v-6 dt 150 problem

[Solarman]

dt150, running issues

Lifetime, it sounds like you could have a problem with spark on those two cylinders, that might indicate the pulse coil for those two cylinders may be bad. If you have good spark on those plugs, then it is going to be fuel related.
So check the spark on those two cylinders related to those carbs, and let us know what you find. Good luck.
Bill Con, reed valves can cause problems but there would be back pressure blowing back out of the carbs where the reed valves are not seating.

[BillCon]

Normally yes Solarman that is true I, agree, but I, had a split reed pedal on #1 cylinder of a yamaha 115 and it never show anything at idle, chased that problem for 3 months monkeying around with the carbs and electrical, happened only running above 3000 rpms, it would start missing, went away at low speed, I, found it with a cable inspection camera, but most likely this is a fuel supply related issue.

[lifetime62]

I took the carbs apart on cleaned them ,they were all white and chalky , cleaned them all up and reinstalled them , put it in the test tank and run it did good to about 5000 rpm's and them it was like it lost fuel , thought it was tank , put a small 6 gal. tank on and did the same thing , I had to pump the bulb back up , running it and when it started to act up press the bulb and it would pick back up , it is losing pressure , I ordered the fuel pump kits , going to try it and see

[lifetime62]

I thought about it , what is the normal operating rpms on this motor , I figure on this boat 18"3' fiberglass v hull, have a jack plate on it , I should be able to reach what 5500rpms and about 55 to 57 mph ,

[Solarman]

Should look at check valves inside both pumps before ordering kits. If check valves are broken the only way to replace is buying the complete pump. They do not come with the repair kits. Why buy kits if pump is no good? The check valves make the pump work, push diaphragm in & out.

Good luck. Let us know how it goes.

[lifetime62]

I checked both check valves good , looks chalky inside so cleaning them and should know Friday if it has cured problem we see
cross fingers

[Solarman]

dt150, running issues.

You have two pumps, and 2 check valves in each pump.
The check valves are the small clear discs in the lower section. Hope you noticed you have two pumps.
What type of tank are you running this motor in at 5000RPMs? Are you using a test prop?
Keep us posted.

[lifetime62]

oh yes I checked both pumps and they were good , I back the boat trailer and all into the tank ,have a buddy that has a marine dealership , running my prop

[lifetime62]

solarman you were so right , i saw where the clear plastic check valves were and they were cracked and i checked around and you can't get the replacement part , i had remembered that the mercury 150 had a fuel pump and so i asked for one checked it was exact size but i hole was too small , got my solder gun and made just a hair bigger , put it in and worked there , went ahead and put new kit in while there and put it back together , took it to the test tank and once i cranked it had to adjust settings again , and boy did it go then , so much that it moved the trailer to the side , thanks

[Solarman]

Glad to help. You said mercury has small discs like that. Are you able to buy them from Mercury? I know you took off an old pump, but many here need those discs, and Suzuki doesn't offer, it would be good if we could find a source to buy them if we need to.
Again, glad your motor is working, and happy boating.

[lifetime62]

i will get the part number of the kit and post it

[lifetime62]

guy I have the fix
mercury P/N 21-42909A4
mercury mariner fuel diaphragm pump kit

[Solarman]

Lifetime, do the two discs come in that kit? Do you remember the price for the kit if both discs are in it, if they aren't in it, it won't help much.
Thanx, but do let us know. I may need some of them soon myself?

[lifetime62]

they come with 2 disks in them , i bought them for 12.99 on ebay you have to open the center hole just a tad

[BillCon]

Here is the Suzuki fuel pump rebuild kits that come with the check valves for $20.20 plus shipping
Mikuni Fuel Pump Rebuild Kit D52-21 (DF52-176) (SKU 002-223)