Spark plugs

[jfed72]

I have a Yamaha 2005 VMAX HPDI VZ225TLRD took her out the other night and she seemed it be running pretty horrid. I am a new to Yahama's just purchased the boat this spring. So I checked the plugs and they look terrible. After doing some research I found the tag on the boat and went and bought the correct plugs. I dont think the plugs that were in it were right. Should I be concerned by how these plugs look? I do run ring free and treat my gas with ethanol treatment.



I also had some gas leakage on my water separator filter so I ordered a new seal and filter.

Thanks for any input!

Joe

[Reata210]

Color looks ok, you want a light brown color. They do not look too rich and none look lean. They look like they were in there way to long by looking at the ground electrodes and center electrodes. When you say correct plug do you mean stock? I would run the correct NGK stock plug. Let us know how it runs after new plugs. If still not correct we can help you troubleshoot

[jethro1]

Those are not the correct plugs for any Yamaha model.

It is anyone's best guess as to what an incorrect spark plug should look like.

[Reata210]

I just went to the E3 site and they don’t make a plug for any 2 stroke Yamaha. Amazing someone would have installed those. Even being the incorrect plug, in reading them the plug burn was good. This bodes well that it did not lean out from too hot a plug.Length could be a different story. Are they the exact same length from the gasket on the plug body to the base of electrode ground as a stock plug?



Did you test the engine before purchase? How many hours on the engine? Just the fact those plugs were installed would lead one to question anything maintenance related that was done, or more than likely not done.

[jfed72]

I did the same. I couldn't match the plug on the E3 site. I bought the plugs that were listed for the motor on a tag thats on the motor. I bought NKG's I never even heard of the E3 spark plugs. I did compare the new plugs to the E3's and the new ones were shorter. I did have a compression test done before I bought it. It had 88 hours on the motor and I talked to the mechanic and he said compression was good and I have the numbers at home. He is a very stand up mechanic that works on HPDI's in 3 states.

I dont think maintenance was ever done on this boat. The trailer was a mess. The rims were rusted to the hubs. Had to replace all the hubs because the drain plugs were rusted in the hub.

Going to take her for a spin tonight and I will report back. I ordered new filters for everything now. Is there anything else I should check since I am doing all the maintenance?

All the feedback is much appreciated.

[Reata210]

I would change all filters before running it again. Surprised the mechanic with, as you stated, good HPDI knowledge that did a compression test did not comment on the E3 plugs, especially being longer. Hope they did not nick the piston crowns. The tolerance there is almost nonexistent. When you indicated you have all new filters coming, are you doing the 10 micron, clear bowl pleated filter, VST and HP? If so, that covers all of them. If it sat very long I would consider dumping all the oil in the main and remote oil tank. The fact E3 plugs that are not even listed for the engine were installed it is anyone’s guess what oil that is. If you are familiar with Yamaha Lube, you can tell by the smell if it is Yamaha Lube but I would get it out. I would also install a new pump/impeller and grease all zerk fittings. There is one behind the prop as well. Some things can wait before running it again but I would change the filters before firing it again.

[Reata210]

Meant to mention, I would also siphon all fuel and start with fresh.

[Charles Prestridge]

I also would not run engine until you send off the injectors for cleaning/calibration.

Good 10 micron fuel filter/water separator, all new filters including the secret ones, and injectors cleaned/calibrated would be a minimum.

Has water pump been changed? Have you checked the low pressure fuel pumps for leaks?

Look at other posts and I think many have changed to "one number" different NGK spark plug on the 225-250 hp HDPI's.

[jfed72]

I think I might have to take it to a shop and have it looked at. I should have been a little more diligent when I bought the boat. I was thinking having a compression test done and low hours was a good thing. Its turning out not to be the case with this motor. It bothers me I bought it from a Marina and none of this was checked. I paided good money for this boat...

I do appreciate the feedback. As you can see I need all the help I can get;-)

[bgibson]

I wouldn't get all upset, most of the suggestions above are going above and beyond. I would just do the regular maintenance and go from there. I'm sure you are jumping to conclusions. Just take one thing at a time, not a big deal.

[Reata210]

I wouldn't get all upset, most of the suggestions above are going above and beyond. I would just do the regular maintenance and go from there. I'm sure you are jumping to conclusions. Just take one thing at a time, not a big deal.

I don’t think anything mentioned is going above and beyond. In fact, not doing what was discussed could very easily ruin his engine. I indicated all filters, plugs and fresh fuel and 2 stroke oil. These are key to a healthy HPDI. At a min these should be done on an engine with no history. Based on the OP’s description of the boat when purchased it sounds like it was neglected.It is a low hour engine and with little money and effort can give him years of great service.All items are key to that.To the OP; if you’re good with a wrench all this can be easily done yourself.If not, take it to a shop to have done.Some guys on the board who live near you could probably give you a good referral.One more addition would be lower unit gear oil change which is easy to do yourself.All you need is the gear oil, pump and two gaskets for the drain and fill holes.Very expensive piece and you want to ensure the gear oil is clean and not contaminated.Once you do what is listed you can be assured your engine is getting fresh clean fuel which HPDI engines are very particular about.Not sure what was meant by “going above and beyond”.

[Chisco]

Have to agree with Reata.....this is a 2005 motor with only 88 hours. It has sat for a significant amount of time. Moreover, the trailer was in bad shape and the incorrect plugs were installed. I would definitely have a complete service done on the motor. I would not run it again until you got all fuel related components replaced.

[jfed72]

Well after getting most of the filters changed ( except mystery filters) and new plugs, cleaned the gas tanks, and remote oil tank. She runs like a beast. Wow what a difference. Been checking the plugs after each use and they are way cleaner than the previous plugs. I bought spare filters for the motor. To be on the safe side should I change these out again after a few weeks of running to make sure the system is clean? Thanks for everyone's input.

[19jag99]

I have a 2005 250 HPDI. I didn't have the issue with a incorrect plug though. I would keep running it if is not giving you no problems. I did a complete filter change, including the (mystery filters), the main thing is clean, clean, fuel. I would replace your paper filter (water separator) once a year. You keep the filters clean, and do routine maintenance it will run fine.

Good Luck.

[Reata210]

Good to hear. Sounds like you have her dialed in.