merc and top-pinning

[biggerbass]

so been reading up on the merc's problem with top-pinning and seems like it's credible that it is a consistent situation. coming from the high performance stand point of auto racing i totally understand so not a big deal...every motor has it's flaws(in this case it's the pins/pistons and not the motor itself). has anyone used the us1 method of implanting a pin from the top and then welding it shut? testimonies?

i really want a merc motor on my bullet, but want to make sure i don't get stranded on the waters under WOT.

[racerkvn]

I'd venture to say John Marles (US1) top pins more pistons than anybody in the country.

[jaybo]

I agree Marles is the one to do it

[20xdBake]

He will be the one to do my Promax pistons when I get around to takin it apart

[Hydrilla Gear]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 20xdBake &raquo;</TD></TR><TR><TD CLASS="quote">He will be the one to do my Promax pistons when I get around to takin it apart </TD></TR></TABLE>

Chris, the 1st thing you need to take apart is the clasp on that chicks braw in your avatar

[racerkvn]

[20xdBake]

It has only been about a 1/2 hour since I have turned my computer on and I have heard 3 comments about those things

I am goin to start a thread that says "My Aviator"
How many responces do you think I will get?

[racerkvn]

How many is it going to take? We are slow at work today, so I can reply as many times as needed.

[jaybo]

Mark me down for a pair

[biggerbass]

what hours do MOST get with the merc pro motors before a rebuild? this would really help me in finding my boat soonl

are the optimaxs and efis pinned bad like the pro motors too?

[jaybo]

All motors have problem and if you push them to the edge they will all break. My guess if you leave the merc stock you will have plenty of years of service before you have problems. I think most guys that have problems have the limiters removed and are turning some serious r's. If you want speed get a merc if you want dependablity get a yamaha. You have to pay if you wanna go fast

[racerkvn]

My Dad ran an 86 2.4 200 on his 19 foot Bullet to, just guessing, but probably around 3000 hours before "I" blew it up (lost locator pin) 2 years ago. It my have had more than that on it! It literally was on the water 2-3 times a week, every week.

Most Promax's should get 300-500 hours fairly easy, if they don't live at the upper rpm limits all the time. I know of alot of them that had the pin come out of the piston, but I also know of several that hasn't had a single problem, and they have LOTS of hours on them. I think if you take care of your stuff it will take care of you. Any Nikasil'd motors will need to be freshened up every 100-150 hours, depending on leak down percentages.

[20xdBake]

yeah, OK

I can't speak for the 3 liter motors having problems with them, I only owned 1 and it blew because it lost an injector. I think there was a few other problems that motor had that they didn't tell me about because they pulled the break-in history on it and showed that I idled something crazy like 55 hours out of 70 total hours. I was 19 at the time, and they definatley didn't believe that I idled around all the time

Any 2.5 merc with side pins will eventually fail though, it doesn't have to be a Hi-Po motor or run ragged. You put an aluminum piston and a steel pin in some heat and the friction fit isn't so friction anymore Some get lucky running them, but I am not one of those people.

[biggerbass]

do the newer 250 xs have any problems with top-pinning?

[20xdBake]

The man to ask for problems with that engine is Don Weed on the Merc 3 liter board.

[biggerbass]

thx... thought most of the bullet guys would know