Now that the newborn is hear and we are settled in i've started trying to get the PowerCat run enough to break in the rebuilt motors.
The starboard side motor fires right up and runs like a top, considering all the extra oil for break in.
The port motor is another story. Last 2 times i've had it out I can't keep that one running. Runs on the hose if you play with cold start to keep it running. Also while on the lake you can get her started, but you have to play with cold start and keep it advanced even once it settles down. When it runs for a bit i'll put it in gear and it dies.
I've checked the plugs and they don't look bad. It doesn't seem to be a fuel flow issue, bulb is still firm after it dies. My wife took a video on her phone i'll upload later.
Nice looking cat. Once were since shoveling to the end of our driveway I'll get right on it! Live in pa and got 35 inches. My ATV plow can't handle it. Don't have a snow blower any more.
But yea the mercy carbs need attention. I had junk from a dirty tank and water get past the fuel filter. Need to open up the carbs and clean em out. I have played with idle but think a jet is clogged. Thanks for the help!
Dave is right - possibly just needs the float needle links set, but once you have the float chamber top off and before adjusting the links, turn the top upside-down and gently place your finger on the links and see if you can easily mush them down causing the needle to go deeper into the brass needle housing allowing the (2) red links to make contact. If they doe, the carburetor will flood as described.
If it does,...The needle & seat assembly are old - possibly original style that are compromised by ethanol & old age.
If so,...Replace the needle & seat with a Sierra Marine # 18-7057 or 18-7061, depending on what serial number your 1000 is, and whether or not it has the original float chamber tops.
The new needle & seat assembly does not have the neoprene washer to seal the needle - it has an ethanol resistant rubbery point on the needle that seats into a machined hole in the brass fitting.
The difference between the (2) part numbers I posted is they have a different thread for the brass housing in the cast aluminum float chamber top housing.
The 1000 Merc is right in there where Merc changed from using the earlier 7057, and went to using the 7061. I used to think that all old "Tillotson" tops used 7057 and 7061 was for the "Mercarb" tops, but I've found that not to be totally true in the 1960s.
If you remove the brass housing & post a pix by a ruler I can determine which part number is correct for that carburetor top. If the tops are the original, all the 1000, 1000ss, used the 18-7057.
See also the attached pictures.
I don't believe you can simply purchase the rubber washer any more, without purchasing the needle & seat kit.
In a pinch,...I have turned the rubber washer over, but I can't recommend that as a permanent fix.
I recommend purchasing a new needle & seat kit from Sierra Marine.
In fact, I would be putting new needle & seat kits (and floats like Master ed-mc suggests)into all (3) carburetors.
Based on your picture, I see that you have the original fine thread brass housing, so you will want to use the Sierra Marine 18-7057 kit and the Sierra Marine floats 18-7208.
The attached pictures show the difference in threads between the 18-7057 & 18-7061.
So here is a pic of the end of the seat i was trying to describe. The rubber washer i was talking about is PART of the seat. I think Tim rebuilt all the carbs on these two motors but i could be wrong. The gaskets look pretty clean.
Here is another angle of the needle and seat. They look different than the Sierra Marine part.
Oh, what's the best way to get that pin out of the cover? The one that holds the "secondary lever". I used a punch but it seemed pretty stubborn.
Decided to go out and pull the other 2 seats. The middle carb top says "Mercarb" instead of "Tillitson" and has a coarse thread seat! All three are the same with the rubber in the seat and not on the needle point. This is the motor that had 3 carbs from a 900 instead of from a 1000. I guess when he rebuilt it he only had two "tillitson" and one "mercarb" Now i have to order the other part number 18-7061.
Oh well, i'll have an extra 18-7057 for one of my other mercs.
On the carbs, the Mercarb name came in in the 70's no cross flow 90 cu in were done with those as far as I can tell. Be wary of mixing and matching, this cannot be done silly nilly, who knows what previous fellow did. These are sensitive to jetting a set of poor running cylinders effects the pulsing intake/ exhaust. Try to get a matched set, 1000 carbs are easy to come by. Lean high speed mix will toast your motor. If you have 900 carbs on a 1000 it'll be lean, reed stops are higher on the 1000 than the 900 for more air flow. Who knows about the mystery Mercarb.
On the needles and seats, the earlier carbs use the copper gasket to seal the seat to the carb top. Needle should have Viton tip.
The levers limit needle drop and also determine when the needle closes thus setting fuel height in the bowl, this is also critical in obtaining correct fuel air ratio and stabilizing fuel level.
It looks like you have 65 vintage 1000's if cowls are correct. You would have dual points ignition. If you don't know how those are set up that maybe another issue.
I'm pretty sure he just meant that two of the float chamber tops are Mercarb, which are okay to mix-n-match on the Tillotson & WMK carbs, and that all three carburetors are from a '65 900.
And,...Yes he will need (2) 18-7061 needle & seat kits for the Mercarb tops.
Sorry for the confusion. The motor ORIGINALLY (when i bought it, not from factory!) had carbs from a 900. Tim Calms rebuilt both motors and at that time replaced the 3 carbs with carbs from a 1000. You are correct, all six pistons were burned beyond use. The top carb has a Tillitson float chamber top. The middle has a Mercarb top, and the bottom has a Tillitson top.
