[Bill C in Dubai]

Would appreciate some advice, recently purchased boat with two Yamaha 100hp engines. Thought to be just under a year old. One engine is perfectly OK and started no problem and runs fine. The other engine struggles to start and with some manipulation we can get it to run and then runs well at high revs.
Both are on the same fuel line. When we come back down to idle the engine, it cuts out and we struggle start again. Boat was lying idle for about 6 months
Any basic suggestions that we are missing here ??

[rodbolt]

hard to help from here without some pictures of the powerhead. the F100 hasnt been in the US market since about 2002.

[Bill C in Dubai]

Have uploaded a photo of the motors, was told these were purchased here during the last year. Would be interesting to check the serial nos against the w/wide distribution. You guys always get the newer products :>)
Looking forward to your help..

[rodbolt]

can you pull the hoods and give us a decent shot of the intake manifold side and the exhast cover side ?

[BruceAML]

It would help if you provided the model number and any other numbers on the data plates.

[island boy]

I have had the same problem with my engine it is a 25hp but sounds like the same problem. I have taken my engine back to the dealer and they drain the carb and put new plugs in it and say it runs fine. When i get it back it still will not run rigt and after a few minuites not at all. let me know if you have had any luck with yours.

[Yamajoe]

i would get the carbs cleaned, could be plugged jets, incorrect float hieght to inlet valve not seating, incorrect idle speed adjustents and so on.

[Bill C in Dubai]

Quickly realised that I had reached my limit of expertise and took it into our local dealer for a general service. He replaced the spark plugs and cleaned carbs and jets. Has run well ever since until today when we had an electrical fire !
Managed to put it fairly rapidly but was rather harrowing experience but I guess that is another job to get done. Not sure if they are still under gurantee or if this type of problem is covered by the gurantee.

Thanks for your helpful comments

[Yamajoe]

Do you know where the fire started i wonder if the rectifer started cooking - that is where a friend of mines started last Dec.

[Bill C in Dubai]

Yamajoe, It seems that the regulator also was burnt in the fire but according to the guy at the dealer it probably stared on one of the relays, find that hard to believe but that is what he says.
At this stage we are looking at around +$1500 repair and with the engine being one month out of a one year warantee and only 150 hours on the engine. Not at all happy....

Did your friend speak to Yamaha about this potential fire hazard. Was his out of guaratee ? Worries me that even after we get this fixed we have another engine that it could go the same way..

Anyone with simlar issues and any insight on how I should handle this with Yamaha. Dealer insists it is O/O/G

Photo attached

[Bill C in Dubai]

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