44 merc reedcage pin hole fix???

[vislaguy]

I have 2 blocks with reedcage alinement pin hole busted out.has anyone had those little holes welded then redrilled a bit deeper??? . I know this is fairly common, so how has others delt with this.thanks mike

[vislaguy]

belts

also, are there aftermarket timing belts for the 4cyl mercs and I heard there is a kevlar version available thru mercury, does anyone know about this to??? thanks mike

[pops67g]

Repair a reed cage?

Unless these are reed cages that have had many hours spent on hogging them out for better flow, why not replace them altogether? These aren't particularly rare parts, so get some more.

[vislaguy]

block pins

its the holes in the block in the webbing between the cylinders.I'm trying to save good blocks this is the only thing wrong with them.

[brian]

drill it.

Just drill deeper and go one size up. This works well, if it is really bad... new blocks.

[ANZANI-QUINCY FREAK]

Block Side Reed Block Hole Busting Out

Having those block side reed block holes busting out is indicative of reed blocks vibrating within the crankcase block (the case gets a shine to it in the reed block area) generally because of loosened fit and sometimes due to the crankshaft not being true anymore and in some cases too much crank end play (crankshaft bouncing) affecting the reed blocks causing eventual block failure.

Some clues to look at is the ribbing of the inner reed block's labrinth seal in the brass or aluminum reed blocks. If the features show contact or flattening or in the case of the older smooth bore brass reed blocks, there is some scoring present, it can be a crankshaft condition/wobble or similarly vibrating reed blocks. Some bolt and loctite the reed blocks in.

Some spray or brush the outside of the block with neoprene to make the fit real tight to prevent vibrations. The key is looking at your crankcase marks and the inner bore of the reed block. They will tell the story as to why your ovaling or breaking those reed block, block side locator holes.

I have seen them break out the into the cylinder liners and destroy the engines innards, so its prudent to pay attention to what you see when exploring the problem.

[trapper]

wow you do know what your talking about. bent crant will do it every time.

[trapper]

wow you do know what your talking about. bent crank will do it every time.

[vislaguy]

neoprene

ok you lost me with the neoprene on the outside of the block. what does that mean.I'm having the the blocks welded and drilled deeper right now ,also I may deck the block and have my machinist line bore to tighten things up .the front plate reed bolt holes were also worn so I am having him drill them out and rebush them with a harder bushing so theres no slop in the bolt hole.I will run these motors next year and see what happens I would like to really know if these are a long term fix or just a bandaid,we will see.If all ele's fails I hit the junk yards for some more blocks .thanks mike

[ANZANI-QUINCY FREAK]

Examination and Observation of What You See Is The Key

I have run stock outboards since the 1960s graduating from what I could afford to the next level ending up with half a dozen 20H, 30Hs and 55Hs before they stopped running stock around here by 1982. During that period I overhauled my and other's engines and observed and noted each engine in terms of what it's internal appearance was before doing the rebuild/refurbishing. Only in a couple of occassions was there any block side reed block locator dowel pin hole problems where a slight wobble of ovaling of the holes took place over a long term created concern. In those 2 cases the hole was drilled deeper, a longer pin was made and it was tapped in and epoxied to make a tight fit again all the way to the top between the 2 cylinders. The smooth bore (crankbore) reed cages showed mild scoring, so it was obvious that the crank was involved but also to the supports, its bearings were looked at as being possible culprits. In one case it was a crank that longer ran true. In another case it was the bottom bearing coming apart slowly. In the one case the crank was changed out and in the other the bearings but bearings and seals in all cases and the scored reed block(s) got changed out anyway with overbores etc.

