This CAN'T be good - piston damage

[daveswaves]

Re: This CAN'T be good - piston damage

Sounds good, I run a fuel filter before the pump as well, never had a problem since. All my carbs have the flat top cover on them now as well, Have also switched to an electric fuel pump and pressure regulator, run the carbs at 5.5 psi at WOT, never lean out. I have a 1500 block on the bench right now that was missing the restrictors (every block I have seen is missing them) and I would love to modify this area to eliminate that particular problem. Thanks!

I will post pic's and tools needed. It take about 5 minutes to do .And you dont have to run the #99186 restrictors.

 

[Faztbullet]

Re: This CAN'T be good - piston damage

You just got the block or all the parts to fix? Have you got the 20 reed or 18 reed blocks on crank? The 20 reed give a little more breath to engine along with a good set of carbs (11,14,19,22 series) I got a 150XS factory racing block (no serial #stamped on boss) that needs some sleeves(cheeeep) and a brand new 4 cylinder 650 block if you run into someone that needs one.

 

[daveswaves]

Re: This CAN'T be good - piston damage

You just got the block or all the parts to fix? Have you got the 20 reed or 18 reed blocks on crank? The 20 reed give a little more breath to engine along with a good set of carbs (11,14,19,22 series) I got a 150XS factory racing block (no serial #stamped on boss) that needs some sleeves(cheeeep) and a brand new 4 cylinder 650 block if you run into someone that needs one.

I have all the parts, 20 reed that I have modified by removing the meat from the top part of the reed block where the nut and bolt go through. Running banjo reeds not the stock fat ones. There are a few other little mods, mostly cleaning up the factory flash and balancing the rods and pistons. Whats the deal on the 150xs, I hang out on a bulletin board just for inline merc nuts, somebody will be interested. I assume the sleeves are so bad that you can't bore? Still like to know how you modified the restrictors If you don,t want to advertise the price on this board shoot me a pm. Same for the 650, get me a price and I will pass it on.

 

[Faztbullet]

Re: This CAN'T be good - piston damage

This is a trick a old Merc rep showed me back when they raced. You will need a hammer,5/32 flat tip punch,#60 or .040 drill bit,1/16 drill bit,pinvise and dremel with round cutter. See attached pic's also. 1st picture shows a bleed restrictor. 2nd shows restrictor installed from factory. If a engine ever gets hot(weak impellers) these soften and fall out into cylinder. 3rd pic shows restrictor removed with 1/16 drill bit, make sure you run a piece of stiff wire down port to push out any remains. 4th pic shows result from flat tip punch, hold punch at same angle of hole and peen closed.5th pic shows where dremel was used to camfer edges of hole and new hole drilled with pinvise and #60 bit.

 

[daveswaves]

Re: This CAN'T be good - piston damage

Thanks for the info on the restrictor mod. Makes sense.​

 

[Dave1027]

Re: This CAN'T be good - piston damage

This is a trick a old Merc rep showed me back when they raced. You will need a hammer,5/32 flat tip punch,#60 or .040 drill bit,1/16 drill bit,pinvise and dremel with round cutter. See attached pic's also. 1st picture shows a bleed restrictor. 2nd shows restrictor installed from factory. If a engine ever gets hot(weak impellers) these soften and fall out into cylinder. 3rd pic shows restrictor removed with 1/16 drill bit, make sure you run a piece of stiff wire down port to push out any remains. 4th pic shows result from flat tip punch, hold punch at same angle of hole and peen closed.5th pic shows where dremel was used to camfer edges of hole and new hole drilled with pinvise and #60 bit.

I can see this not holding up. Why not tap in a screw in jet like a carb has?

 

[Faztbullet]

Re: This CAN'T be good - piston damage

Been doing it for years and no problems, and hate for brass jet to back out for some reason and go thru cylinder

 

[Dave1027]

Re: This CAN'T be good - piston damage

Been doing it for years and no problems, and hate for brass jet to back out for some reason and go thru cylinder

Sounds good but in all my years I never once heard of a carb jet backing itself out either.

 

[daveswaves]

Re: This CAN'T be good - piston damage

Sounds good but in all my years I never once heard of a carb jet backing itself out either.

Dave, carb jets are not subject to heat cooling cycles like this area of the block. A brass Jet would eventually come loose. Merc knew this thats why they went with the plastic bleed restrictors (jets). Every single one I have seen is missing the restrictors (jets). My 2 cents.