Mad EFI mid

[rprinzo]

On the powerhead side the crank is perfectly centered between the studs. The red line in your drawing shows that the CL of the D.S. is 0.009" out of center for a total of 0.018 difference of measurement from the driveshaft CL to the port stud hole and to the starboard stud hole. Yes, you are right, this could be due to the top and bottom surfaces of the midsection not being parallel or a shift in the alignment of the bolt holes. I measured the adapter plate itself to verify it is still square and it is. I got the engine all assembled now and built exactly how Todd said to do it. First trial run will be this Friday.

and what happens if it breaks again and does damage to the powerhead,then your gonna have to eat it. if he said theres nothin wrong with it he should have no problem trading it out for another one. and if hes got a problem with that then that about says it all. hes gonna say its your fault if it breaks again.you shouldnt even run it.

[InjectorService]

As I was reading this thread I was wondering.... this time the driveshaft splines stripped out, but what are the chances the crank would strip rather? What about the extra pressure put on the lower crank bearing?

[WiseCraft]

I've been having a weird vibration after the 15" can swap. Wonder if the driveshaft is rubbing. Guess ill yank the power head.

[25two.stroke]

As I was reading this thread I was wondering.... this time the driveshaft splines stripped out, but what are the chances the crank would strip rather? What about the extra pressure put on the lower crank bearing?

Oh yeah! Obviously cut and resplined stainless is softer than the crank and softer than the hardened splines mercury uses. In a misalignment it breaks at the weakest point. In Chris' shaft the splines were the weakest and it did nothing to the crank. I prefer that. I run his splines to 115 in my mirage and have on numerous other boats. They always hold up and get little to no wear when everything is aligned.

I've seen mercury hardened splines worn halfway through the teeth on bass boats in factory engines that are constantly in and out of the water. In these cases the crank still seems to hold up so I think the crank is even harder than the hardened shaft splines. However, If what I have put together with the 300X breaks, then I'm not sure where the weakest point is. I think below the water pump where the shaft support ends. Or is could be at the weld where it was spliced. I just hope it doesnt break at 120 mph + cause the boat he has it on is capable of 130 mph. Image breaking a driveshaft at that speed!

[WiseCraft]

Oh yeah! Obviously cut and resplined stainless is softer than the crank and softer than the hardened splines mercury uses. In a misalignment it breaks at the weakest point. In Chris' shaft the splines were the weakest and it did nothing to the crank. I prefer that. I run his splines to 115 in my mirage and have on numerous other boats. They always hold up and get little to no wear when everything is aligned.

I've seen mercury hardened splines worn halfway through the teeth on bass boats in factory engines that are constantly in and out of the water. In these cases the crank still seems to hold up so I think the crank is even harder than the hardened shaft splines. However, If what I have put together with the 300X breaks, then I'm not sure where the weakest point is. I think below the water pump where the shaft support ends. Or is could be at the weld where it was spliced. I just hope it doesnt break at 120 mph + cause the boat he has it on is capable of 130 mph. Image breaking a driveshaft at that speed!

Do you recommend cut and respline or cut and weld?

[25two.stroke]

Do you recommend cut and respline or cut and weld?

I always cut and resplined until this. And I still cut and respline all my own stuff. From what I've heard its about 50/50 whether people cut or weld. Really most of the time its personal preference. Some occasions require welding: like mixing two types of engines, powerhead of one and lower off another, or when shafts are skinny in the middle and full diameter at the ends (yamaha, merc 4stroke, evinrude)...if you are trying to do it yourself welding can be a pain in the ass. I've done it. The shafts want to pull as they cool and you end up with a bent shaft.

[rgsauger]

I do not even want to think about hitting a bluegill at 130 miles an hour!

[WiseCraft]

I always cut and resplined until this. And I still cut and respline all my own stuff. From what I've heard its about 50/50 whether people cut or weld. Really most of the time its personal preference. Some occasions require welding: like mixing two types of engines, powerhead of one and lower off another, or when shafts are skinny in the middle and full diameter at the ends (yamaha, merc 4stroke, evinrude)...if you are trying to do it yourself welding can be a pain in the ass. I've done it. The shafts want to pull as they cool and you end up with a bent shaft.

I lost my lower over the weekend and getting a new/used one. I need to have the shaft shorten and I have the option of getting it resplined locally without disassembly. Or take it apart and send the driveshaft to Carabella and cut and weld. Just not sure which option is the best.

