2001 Yamaha 200 hpdi fuel problem

[jim@miss-em.com]

I am having some kind of fuel flow problem with a twin installation of these engines. I have replaced int & ext filters, replaced everything from the tank to the fuel lines going into the engine cowling. With new filters one or both engines will run for about .5 hour at 3-4000 rpm just fine. Engine will start to cut out and reduce rpm eventually to idle. Fuel bowl under the internal filter stays full. At that point I can stop the boat and idle for a while, it will run fine for a few hundred yards or so. Or, while the engine is cutting out, I can pump the bulb a half dozen times and it will run fine for a couple of miles before needing another pump. This has been going on periodically for over a year. Tank looks fine inside. Check all strainers. Both engines exhibit the problem, not necessarily at the same time... swapped fuel lines at the bulb, problem stays with the engine.The Yamaha dealer is no help. They just scatch their heads. The Yamaha customer service line... WHAT A JOKE.

[Yepblaze]

Sorry I don't have a clue about your exact problem, but...When you say the dealer is no help, that just doesn't sound right.It seems that any qualified shop devoted to that brand should have the techs and tools to diagnose and repair what you describe as a fuel starvation issue.Was it that they just had no free advise, or was it they had the boat and charged for repairs on issues they failed to fix?Either way sounds like it's time to take it back and have it fixed right, or find another shop.

[JB]

Sounds like a plugged up or closed fuel tank vent to me, Jim.Try opening your fuel filler when this happens. If you get a "WHOOSH"" and the engines take off you need to clear or replace the vent.Good luck.

[rodbolt]

hello dude we had and still have a lot of low tech low pressure fuel pump problems. test each low pressure pump or better yet just replace them cause they are due. I try to get people to change the pumps each 3 years or 500 hours. they dont live forever. if it was a restriction between the primer bulb and the gas in the tank you would see the bulb sucked flat. next time it slows down shut it off and drain the vapor seperator. if it does not have about 1 qt of gas in it its low. but from those symtoms I would bet low pressure pumps. as far as the dealer scratching I would change dealers. HPDI fuel systems monitor High pressure fuel the dealer has a gauge to monitor medium pressure pumps and the low pressure pumps are the same diaphram pumps for the past 20 years or so, dont go looking high tech until the basic low tech stuff is tested. good luck and keep postingPS if you wish to know more keep posting

[dskogman]

I had a similar problem that took months to find. It turned out to be the fuel tank check valve being gummed up and not letting full flow thru the line.

[rodbolt]

doug that problem should have taken less than 3 hours. one of the first checks is fuel system vacum at WOT. if it passes its good to go. to many dealers jump all over the high tech and totally forget the low tech good luck and keep posting

[jim@miss-em.com]

UPDATE: When this problem showed the engines only had 100 hrs on them. I have been talking to the installing dealer since Oct 2002. When I replaced all fuel line components up to the bulbs I noticed 1/4" fuel line at the bulbs and into the rigging tube (all wires and cables go through the tube to inside the engine.) This is the soft 1/4" line that, I've been told, is supplied by Yamaha. I can close it off with two fingers. It is so tightly packed in the tube that it won't budge at either end. I talked to a different dealer today and they said that line should be reinforced 3/8" fuel line, at least. Doing anything with the rigging tube looks like a nightmare so I've talked the installing dealer into taking a look at it tomorrow morning. I suspect if they replace the fuel line with 3/8" reinforced the problem will go away.I'll keep you posted..

[vinney]

Yamaha uses 5/16 fuel line inside dia. It is thin but designed to go with the rigging boot on the front of the engine. 3/8 fuel line will not change the problem and the thick wall fuel line will not fit thru the rigging boot. The black hose is oil and the gray hose is gas. You need to have a vacuum check on this engine. There is a pre-delivery form If you install the engine correctly You won't have these problems.

[JB]

I don't think weak fuel pumping or line restriction would allow you to go at cruise for half an hour with twin engines before they starve, Jim.That is a good amount of running and a good bit of fuel, more than the lines and pumps can hold, but it is long enough for vacuum to build up in an unvented tank. . .enough to resist the draw of your fuel pump.Check your tank venting before you waste any more time or money. In Yamaha's defense they are engine wrenches. I think you have a boat (fuel tank) problem.

[jim@miss-em.com]

This is great. I want to thank everyone for the feedback. To address a couple of the points brought up:I tried opening the fuel fill cap during an occurance. No in rush of air and no change in the fouling engine.The grey line(with red stripe) is very soft. If there are any twists in the tube a cable could pinch it off easily. I can pinch it closed with two fingers.Also, when all filters are new is when it works fine for a half hour, I can get about 10 miles out. Sunday it ran fine out to the salmon grounds, I started to move to another area and stbd started to act up. I stopped and switched both fuel lines between the water seperators and fuel bulbs. The problem stayed with the stbd engine.

[rodbolt]

hello Vinney and myself have both given you advice. none of it had anything to do with switching. you must perform a fuel system vacum test as per the tech manual. you say if you pump the primer bulb it runs ok. that tells me the low pressure pumps cannot keep the VST full. if it is a fuel lean out and you continue monkying with it you will find out how expensive power heads are, good luck and keep posting

[JB]

Well, you have eliminated the vent theory. At least that didn't cost you any bux.I defer to the Yammysperts.

[jim@miss-em.com]

UPDATE: The dealer said be there at 9 am and they would have someone look at it. Got there at 8:40 and they said "oops", not this morning maybe this afternoon. So that is it for them.I installed a reinforced 3/8 line outside the rigging tube and jury rigged it through the hole for the tilt cables to the 5/16th fuel line at the internal fuel filter. Bypassed the rigging tube completely, both engines. Took it out in front of the harbor and ran around at 5000rpm/45mph for a while. No problems. That was 28 to 30gph flow rate. Both engines seem fine now. I'll give it a month or two before declaring problem solved.I'm going to see if I can find an electronic vaccum gauge for the instrument panel.Thank you for your comments and suggestions.

[mcginleyc]

I think this is a simple problem that might have been caused in the set up of this engine. Simple things first, hook up a remote fuel tank to eliminate the boat fuel tank factor. This is one of the first things the dealer should have done. I am not a Yamaha expert, but I believe the HPDI has a fuel/water seperator under the cowl. If there is one under the cowl adding a second external fuel/water seperator is not necessary. The more junctions and connections placed in fuel lines increases resistance. If you have the means connect a remote tank to eliminate the problem. Good luck and excellent quality responses people!