Merc Thunderbolt 200 no forward

[tboregon]

Hi all,

I've read many posts but couldnt find my problem.

My 20 hp motor will not fully engage into forward. Reverse works fine. When I try to engage forward it will spin the prop slowly eventually but its not "engaged" meaning it's not really all the way engaged as I can stop the prop with a shoe (yes I know that is dumb but I could tell it wasn't engaged fully.) There is no linkage problem that I can see the cable controls move fine and dont bind.

With the engine off it wont spin the prop in reverse, but will spin both ways in forward with no sound or clicking. I doubt it is actually engaged.

I'm at a loss any help is very appreciated!!

 

[tboregon]

Re: Merc Thunderbolt 200 no forward

Anyone, anything?

Thanks!

 

[tboregon]

Re: Merc Thunderbolt 200 no forward

Beuller?

 

[lindy46]

Re: Merc Thunderbolt 200 no forward

Did you have the lower unit off for any reason? Or did problem just start on its own? If the L/U was off, possibly the shift rod is not now aligned properly.

 

[tboregon]

Re: Merc Thunderbolt 200 no forward

It just started on its own. I took it out last fall, it worked fine. I started it up "just because" and that is when I noticed the problem. It it stored inside, so weather/freezing shouldnt have been an issue.

Thank you.

 

[lindy46]

Re: Merc Thunderbolt 200 no forward

Maybe shift cable out of adjustment and not going completely into forward. Or linkage in the engine loose. If it's all the way in forward, you should get a clicking sound when you turn the prop clockwise. Try putting it in forward with the shift cable, then disconnect the cable and see if it moves any further forward.

 

[tboregon]

Re: Merc Thunderbolt 200 no forward

Thank you for the reply. Yes I took the cable completely off to make sure it wasnt a cable issue. I can see the manual linkage and it goes into place in all three positions. There is like a three leaf clover connected by a couple gears in the engine compartment one node in the center would be neutral then forward is foward and reverse is reverse. It fully goes into place manually as well as with the cable. I'm assuming it has to be in the lower unit where the problem is, I guess I just don't know what is down there. I wouldnt think its a huge problem but thus far with the mechanics I've brought my motors to, I've had them tell me insane things were wrong (as in my motor was blown...has no compression, the carb is wore out..) and so forth, and all that was wrong was bad gas. Everyone is going to make mistakes on a diag, but thats pretty bad

 

[lindy46]

Re: Merc Thunderbolt 200 no forward

I'm not familiar with your particular motor, but on my Merc 400 there is an adjustable connecting rod between the shift control lever and the upper shift shaft. There is an adjusting nut on this rod which you can loosen to adjust the length of this rod. Not sure if it's the same on your motor, but you could check.

 

[tboregon]

Re: Merc Thunderbolt 200 no forward

Hey thanks a lot, I'll check it out.

I'll post the fix what ever it ends up being.

 

[tboregon]

Re: Merc Thunderbolt 200 no forward

Thanks for the help. It ended up being the internal shift shaft rod bushing was froze up, from what the mech said was probably some salt water/moisture between the aluminum and metal shaft in the bushing. Stuck in there pretty good he had to tap and die it to get it apart.

Anyway, a small local one man shop did me right I'm happy to say