[Chaz]

And here I thought I was the guy who got the 1 in a 1,000,000 , needle in the hay-stack stuff to deal with ....

I've read this 10 times to be sure, but no where did Todd say .. put it together .. no matter what breaks .. I'll cover , no problem.

What he said was it looks good. Looking at a picture , from far away and being there in person .. he probably should have said . send it back and I'll look at it if your concerned about it. If it's bad , I'll send you another, if its not , you eat the return shipping.

To be fair, he also asked .. if you checked to see if it was rubbing in the drive shaft tunnel ..??? I haven't seen an answer ... thats where 99% of driveshaft issues originate. I have told him before he should have them checked before they leave the machinist. But then they dont do a mock up on each can ... so where do you draw the line as parts supplier .. and whats the blueprint / builders responsibility. Would people pay an extra $500.00 a copy .. and even then , it really only fit the mock up parts if you splitting hairs.
And if you think that one might have issues .. you should have seen the "first gen, before he bought the company" ...


Yes you are right , the crank is between the two stud holes .. but also to the rear , if you want to be accurate about it.

The drive shaft hole, however is not. Here's the straight as an arrow, true to the world plate. The DS hole is not a carrier bearing, so all it requires is to is clearanced.
And for murkery .. I'd say they hit it pretty good .. I've seem much worse from them ...

And hey ... how bout them two front holes for the 8mm bolts .. 12-13 mm holes ..



Yes the 10 mm side stud holes are bushed .. 14 mm hole for 10 mm stud. As my black racin buddy says .. they wanted to be able to hit the side of the barn wiff a red apple.
Me, I went to great pains to use the studs threaded holes as my pilot .
And the stock location .. most deff not a GPS way point by any means ...

Thats a 1/2" bolt .. with lots of room to spare .. I'll have to ask my friend .. about using a green apple .. might be enough room for a 10 mm stud ..



I rekkon that just leave us with the dowel pins to locate and hole everything in place.

Their's with a mushed gasket ....



Mine .. wiff a 3/8" piece of alum I use as a drift .. for a height model ..



Now if someone is building a breathed on 300x that runs the lower unit in an open tunnel ... north of 120 mph , I'm gonna go out on a limb and say .. there are a few parts that need a slight upgrade, because if not .. this is what ya to look forward to ... just sayin ..

[H2OPERF]

I honestly can't believe your gonna run it if the gear case is loaded, the shaft will work harden above the thrust bearings or possibly in the middle if you shortened it there and snap again, thats crazy, find the issue. With the water pump/shift shaft removed let the GC hang on the bolts and see what the gap looks like...if it wont push up and mate to the mid with out a gap on the mating surfaces by using hand pressure only no reason to run it and trash expensive parts. jmho

[25two.stroke]

So a lot of stuff was said on the phone that was not recorded in our emails. The gist of the email there that I posted was just to show that Todd saw all the same pictures as you all saw and he said he sees nothing wrong. That is all the email was for.

No, the driveshaft is not rubbing anywhere. And oh yeah, I know the parts before Todd were iffy. I would expect, however, that a mid purchased from anyone (unless it was disclosed that it has issues prior to purchase) would be able to bolt up and work as is. Maybe some light adjustment is acceptable: the stuff that can be done with hand tools that any person who puts these together has. But if one bought a mid and paid the price its worth and then it needed welding, milling, or any major repairs I would say thats a problem. Whether it be a used factory mid, new mid, or cut and welded mid. If someone's paying thousands for a can they should get one that is semi straight IMO.

On the phone Todd said, and Craig Collabella said, that welded shafts are far superior and I need to put it back together with the welded shaft and it will be fine. Thats what they told me/us to do and that is what my customer wants to do. I think its wrong. VERY WRONG. But that is what I am being told to do and I am VERY grateful for all of your responses. Every one. They are all helpful and I love you guys. Yall know way more than me and most of you have been doing this longer than I've been alive.

[Dave S]

The dowel pin takes the side load.... not the bolts.....0018 is a bad side load on the lower bearings... a 2 peace shaft will be more forgiving.........pushin' 120 anyones best.....

[Chaz]

There is little more add ... lets try a different way .. (I can be long winded)

May-sur-in stufff ...

Stud edge to D.S. edge . Both are close as possible to blocks lower deck. (point of origin) Pretty accurate ...

