merc 350, won't accelerate

[tsutter]

Hey all:<br /><br />I recently replaced the impeller on a 69 Merc 350 (see "merc 350 problem"). I got the LU back on after the change, the gears seemed to work fine, and I got a good strong telltale stream after I put the muffs on and tested the cooling system. Next step was to take her out to the bay and check her out.<br /><br />That's what I did today. Got her started. Idled OK. But when I put it into forward, it seemed like it went into gear, but did not accelerate. Not only that, once in forward, it wouldn't stay running - it would just bog out and quit. When I put it in reverse, it shifts (somewhat noisily), but it reverses well and doesn't seem to bog down. BTW, the telltale was working well. Any ideas as to what may be going on?<br /><br />Thanks in advance.

 

[greasemonkeyozi]

Re: merc 350, won't accelerate

Aw man, thats a good one. My first guess is a fuel/electrical problem, but since it worked fine before, and it only started having this problem when you changed the impeller, I dunno. I dont think the L/U would do this. I think it may just be a coinsidence that something went wrong with the motor the same time you did your L/U impeller.<br /> (1) make sure your getting spark to all plugs. (2) check for any sighns of a fuel leak on fuel lines. Add some screw tight hose clamps to all fuel line ends to seal them up good if not done so yet. (3) Purchase you a can of mercury power tune, spray some in each carborator while motors running with muffs on to temporary clean those things out, you may have a fuel carboration problem. <br /> (4) Make sure your carborator jets are set right. Take your idler screws on each carb, tighten them all the way clockwise, be careful not to tighten them, just snuggem, then rotate counterclockwise 2 full rotations. Now your carborators are set to a good start.<br /> (5) If you have a manual, check your timing.<br /> If any of these things dont check out, and you dont have a manual to check your timing, Email me at www.greasemonkeyozi.com and I will give you some big help on fixing your motor if your interested.

 

[BRIAN03]

Re: merc 350, won't accelerate

Sound like your tripping the shift interupter switch. The shift shaft wasnt in full forward when you put the drive on. Or you bent some thing when installing drive. Shift the drive into forward (if out of the water move the prop so the shifter locks up). Then move the shifter to full throtle. Engine not running. Look at the shift interupter switch it shouldnt be atavactiving the switch.

 

[tsutter]

Re: merc 350, won't accelerate

Thanks guys for the replies:<br /><br />Brian, where is the shift interruptor switch? Does my motor have one (69 Merc 350)? I noticed also when I was putting the LU back on the other day that the shift shaft was bent very very slightly. Could this be part of the problem?<br /><br />One more thing: If you remember from my last series of posts (see "merc 350 problem") that I was concerned originally about cylinder scoring, etc... w/o adequate cooling. I checked the compression of the top cylinder (120psi after 4 turns of the key), but I could not check the bottom cylinder because the bottom cowl is in the way. I still haven't tried the compression on the bottom cylinder yet, but am going to today. TMD told me that the compression tester should fit to check the bottom cylinder so I'm gonna have to fiddle with this a bit.<br /><br />HOpe you all have a great Sunday!

 

[BRIAN03]

Re: merc 350, won't accelerate

Hey man I thought it was a Mercruiser 350 not a 35 hp mercury. Sorry.