So currently I'm 99% sure the carbs are from a 1000 and are NOT the ones the last owner put on it and burned up the pistons. At this point this motor is all spare parts since the block, pistons, carbs, and pivot/mount have been replaced with parts from other motors. It ran great until I hooked up the on board tanks that each had about a gallon of water i neglected to remove.
How can I tell the difference between a 900 a 1000 carb?
Looks like you have KC-7A carbs, which should be fine as they are originally for a 93 ci 1100.
The main jet size is the only critical issue, and I am confident that Tim would have installed the correct ones for the 90ci 1000.
I put .071 mains in my 1000 builds, but there were .069 mains listed as standards too.
Am I correct in assuming that the choke butterflies are partially closed in an effort to show the carburetor part number, and that they actually open up completely when left alone???
I'll have a look at the mains, see what they are. What's the trick to getting them out when the carburetor is still on the motor? I unscrewed one of the main jets, but couldn't get it to come out so I screwed it back in the carburetor.
Good eye, I didn't notice the butterflies. If you look at the top center of the picture of all 3 carburetors you will see the electric choke plunger that fits in the solenoid. That was tucked back to get it out of the way and was holding the butterflies closed. They do open completely when that plunger is un-tucked.
"What's the trick to getting them out when the carburetor is still on the motor? I unscrewed one of the main jets, but couldn't get it to come out,.."
Since you were able to get the one main unscrewed, you can get it out of the hole by sticking a round toothpick into the main jet, and then pull it on out. I typically soften the toothpick by 'chewing' on it a bit. It 'sticks' into the main jet better that way.
Once you have it out, you should be able to see the size stamped onto the surface.
If you want to check the other two main jets (since Tim did the work they should all be the same size and unnecessary to confirm), I would be pulling the other two carburetors off to carefully access the main jets. With a bright light and keen eyes, once you have seen what the size stamp looks like on the main jet in hand,...You might be able to look in and see their size stamp without removing them from the carburetors.
I have the tool. common name slotted screw holding driver.
ebay 111881411721. just a small modifying does the trick. put it in a drill spin it and sand it down enough to enter the jet hole. takes about 2 mim. to do. they come in short also.
My new floats and the needle/seat for the Mercarb arrived today. I have the Mercarb top and new float installed, after checking adjustments.
I looked into the jet and could see it's a .069. Did that for both the top and middle carbs, both the same. Not going to bother with the bottom one. Maybe after break-in i'll get some larger jets.
I had a toothpick all chewed and ready to go, but didn't bother taking the jet out. Dave, Thanks for the info on the screw holder. I might get some of those, they look handy.
All three carbs are KC-7A. Once the other two needle/seat sets get here tomorrow i'll get those installed and try running on the hose this weekend, maybe. Should get up to mid-50's this saturday... Can i run them with the cowling supports off? Or should i put them back on first?
And,...If she doesn't want to idle happily,...You may have to open (counter-clockwise) as much as a 1/2 turn +/- in the cold weather.
Do this at 1/8 turn to both carburetors for each idle test, then add more C-Clkwz as needed. Note what it was at originally though as you may want to return to those settings in warmer weather.
OK sorry did not understand it was just the tops. KC1A comes to mind for 1000 variety carb. TC knows what he is doing so if he did carbs then I would imagine it's an unlikely candidate?
I would still do some ignition diligence with the split 3 and 3 the motor runs like crap when one side goes down.
Things could also be fine then not, lots of ignition possibilities to cause your issue.
Just offering other possibilities! As simplistic as they are in theory of operation problems can be confounding.
I had two gotchas when everything looked "OK". One was the firing order on the 6's is not all the same, the 76 cu in Merc are close but different than the 66 cu in.....who knew....took me days and days to stumble on I had wires connected to wrong plugs as I kept checking the same (incorrect) firing order.
I once had a loose carb flange nut, when motor got warm , where gasket was not fully clamped, it became a vacuum leak so motor ran lousy, once cooled the leak closed it ran fine till hot again, boy I went bald figuring out that one.
Anyways always check the basics, I always start with a compression check, and verify reeds are there. If mechanics are good it only leaves fuel or ignition. You are on the right track eliminating possibilities.
At least weather is warming so ya got time to figure it out before the good days arrive.
Thanks for the input guys. I didn't get to do a test run this weekend. Had to work won a honey-do drywall project. I hate dry wall...
But, I did get all three carbs back together. Also have the cowl supports back in place. Emptied and cleaned the dredges out of the portable tanks i have. I'll go get some pure gas this week and hopefully give her a go by this weekend, though it may get cold again this weekend.
So had a warm day of 62℉. Here is a video of the port motor running. I think it's running better. I still can't completely lower the cold start lever. But that could be due to the cold weather? I did not mess with the idle screws on the carbs. The motor never gets warm to the touch. I ran her for a total of 15 minuted or so. Since we are on a well that water from the hose is COLD.
Thanks for the help guys. Let me know what you think.