need throttle help Black Max 150

[jdizzie]

Well, I'm still having major throttle problems on my Whaler Revenge 20 1987, with a merc black max 150, and quicksilver binnacle mount control box with the trim adjustment on top of the knob.


I brought it to my local outboard guy and he's telling me everything's working mint on land. He wants to splash it this coming Thursday to see what it's like running under load. He's going to run it in the sound on Thursday.

However, when I ran it, (keep in mind I've had this same issue since I bought the Revenge last August), I'm having the following issues :

No throttle response when in forward. I'll have to push it to 3/4 just to get it to move beyond real slow.

The throttle will not stay open, it falls back on me, I have to keep it pinned with my hand and steer with my left.

It won't get up over 4200rpm at WOT, and then if I'm lucky it'll "catch" all the throttle and sponttaneously jump to 5500 rpm (where I believe it should be at WOT)

Top speed is approximately 26 mph via the Sitex and GPS.

The throttle doesn't stick, it seems to shift fine, and it's not utilizing the full power of the motor.


My local guy said I would need to switch to some Gen 2 merc controls or something at absolute worst?

But the motor screams, I know the motor runs well... What Gives?

What dou you guys think I should do?

Any response is greatly appreciated.

Graci,

-J.

 

[jdizzie]

Re: need throttle help Black Max 150

Still need help.....

Bump

 

[gss036]

Re: need throttle help Black Max 150

There should be an adjustment in the binacle mount to tighten the throttle so it stays. ( I will have to look an old one I have sitting in the shop from my 1989 200 HP Merc) There are way to adjust the throttle cable on the port side of the engine. Maybe it is slipping in the track. Might need what is called link and syn to get the adjustment needed to get to full throttle. That would take some knowledge and an OEM manual to do correct.

 

[jdizzie]

Re: need throttle help Black Max 150

So I just got back from the outboard guy and gave him all the info that I acquired. Possibilities included : a spun prop hub, an electronic intermittent motor problem, the throttle cable itself being shot, everything to the cover for the control being on backwards.

He tells me that the throttle cable is stainless steel, it would break before it would bend, and he's 99% sure it's not the issue. He also tells me : "You know kid, It might be your prop..."

OK, so he takes the prop off which is a michigan wheel rapture stainless steel prop ( I believe a 17) ... he pulls it off, and "What's that pencil doing in there?" Pencil????? Sure enough I look into the prop and there's a regular pencil running through there. He says to his buddy : "What do you think, was it cavitating?" I have no idea what cavitation is or why there was a pencil through my propeller but he's putting a different prop on tomorrow (an aluminum one, which I'm not very fond of), and splashing it in the sound.

$125.00 I'm up to, and no repairs made.... ugh.

The saga continues.....

I'll post more info when I get some.

 

[jman72637]

Re: need throttle help Black Max 150

Hey, I don't know much but I know your guy said he's 99% sure about the throttle cables being ok but the problem I was having was very similar and all it cost me for a new set was $42.00. I don't know how old the control box is you are using but if you bought it used it might be smart just to upgrade anyway.

 

[gss036]

Re: need throttle help Black Max 150

I am no expert on props, but a pencil inside the exhaust section would mess with the exhaust flow some, but make it cavitate, I don't think so. If I had to guess somebody dropped it into the case while doing a water pump repair it found its way out the only route available. But at least with the wheel he put on, you will know if that is you problem. Don't let him keep the SS Prop, it worth 5 times the aluminum one.

 

[jdizzie]

Re: need throttle help Black Max 150

Well, we (the outboard guy and myself) splashed the Revenge Saturday with a new Merc Prop (with no pencil) and still had the same problem. Still only getting about 4200 rpm, and the throttle would still fall back at WOT. We get back to the launch, and then..... nothing. No spark, he's saying the stator is shot. I guess there's like a high and low end to the stator, and that's why on land he's not seeing a problem, but I was having all the afore mentioned issues in the water.

So, he's changing the stator on tuesday, My new question is : Can I put a higher amperage stator on this old black max? Would it be better? And.... what do you all think about me buying this aluminum prop? If the prop wasn't the issue, should I go with it anyways? I sort of want to, just because I do not have a spare, and I've learned that it's good to have a spare ANYTHING when it comes to boating.

Thoughts and opinions are greatly welcome as always.


P.S. - I pulled that pencil out of the old prop, the rapture SS, it was jammed right through the side of the prop to the hub. Why it was there?, I'm still not sure.

Regards,

-J.

 

[jdizzie]

Re: need throttle help Black Max 150

Still need replies...

bump.

 

[Chris1956]

Re: need throttle help Black Max 150

There is such a thing as troubleshooting the motor. You start with a compression test, move onto a spark test, and then to the carbs, carb adjustment and link and sync.

From your description, your machanic cannot tell the difference between a spun prop and a bad throttle cable. I think you need a new mechanic.