Im also having timing problems with my 470 merc.

Hey all got a merc 470 that runs ok but has some timing issue also.Using a timing light the engine will not run at the factory timing marks. Check HB timing marks to tbc and the mark on the money so HB has not slip. Its alway 10 degrees off so if a set the timing to run good at idle and starts up good it has no power on take off, and if i set the timing to run good on take off with is advance the dist, its hard to start cause to much timing. New point , condenser ,rotor , wire ,plugs. Has anyone ever had to replace ther dist on a 470 cause of this problem

Re: Im also having timing problems with my 470 merc.

You should be setting your timing at 4? BTDC at idle rpm. Then check your advance and see if it's working, and going to specs (25-33? depending on distributor).

What model, serial number, or year is your 470? Which distributor do you have?

Re: Im also having timing problems with my 470 merc.

It is a 82 hammond and i believe delco dist . It just wont run at 4 degree 10 the closet i can get witout it dieing out. And even at 10 it starts idiles good but not at wot it spits and sputters till i move dist while im running the boat. This is my third boat with a 470 so i know engine pretty good but this is strang to me. Dist clean on the inside the advance is working good no hang ups and on the light it shows it advancing.

Re: Im also having timing problems with my 470 merc.

Does it idle too slow as you get the idle close to where it should be? If so, speed up the idle until you have both the proper rpm and timing. May also take some mixture adjustment as well to get it to idle properly.

Why are you trying to adjust the timing, what got you to this point? Was it always this way or start suddenly? Boat new to you?
Is the compression ok? No water in the fuel or anything like that?
Plug wires all in the right place?

Sorry, their's just no 'one answer cures all' for your problem.

Re: Im also having timing problems with my 470 merc.

Have had the boat for two years and yes always had this problem just delt with it untill it starting getting worse. Double check everything fireing order points wire ect. The carb super clean and idile screws are set at 1 1/2 turns out. when i try to put timing at 4 the engine just dies wont even run, chang it back to around 10 starts runs good. Its like my hole timing rang is off by 10 or 15 degree if possible. And like i was saying i check my timing mark on HB with tdc on #1 cylinder and all is good. So like i was saying hav had a few 470 but never this problem .

Re: Im also having timing problems with my 470 merc.

And like i was saying i check my timing mark on HB with tdc on #1 cylinder

Click to expand...

Not sure what you mean by "timing mark on HB with tdc on #1 cylinder". You CAN NOT check the timing without the engine running.

With the engine running, you hook up your timing light to #1 plug wire and look at the timing marks, then slowly turn the distributor till the mark on the crankshaft pulley gets to 4? BTDC. You may have to adjust the rpm up a bit and adjust the mixture. 1 1/2 turns of the screws are only the preliminary adjustment, not final.

Re: Im also having timing problems with my 470 merc.

I did replace my dizzy with a mallory, but not sure i needed to. I found a lifter that wasnt doing much. When i was dealing with mine i found i would set the dwell and shut down then start up recheck and the dwell had changed. It seemed like it was all over the place and could not get it down to 4 degrees either. It also only ran at like 12. I replaced the dizzy but also dealt with the lifter and adjusted some rockers (changeing pushrods) and now it holds idle at 4. I am not saying it was the dizzy. I am almost tempted to put the old one back in to see what happens but i think the lobes can get worn and mess you up. The new dizzy was a little pricey but the oem (which i would have bought if i had deep pockets) was like double that. Does your dwell stay in the same place all the time. Dont let my post side track you from Dons advice though. He probably forgot more than i know.

Re: Im also having timing problems with my 470 merc.

just saying i check HB for timing mark with #1 cylinder at tdc so i know HB hasnt slip. Sorry about that Don. Even if i can get to run at 4 degree at idle it wont pull itself out of the water witout backfireing and spitting. Its like you hav to hav two timing points, one for idile and start and hav to move dist to have top end horse power. But thats why it has a dist with a advance , go figure. thanks Don im gona go work on it and double check a few things.

Re: Im also having timing problems with my 470 merc.

Sounds like the advance is seized up partially advanced. Happens sometimes in cars that sit and I wouldn't put it past a marine environment.

If the advance moves, replace the points with a quality set. Your points could be bouncing from too large a gap or improper spring tension. Advancing the timing allows the effects of erratic ignition to be lessened.... Dropped a cheapo HEI in an old Chevy pickup once, and the timing was so irratic, it would not run with less than about 20* and had zero power because the timing varied by about 15*.

Re: Im also having timing problems with my 470 merc.

Ok just got of the lake and with a little tunning got the 470 to run good at 4 degree timming idle screws 1 1/2 turns. Still stumbells mid thottel. Thinking power circuit in carbs no working right cause I can double pump the throttle and runs right throw the stumble to wot. Next step checking power valve. Thinks its been the hole problem all this time anyway. Thanks everyone