair of 21" Mirage Plus RH that had a few nicks in them so we swapped out my 19's and put it in the water.

I noticed an immediate difference on how quickly this old 'bird got up on plane. I headed North up the ICW toward Peanut Island...looked around for traffic and let her rip. She ran past 55 GPS quickly and climbed to 60 with a bit of trim. I pulled the tabs up flat and started pulling the drives up and got this old 255 up on it's toes. At about 64~65 she started a bit of chine walk and settled down for a solid 67 MPH at 5200 RPM.

I slowed down to about 55 at 4800 and ran up to the turning basin. I idled around Peanut Island and headed back downtown West Palm to the ramp. Every thing seemed to work well. I pulled out of the water about 7 PM and gave it a fresh water flush in an inland lake over by Palm Beach Airport. I got home just before 8 PM.

Nice finish to a Tuesday after work. I have to say I am pleased.My 32 year old Formula is back and running strong.

I just am glad I found this problem before I ran these engines too lean and burned a valve or a piston.

You just made my night! 67mph??? Thats crazy! Nice work, I can't even believe it! It seems like that old 255 just keeps surprising you.

67 on gps huh. with 21 pitch mirage's. damn, that is pretty good. makes me wonder what the 23pitch clevers on mine will pull next year. congrats