New here and looking for some advice, basket case 1986 yamaha 200etxj

[Those guys]

Ok guys so here it is my brother and I bought a 23' well craft last summer with a 1986 etxj 200 hp outboard the guy was forward and told us it run rough and could start it and keep it running if he kept toggling the choke switch but it ran rough and kept coughing and sputtering, we thought bad gas and dirty carbs, got it home and cleaned and rebuilt all carbs set to factory spec fuel air screws, new gas lines, gas, gas filters, and plugs, no help in the situation same problems as well as overheating on muffs in a barrel and on the trailer backed in the water, checked electrical bad stator replaced stator and pulser, reset timing another go throug on the carbs, Also new impella when changing the impella there was what looked like a new one in it appon further inspection found pieces of an old impella in the tube up to the motor as well as in the water jackets pulled all covers and heads acid bath to remove scaling and all chambers cleaned new thermostats an gaskets as well as the rubber grommets were the pickup tube and water pump come together now we have good water flow from the indicator but still overheats in a matter of mins on muffs. Now when I refer to overheating the alarm sounds and we shut down ASAP, with new stator and pulser runs better no more coughing or sputtering but still can't get to run perfict, any advice on setting carbs? Vacumme sync seams to be the response but can find anyone who does that in our area and not sure how that could even be done on these carbs, we have synced the throttle linkage as stated in the service book as well as put new plugs in again first set did not look bad but did it anyway, as far as overheating goes what could it possible be? Completely lost in that aspect, this is the short version of our problems we have had a hard time diagnosing problems because there have been several missing parts and pieces along the way but I am pretty confident all is there now, also compression in all cylinders is 113-115 psi, and I fought to mention the fuel pumps were also rebuilt with new diagrams and gaskets, and all vaccume, oil and fuel lines have been replaced as well
Any advice would be great

[boats.net]

It will overheat running on muffs, need to put it in water to test water pump. Probably need to check thermostats and pressure control valve.

[Those guys]

Thermostats r brand new even though the old ones tested out ok, what is the pressure control valve and were is it?

[99yam40]

PRV relieves water over pressure at high RPMs from pump, if it sticks open it will cause over heat at low RPM because block will not fill up as it dumps too much water

[Those guys]

Thanks guys makes sense parts have been ordered, any advice on the carbs we have them in the ball park but can't seam to get them right

[99yam40]

They say if the carbs are all clean, the factory service manual settings should make it run properly with the +- spec

[Those guys]

That's were we started with all air and fuel screws and with the throttle linkage synced and it would not start with minor adjustment we have it running and will idle but not well like I said were in the ball park but just can't seam to get it dialed in,

[boats.net]

It will have to be in water to properly adjust carbs, can't do it running on muffs.

[Those guys]

That's the plan going to go pull the pressure control valve see if there is any rubber bits in there and try it again in the water if it's a obvious blockage in there if not wait for the new one and try it all again thanks for the input I'll keep you posted

[99yam40]

If it will not start and run at factory specs then you have some problems still.
Have you checked to see what the timing is at idle and higher RPM?

If compression, spark, and timing are all good then you are left with fuel issues. Test what you can with the proper equipment to make sure ohms and voltages, etc. are in spec

[Those guys]

Well guys some good news I guess I pulled the Prv and it was not even there only the spring no valve or anything but that's what we have been dealing with the whole time we have been working on this motor guess that's what we get for buying someone else's headach go thought they knew what they were doing, but I'm sure the overheating issue is now solved and can move on to getting the carbs in line hopefully be in the water soon!!

Thanks again for the advice guys really helped I didn't even know about the valve

[99yam40]

Hopefully it is not lost inside the motor,
Strange that someone would remove it but leave the spring

[Those guys]

Im thinking that that might have been all the bits of rubber we found int he water chambers and stats, either way all cleaned up again and waitin on the new one

[Those guys]

Hey guys got the parts in today put them
In and took it to the water, no more overheating at all good water pressure out the indicator, but still no progress on the carbs, good gas and plugs everything set back to factory settings according to the Manuel what now?