Screw a stud in the block , let it go thru an adapter plate that offeres no support ( other than to maybe touch on one side and skew it off on an angle)

Then try to measure 6" away from origin ( both stud and DS have slop) and you will get bogus readings. You would need to bridge the stud and shaft to hold them both still and straight. Before even think about measuring. At least in my world ..

The easiest, best, most country boy method I know has already been shown. I sliding drive shaft. Two locating spots in the lower, the crank splines make three. As you can see .. two places can have slight misalignment and a shaft will still go thru, three or more and it has to be straight in order for the shaft to move freely.

Trying to raise a lower unit .. (maybe with the studs out) and start the shaft in a blind area , raise it straight .. to see if it seats on the dowels .. is one step worse. Second to that would be trying to lower a heavy azz powerhead gently over the shaft until it seats. You might feel some stiction as a misaligned shaft is bowed into place. But overall either way the shaft / crank alignment is out of clear sight.

Friday was the big day ... no report .. ???

Gear mesh paint , grease pattern , Machinist dye .. all would provide a "running pattern" within a minute .. running on the hose.

Pointing a misguided finger ... and leaving it hanging is not good

On the other hand ....

I know people think I'm a little rough on Mecurarely's , pricing, machine work ... parts quality and consistency . How would you like to find this jewel in your 300x ..

[25two.stroke]

There is little more add ... lets try a different way .. (I can be long winded)

May-sur-in stufff ...

Stud edge to D.S. edge . Both are close as possible to blocks lower deck. (point of origin) Pretty accurate ...

Screw a stud in the block , let it go thru an adapter plate that offeres no support ( other than to maybe touch on one side and skew it off on an angle)

Then try to measure 6" away from origin ( both stud and DS have slop) and you will get bogus readings. You would need to bridge the stud and shaft to hold them both still and straight. Before even think about measuring. At least in my world ..

The easiest, best, most country boy method I know has already been shown. I sliding drive shaft. Two locating spots in the lower, the crank splines make three. As you can see .. two places can have slight misalignment and a shaft will still go thru, three or more and it has to be straight in order for the shaft to move freely.

Trying to raise a lower unit .. (maybe with the studs out) and start the shaft in a blind area , raise it straight .. to see if it seats on the dowels .. is one step worse. Second to that would be trying to lower a heavy azz powerhead gently over the shaft until it seats. You might feel some stiction as a misaligned shaft is bowed into place. But overall either way the shaft / crank alignment is out of clear sight.

Friday was the big day ... no report .. ???

Gear mesh paint , grease pattern , Machinist dye .. all would provide a "running pattern" within a minute .. running on the hose.

Pointing a misguided finger ... and leaving it hanging is not good

On the other hand ....

I know people think I'm a little rough on Mecurarely's , pricing, machine work ... parts quality and consistency . How would you like to find this jewel in your 300x ..

I've seen rods like that too. Many poptimax have them in it.
Friday he did not run, it was blowing 25+ our new trial date is Monday the 22nd. Definitely will have pics and info that day.

[Chaz]

Friday he did not run, it was blowing 25+ our new trial date is Monday the 22nd. Definitely will have pics and info that day.

I have a saying ... nothing is a mistake, until it leaves my door unmentioned.

Just ask anyone who has been thru the "better man program" (IE has worked for me)

A little less than a week is what you have to be sure if what you put out your door is correct or not. Has had all "problem areas dealt with.
Just slapping something together, and then having a news crew assembled to cover the potential problem's or catastrophic failure .. doesn't shift the responsibility to anyone other than the guy in charge of the quality of the build.

I've built plenty of 6 second 200 mph chassis in my day. A complete rolling chassis came with a brand new brake kit ... sitting in the drivers seat. Yes I would run the brake line thru the chassis, flare the ends. make a master cylinder mount, etc. But the hard parts were not mounted. The new owner signed that he was aware that this was a kit car .. that needed to be fully assembled.

I've mentioned "other" problem areas, results of ignoring them. Shown video's of the correct way to check alignment ,, etc.
There is a reason that the 300xs adapter plate uses all short studs, half up and half down. They knew they had an issue. That was their way of correcting it, and I hate to admit it but they did a good job.
Putting together a 130 mph boat with the older 6 long, 4 short stud arrangement and not dealing with the underlying issues ... well brother, you already seen it once. How do I know ... I seen it too ..