DF150 & DF175 air intake manifold

[RussArran]

Hi, I run a small wildlife tour operation in Scotland. I was out with passengers 2 weeks ago when the port engine (a DF175 K7) failed. After many false starts with diagnosis I found that the flaps on the air intake manifold had disintegrated and caused damage to the inlet valves; the power unit is now in a workshop being stripped to investigate possible piston damage and then (hopefully) rebuilt.

What is concerning me as a professional skipper is the safety of my vessels, crew and passengers - and my hard-earned reputation. I have 2 DF175s with 1,200 hours on each, and a DF150 with about 500 hours.

I've already found references to several other instances of this failure on this forum and elsewhere; I'd like to ask how many other owners of these units have experienced this problem because I need to assess the risks involved - and what has Suzuki's response been when this failure has been raised with them?

If you'd like to email me rather than discuss this in open forum, please do - my details will be in the profile somewhere...

[georgianbaylanding]

I had the same problem with my 2008 DF150's. My port motor went last summer. I started my engines and the port engine quit after 10 seconds of running. I tried restarting it and It would not start. Just turned over, like it had no spark. I had my local mechanic do a quick compression test and found 1 cylinder with no compression. Took it to my Suzuki dealer and found out the valves have broken apart and a piece has hung up a valve which stopped my engine. No damage done to engine, they replaced the manifold. Same problem happened to my starboard motor this spring. My dealer tried to put it through as a manufacture defect for warranty but the extended warranty people denied it!!! SO much for the gimme 6 protection plan. I posted this problem and my current revving up problem last week in this forum but got no response. My dealer said they never had the vavle problem before and they said they checked with Suzuki and they didn't have any service updates either. If your engines have the same problem mine did, get ready for your other one to fail! After they changed mine they are good to go again except for my other issue. I just wish Suzuki would be more upfront and proactive about the intake valve issue so people dont get caught out on the water and have the intake go on them then.

[RussArran]

Many thanks for this! Apologies for late reply but had to go earn a crust on the other side of the UK while my engine is being rebuilt... http://www.suzukioutboardforum.com/i...milies/mad.gif

[RussArran]

...another one bites the dust.

Last Saturday my starboard engine failed; removal of the manifold has again shown that the plastic diverter valves have broken catastrophically during normal operation.

The photo shows what I found when I removed the manifold; the pieces can be seen in the red circles.

[RussArran]

Under investigation

Because I carry fare-paying passengers and have to consider their safety as a priority; and because Suzuki can't see any problem with the design of these units causing engines to fail at sea; I have recently sent 2 reports to the UK Marine Accident Investigation Branch. If any of the forum members would like to contribute to this I will be delighted to pass relevant details over to the investigating officer.