2004 Yanaha 200 HPDI

[Rod M]

I've had this 2004 2120 w/ Yamaha 200 HPDI since Sept 2019. The engine has been trouble free until this spring. It will start and idle and run at very low RPMs but won't run at higher RPMs. I have changed the water separator/fuel filter (actually changed the whole thing to a stainless steel unit), 2 other fuel filters on the engine, and the inline filter for the Garmin fuel flow sensor. No change. Any ideas what else to look for?

 

[Fischer Flyer]

Hello Rod,

FYI - you likely already know this: HPDI's have a safety feature to avoid over-revving; they need to be in gear to go over 1200 rpm. When flushing my engines on the trailer I will remove the props and carefully put them in gear to rev to 2500-3000 rpm or so to help them warm up. I use a tub for supplying cooling water as opposed to muffs.

Secondly: the VST filter screen should be cleaned or changed every 100 hours or so. Otherwise your higher end rpm will be restricted. It doesn't sound like you opened up the VST yet which may be a 90 minute job with practice and proper parts on hand.

Thanks!

 

[Rod M]

I've been testing the engine on the water, so that's not the problem. I'll study up on the VST.

 

[BradH]

Clean/change the VST filter in the tank. Get a new o-ring gasket as the old one is hard to get back in.

Also clean the oxygen sensor and dogbone. It helps with the idle.

How are your fuel lines? Make sure they're not deteriorating or collapsing.

 

[Rod M]

I attached a 5 gal fuel tank to bypass the existing fuel system and it didn't make any difference. Have the filter and I-ring gasket on order. If that doesn't fix it I guess it will have to come out of the water and go to a mechanic.

 

[Fischer Flyer]

Hello Rod,

I suggest you check the operation of your neutral safety switch to see if it may play a role in your limited RPM.



Thanks!

 

[channel islands John]

Fuel injectors? If the boat sat for a period of time they get clogged up from the ethanol in the gas... or they may just be old. Swap those.

 

[jzeno186]

I would also check the spark plugs

 

[Rod M]

I run non ethanol gas, and put new plugs in while I was changing filters. I'll check the neutral safety switch.

 

[channel islands John]

I'm still voting for injectors

 

[capecodparker2320]

What rpm are you able to achieve? The first year I had my 2002 200 hpdi, my boat ran fine. Toward the end of the first season, I thought I noticed that outboard did not run as well as earlier in the season. The second year I had outboard serviced at the beginning of the season which included the vst service and all filters including the hp filter. First time out thereafter, engine only achieved about 3500 rpm. Injectors and HP pump had to be serviced. Since that time Ive had no further problems. Knock on wood.

 

[jzeno186]

VST filter and low pressure fuel pumps if you think it is fuel related

 

[markman03]

Unbolt the engine from your transom and let it sink to the bottom. HPDI’s are filter whore’s. Once the problems start they don’t stop.

 

[gman1001]

Hello Rod,

I suggest you check the operation of your neutral safety switch to see if it may play a role in your limited RPM.



Thanks!

Definitely check this. Tons of lists about this on THT. Many from me. Switch is in the starboard side of engine and is prone to fail.

 

[Fishaddict]

Friend of mine had neutral switch $30 change after about $3000 repairs to injectors and valve train by Yamaha dealer. See if you can check a computer on your engine for codes.

 

[buzzard]

I can almost guarantee that it’s the vst filters I had the same problem with mine last year it was running good then wham all of a sudden I couldn’t get it past 1200 rpm’s so I haul the boat and dug into the VST change the filters and I was back up and running in a day good luck

 

[TreyParker]

I had a similar issue last year. It ended up being the small oil pump behind the reserve oil tank (under the deck). It wasn’t supplying the main oil reservoir (under the cowling) with enough oil. It would fill the small main tank slowly and would trip the motor to limit rpms. I tried a lot of options before my mechanic changed this pump.

 

[Rod M]

So, I messed with the neutral safety switch. Put it in reverse and it bent the metal tab backwards. Took it off and bent it back. Checked it with an ohm meter and it works. Didn't make any difference in how it runs. Tore into the VST and put in new filter. Started fine and I revved it to high idle. When I idled it back down it died. Now it won't start. Doesn't fire at all. The manual says to release the fuel pressure before working on the VST, but there wasn't any pressure in the system. Bad fuel pump maybe?

 

[Cman60]

How about have a certified Yamaha mechanic look at it? Seems like you’ve made quite the effort to fix on your own. At a certain point I throw in the towel. Your tenacity is quite impressive.

 

[Fischer Flyer]

So, I messed with the neutral safety switch. Put it in reverse and it bent the metal tab backwards. Took it off and bent it back. Checked it with an ohm meter and it works. Didn't make any difference in how it runs. Tore into the VST and put in new filter. Started fine and I revved it to high idle. When I idled it back down it died. Now it won't start. Doesn't fire at all. The manual says to release the fuel pressure before working on the VST, but there wasn't any pressure in the system. Bad fuel pump maybe?

Good morning Rod,
Thank you for your update! BTW-was the filter in the VST dirty? When I bought my used Parker 4 years ago the previous owner advised me to Always pump the primer bulb firmly before starting to avoid damaging the low pressure pumps. Your low pressure pumps may be weak; if they are the issue your engine may fire if you pump the primer bulb while cranking.

Also, check fuses and electric fuel pump operation.

Thanks!