Yamaha VMax 150 issues

[Valmet412S]

I recently purchased a 2004 (i think) 150 Vmax Carb outboard. It has very low hours and looks brand new. Has been sitting a couple years. I cleaned out the clear fuel filter and ran fresh gas into the lines. Runs great on the hose. Got everything hooked up on my 18 foot bass boat. Still have the stock, non-yamaha guages. Loaded everything in the boat and went to the lake yesterday. Fired up the motor and it finally seemed to idle ok after some serious choking.

Prop is only a 21 pitch, which isnt going to give me much speed, but should have been amazing holshot. Not the case. At WOT I couldn't even get on plane. Tach hung right around 2000 rpms. Thinking the carb jets might have been clogged, I pulled the breather off and put my hand over the carbs and choked them individually. This helped, but not enough. Had both my fishing partners sit on the front deck and the boat planed out. I ran it up to 45mph at 4400 rpms, but thats all she would do.

Fished for maybe an hour and attempted to run again. Boat planed out and performed similarly. I slowly started losing rpms after a minute or two and after stopping and restarting, I couldn't get over 1800 rpms. I repeated the hand-choking process to no avail. This time, the alarm went off when I attempted anything over idle. Plenty of oil, motor warm to the touch but not hot. I could turn it off and the alarm would go away, and anything over idle would trip the alarm again. Then anytime I started the motor the alarm would go off.

After I turned it off, it wouldn't start at all and alarm sounded anytime I turned the key to the "on" position without even attempting to start. Got pulled in and loaded up and pulled the top spark plug and I am not getting any fire. On the trailer, the alarm sounds anytime the key is turned to "on". Can anyone tell me what is going on?

 

[Silvertip]

Re: Yamaha VMax 150 issues

Most folks don't seem to have a feel for when an engine is not running on all cylinders which would certainly help diagnosing problems if they did. Obviously the more cylinders an engine has the more subdued a missing cylinder will have but the fact remains, an engine that has lost a cylinder runs rough -- period. The more cylinders that are missing the rougher it runs and the poorer the performance. So -- spark and compression tests are always necessary under those "can't plane" or "can't get over 2000 or 3000, or 4000 rpm" issues. You only pulled one plug and determined it wasn't getting spark. So how did you determine that? Did you pull the other plugs and what did they look like? Reading plugs is like reading a book. They tell a story. Black & sooty = oil fouled. Tan & clean = normal. White = lean, overheat, or water injestion. Reasons for any of these conditions are many so testing is required. If the engine is stone cold and you turn the key on (not starting the engine) and the alarm sounds, there is a problem with the alarm system. Understanding what controls the alarms (over temp, lack of oil, no oil, etc) will help isolating the problem. Knowing what specific alarm (beeping, constant tone, etc) will tell you what part of the system is at fault.

 

[Valmet412S]

Re: Yamaha VMax 150 issues

Tone was constant at key "on" after engine had been sitting for at least an hour. Spark plug was a little wet (gas) and a little dark, if anything, but pretty normal. Idle was smooth when running, not like the engine I had that lost a cylinder. I understand that a weak battery can affect the alarm system, so I am about to go try turning it over with a fully charged battery. I will also check compression just in case. I appreciate the help and will update with more info.

 

[Valmet412S]

Re: Yamaha VMax 150 issues

Compression was 110-112 on all cylinders. I left out some other info. There are two lines on the oil tank in the engine. One is at 2/3 and the other is at 1/3. The oil is at the bottom line, started the day full. So it seems to me that the oil isn't going from one tank to the other. Didn't check for spark just now, its pouring rain. The spark plugs are all dark.

I'm going to fill the engine oil tank and see if that stops the alarm. It came on solid as soon as I turned the key on. The boat hasn't been run in 24 hours, so I know it isn't hot.

 

[cwilt]

Re: Yamaha VMax 150 issues

there is a switch next to the oil tank on the motor which moves oil from the master tank in the boat to the tank on the engine. try to fill the boat oil tank and then move the oil by the switch. i have an (07) 150 v max. the yamaha guages (by light )tell me what the alarm is for, would be a good idea to get them...i had a simular problem when braking in my motor. i doubled the oil for the brake in period and that fouled my plugs. i had to clean them after every outing. i could only get around 4000 rpm's.

 

[cwilt]

Re: Yamaha VMax 150 issues

oh yea, i hate starting my motor for the first time at the begining of a trip, i always have to manually choke it.

 

[SparkieBoat]

Re: Yamaha VMax 150 issues

do a carb job..you may have a lean cylinder

 

[Valmet412S]

Re: Yamaha VMax 150 issues

Will schedule a carb job asap. I assume the alarm is due to low oil in the engine tank? Perhaps an oil pump issue?

 

[99yam40]

Re: Yamaha VMax 150 issues

Yes, probably oil alarm. Low oil or high temp will cause alarm and the RPM to be limited to around 2000.
It is not a good idea to run a motor that is not running properly, as you can hurt pistons and cylinders not to mention cranks and bearings very easily
You need to make sure the transfer system works could be pump ,filter, floats,wiring, etc.

 

[Valmet412S]

Re: Yamaha VMax 150 issues

Alarm was due to engine not getting sufficient oil, clogged oil system. Now engine is not firing. Can the computer system be telling the engine not to run, not realizing oil is now flowing? If so, how to fix?

 

[99yam40]

Re: Yamaha VMax 150 issues

No the low oil level alarm is all you get, and all it does is reduce RPM so you can fill it back up and get back to port and have it fixed before you destroy the motor

 

[Valmet412S]

Re: Yamaha VMax 150 issues

Got it figured out for now. Sounds good running on the hose. Now hopefully the carb job will take care of the other issues. I might pull them off tonight and see how they look.

 

[cwilt]

Re: Yamaha VMax 150 issues

i think the oil alarm only tells you that the oil is low, i don't think it will sound when there is a feeding problem

 

[jrgrady]

Re: Yamaha VMax 150 issues

As far as your oil not transferring from the reserve tank to the main tank, make sure your oil lines aren't pinched anywhere. Then check the in line filters in the oil line. You may have to prime the oil pump on the back of the reserve tank. If all that doesn't work, buy a manual and start the electrical tests for the reserve tank pump. VERY rarely does that pump go bad.

 

[Valmet412S]

Re: Yamaha VMax 150 issues

Pump is functioning fine. There is an in-line filter/valve that was clogged. Ordered one yesterday. Anxious for the rain to stop so I can find out if I need the carbs done!

 

[SparkieBoat]

Re: Yamaha VMax 150 issues

just clean the carbs out..takes about 2-3 hours and a can of carb cleaner to clean out all carbs.