Saw one engine, a 30H that was the club's class C dog, where the reed blocks fit was so loose you could see where the reed block retaining bolt held the block tight to one side, the locator pin was ovaled and gas leakage could be detected over 90% of the cir***ference of the reedblock. The crankcase showed a "shine" to it showing a vibration was present. The ribbed labrinth seal of those brass reed blocks (not the originals,they were smooth bore)showed excessive wear on one side from being pulled toward the crankcase locking bolt. This was a classic leakage situation between crankcase sections, so that is why it ran like a dog. In that case the reed cages were replaced with tighterones but they were a bit loose too so the outside of the reed cages were neoprene coated to attain the gas seal tightness between the crankcase inner wall and the reed block outer wall and when seated, it went in stiff and tight. That engine ran better right away, no more intercrankcase leakage.

Crankshaft endplay - When Merc makes a recommendation of crankshaft endplay, they mean what they say be it a stocker or a modified. Everything anyone here set up was about a loose .013 inches endplay using a feeler gauge between the crankshaft and bearing (top & bottom) doing it just like a Merc service manual illustrates. Some people however really slop it good (and some seem proud of having excess endplay for some reasons that escape me) with excessive endplays exceeding .025 and even more thinking the looser the better to the point where side swiping the tops of the reed stops happens from the crank being able now bounce around and vibrate and that is where ovaling the dowl pin holes and in case breaking the hole right out between the 2 cylinders occurrs dumping metal right into the spinning innards of the engine block while its spinning/running making a real mess with worst case scenarious where reed stops get bent over, broken off and the engine's innards become schredded junk!

How about finding a 600-4 connecting rod was weighing in at 170 grams while all the rest were between 138 to 145 grams. Sure the engine will run but un-index balanced with as much as a 25 gram difference does setup a long term vibration/balance problem that slowly causes long term problems.

Also knowing when to quit racing a broken vibrating prop can do similar damage to the innards of an engine. Ever see an engine running with 2 of 3 ears long enough to vibrate the crankshaft into its reed blocks with them loosing their labrinth seals as a result? It did not take long and the motor became a dog until torn down to find out why and those innards told that story. Leakage between crankcase sections due to reed block bore damage was evident. Out of balance props setting up a crankshaft vibration will accomplish the same thing over a longer period of time.

Using an entirely wrong prop for your application can set up sever cavitation that sets up surges in engine power and with those surges, vibrations occurr that can destroy an engine from the crankshaft boucing up and down pounding out locator pins. There was a Merc dealer up north servicing a local aboriginal trappers community with Merc 402s at the time that created a pile of wrecks (blocks) piled more than 10 feet across 6 feet high and it was attributed to the dealer purposely selling the wrong prop with the engine for the application the engine(s) were to serve causing severe cavitations blowing out their reed block locator dowl pin holes without exception blowing each block! He was no longer a dealer a short time later!

When you mentioned that going to a salvage operation to get more Mercury blocks given what was happening is more than a good notion, that is why I have a dozen banked here to make choices when things look weird and when they do there is a power loss usually evident as a result. Before spending a lot of money on any engine for racing, do the disassembly and a good study (a forensic post mortem) in terms of what it was doing before piling money into it as the same problems may not go away, meaning throwing money at it without knowing what was going on its throwing money at it without resolving the issues that got you there in the first place!

[Smitty]

Good, John. For situations in which the fit of the reedblock in the crankcase bore is just a little loose, you can lap the mating surfaces of the block/crankcase split. Find a very flat surface (I use the top of an old cast-iron table saw which was machined flat), tape some 220 wet-or-dry sandpaper to it, wet the paper slightly with WD-40, and lap in the parts with a figure-8 motion. Don't overdo it. Finish the job with 400 paper.

Also, you could maybe repair a sloppy locating pin hole with a hard bushing. Or, you could drill and tap the hole, and screw in an aluminum or bronze bolt (with Loctite). Cut off the excess, hand-grind it flush, and drill a new hole. The problem with welding anything is that it can create stresses that distort machined surfaces.

Merc rods get out-of-round at the big end. I have had the local auto machine shops re-size them by skim-grinding the two mating surfaces, bolting and torqueing the cap on, and regrinding the inside diameter. Since these are case-hardened surfaces, you can't grind off more than a few thousandths, but this is usually enough to restore the rods.