I need one of them stage III ....




















For a anchor!!!!!

I'll take that bet.

97 hours --opening day of duck season ..running out to spot hear a lot of poping an clanking. motor still run but no power . after hunt drove back to ramp ,5 miles....thought a coil was bad ,only running on 1 cylinder....found out the pin that holds the roller in the rockers came out ,the rocker then pushed the spring down and pop the keepers ,valve drop and slap piston a bunch of time and bent in all most closed postion.....put new heads on an finish out duck season..got lucky that no other damage was done...............45 mudbuddy with carb pretty soon it will be .020 over with the works

who is doing your .020 over work?

I had a stage II Briggs... and the weakest link was the block... to me it is just crap block... internally the motor ran flawlessly... cracked the block and still ran it at 4600RPM spitting oil out the top of the block to get back to the camp.... probably could of kept on running it but would of went throught a quart of oil a day and the rate it was coming out...

If you start with a block that can hold together and build it right these motors will be reliable....

Too many stock blocks are breaking just goes to show that the product you are starting with is the issue not the mods...

I will have my Generac on my boat by next week and I promise you it will catch hell... you think a MM is hard on these motors put it spinning an airboat prop...

Got a call last week about a pin coming out of some hodges rollers and a bent pushrod. Have not heard what other damage was done. The blocks suck, so it don't matter who builds it and there is a good chance you could hear a crack then nothing. I have 22 hard hours on this Generac without having to turn a wrench other than trying differnet intake carb combos. No bolts coming out or breaking and no gaskets leaking. More hard hours to come with hopefuly the same results.

Didn't prodrive use Generac like 5 yrs ago or something?

i'm doing the build . a machine shop is doing the bore. have been running a 45 with carb and iron heads for some time. to many cold wot going to get a wound duck scared my cylinder wall and the next step up is .020 over .and block looks good ,no other problem 110 hours now

if engine does crack .... welded it up ...

Wooooha! Good thing you can weld!

mods are over-rated!

EVT sent me all the parts, and at the end i sent the stage 3 motor back and they sent me a new powerhead from pd .but it still cost me alot .

exactly. lol

well my bad, I stand corrected... da same ones MB used to use. lol

I have a sneakin suspicion they look a lot alike though.... just sayin. lol

naw.......say what stump.......why would u say that

well I'll be damned... deadbird put the picture edit to it and I must say, I'm impressed. Still won't buy none though. lol

My 07' MB45 blew up at around 30 hours, rounded the exhaust lobe on the cam. Had all kinds of cool looking metal pieces coming out of the oil. Al rebuilt it (MB covered the cost), didn't have any motor problems for 100hrs until I sold it last year. Felt like a time bomb to me though.....The new rollers that MB are using are alot more beefy then the old. Installed a set this spring on a Buddies motor, seem to be running ok.

Stage 1 and 2 went fine . The fun started with the evt stage 3 kit. The evt cam broke in two after 2 hours ( One in the drive way one on the water.

Installed a bps cam ran 10 hours had to re-bore 20 over because the boat Dr. did not feel a complete tear down was need to clean out debris.

Got about 20 hours on re bore, got a lean condition and ate a piston.

Still sitting in a box , back to stock, but doing heads and carb soon.


Blow up one and two happened the week before opening weekend.

JD

When you guys run these motors with Stage III's in them are ya'll running them wide open all the time and thats why they are breaking down, what would be the advantages of having the stage III and still running the boat around 4000 RPM's, you would have all the torque you need and load carrying capabilities you need and still be hitting like 33-35 with a load without running the hell out of the motor. Just becuase you have the Stage III doesn't mean you have to run the motor all the time at its full potential, help me out here i am trying to wrap my head around what you guys are talking about when blowing these motors.

My new motor has stage 3 internals but has bone stock heads seam to be doing pretty good!!! HAs a lot of load carrrying and run s plenty fast enough but only turns 4300!!

When you push a big boat like I do , you gain nothing from stage 3 until you hit 4500 rpm and gain only two or 3 mph on my 20x60.



problems with stage 3 are

a) vibration, if any is coming out of the drive train/ prop or if the flywheel is out of balance, it is magnified and shows up as cracked block , or leaking rear seals and crankcase gaskets, and bolts backing out or breaking off also speeds up broken welds on mufflers.

B) cams breaking or running flat lobes due to poor weld jobs, or due to stress caused by roller rockers with too much duration paired high lift cams.


c) too much compression, and lean fuel ratio's


JD[/quote]

So your saying that an unbalanced prop (which would cause extra vibration) can cause a block to crack?

vibration is all about frequency....

any vibration you have can be increased at any point in time if another identical vibration is encountered... aka resonance...

a off balance prop at 5000rpm is bad enough but if the engine itself has its own matching vibration at 5000rpm it gets bad...

chances are you will find resonance several times the trick is not to stay at that RPM...

but the more vibration sources you have the more at risk you are... balance everything you can... cranks/shafts/props/flywheels....

also if anyone can find a engine shop willing to spin balance these little cranks we have pass the word on... most engine shops want $$$$....