96 yamaha 225 saltwater series carb syncing?

[Asainz320]

When i bought this motor i was told by the owner that he had just rebuilt the carbs so i had to sync them. Yesterday i took it out for the first time. It started up fine but when i put it in gear it started to bog down and i had to give it throtle to keep it running. When i was able to, i gave it half throtle and it ran fine brought the boat on plane and everything. After like two minutes running at WOT it started to slow down like if it was missing gas. I brought down the throtle to like 1/3 and got to the dock. When i brought it home again it was being a little difficult to start. Can this be a carb syncing problem? The comprecion is 120psi in cold and 110 on all cylinders in hot state. Aslo, is $120 the right price to sync these carbs?
Thank you very much for any help provided.

 

[99yam40]

Re: 96 yamaha 225 saltwater series carb syncing?

I would take some of that $120 and buy a Yamaha manual for your motor and sync it myself.

Sounds like you may have more problems than sync. Check fuel delivery problems with a pressure/vacuum gauge.
May have to look at carbs again, could be trash in jets and passages

 

[rodbolt]

Re: 96 yamaha 225 saltwater series carb syncing?

its among the hardest set to do in the yamaha lineup and MUST be done correctly.
buy the manual and the TPS voltage test harness.
DO buy ONLY the factory manual from yamaha.
most aftermarket manuals tend to get confusing.

 

[Asainz320]

Re: 96 yamaha 225 saltwater series carb syncing?

Today i took it out again and as i was expecting it was doing the same thing. When in idle it shakes a lot, but it seems to go away when i give it throtle, but i still notice there something wrong. It was like if it had air in the gas line. When i brought it home and trimmed the motor down something black was leaking from the prop. Like gas and oil mixed. Could this be a plug miss firing? I took the plugs out and they're all firing a spark but i know this doesnt mean much. What can this be?

 

[rodbolt]

Re: 96 yamaha 225 saltwater series carb syncing?

could be almost anything fuel related.
could be a failing stator.
not knowing who did what I would do the carbs again,replace all 3 lift pumps and test the stator charge coil outputs.
improperly installed, missing or defective orings on the enrichment solinoids will do it.
that black goo is unburned fuel.

 

[Asainz320]

Re: 96 yamaha 225 saltwater series carb syncing?

Hey guys! I got the manual for the engine. After some extensive reading and trouble shooting i found a couple of wrong things. First one of the fuel pumps had a tear in the diaphragm, replaced it. Then found out that two of the plug caps assemblies where bad (didnt have any recistance), replaced those two and two more that had well above 5kohms. Also gave a shot at syncing the carbs. Took it to the lake to try the new changes. I didnt noticed to much of a difference at first. Still same shaking and bad idling as before; but this time when i gave it throtle i felt the difference in pick-up and speed. I was doing well above 50mph, no hesitation, no coughing, nothing. When slowed back down to idle, same shaking and coughing. When i synced the carbs, i made it so that all carbs open and close the same amount at the same time. This is what i dont know if its correct;i started playing with the port side throtle adjustment screw and opened a bit more the port side carbs. Almost all the shaking and coughing went away.
What is the best way to sync the carbs myself, i can't get much information from the manual on this subject. Help is needed! and very apreciated.

 

[99yam40]

Re: 96 yamaha 225 saltwater series carb syncing?

Sounds like the pilot/idle jet/passages still have some plugging maybe.
Rodbolt said that motor is difficult to sync so I hope you took his advice and got the factory manual and followed it step by step.

 

[Asainz320]

Re: 96 yamaha 225 saltwater series carb syncing?

I did listen to you and Rodbolt. Thats how i found many wrong things with the engine. Now, i read on the manual how to sync the carbs and it seems very complicated even with the step by step instructions they provide. I thought it was going to be easier to sync the carbs having that manual but its not. I guess i'll have to take it to a shop after all.

 

[Asainz320]

Re: 96 yamaha 225 saltwater series carb syncing?

Update:
Today i talked to an outboard mechanic and i was told i dont need any special tools for the job. Just a flats head and a philip screw driver will do, thats what he said. Now, i trust you guys (Rodbolt, 99yam40). Is this true? I dont need special tools to sync the carbs? Im planning to go after work and take the carbs home and rebuild them myself to be sure that they're done correctly. Is there a test i can do to see the condition of the reed valves? thanks again for your help guys!

 

[99yam40]

Re: 96 yamaha 225 saltwater series carb syncing?

I an wondering as to if the Yamaha manual said to use any special tools for the syncing. I would not think it would, but I have never done one of those motors before so I can not say one way or the other. As far as I know they need to open at the same time and the same amount to be in sync.
Just make sure all passages and jet are clean to let it run correctly.

 

[Asainz320]

Re: 96 yamaha 225 saltwater series carb syncing?

Thats exactly what im doing now. I took all the carbs off and im doing them myself to be sure they're done correctly. After that im going to try to sync them again.

Now that the carbs are off i can see somewhat the reed valves. Would it be a good idea to crank the motor to see if any pressure from the pistons is coming out through any of them?

 

[Asainz320]

Re: 96 yamaha 225 saltwater series carb syncing?

Something new i found today, two of the pilot screws were in bad shape. Here's a pic so you can see the damage. Could this be one of my problems syncing this engine?