Timing mark 90 degrees out - 70 mercruiser 165

[LDO6490]

Acquired my boat from my fathers friend who passed on recently. Original owner of a 1970 Starfire 190, with Mercruiser 165. Boat is like new and he kept it garaged and used in Lake Powell, AZ. He was a mechanic and rebuilt the engine in 2009. He took it out and put 8 hrs on it, the it never went out again since he fell ill. I have it now and have changed all rubber on the stern unit (bellows, seals, water pump, etc. New shift cable. I rebuilt the carb but really didn't need to because dad's friend had obviously done it. Regardless,, runs like a champ with carb dialed in and cables all adjusted. Oh yes, new oil, filter. New trim cylinders because old ones were shot. adjusted points gap and dwell, no problem.

OK, enough background, here is the problem. Checked timing and it's appx. 90 degrees off. Checked wire order, and they are correct. Tried to move timing mark where it should be (turning the distributor) and of course that is a no go. It's too far out. I have it set by ear and the engine runs great, BUT, I'm annoyed I get the timing exact since the mark if off or there is something I have set up wrong that I don't know. I know in a car you can have the distributor 180, but then it sputters and bangs and you know right away it is 180. The merc purrs, but only bad indication is that timing mark.

Any suggestions?

 

[achris]

Re: Timing mark 90 degrees out - 70 mercruiser 165

Sounds like the rubber in the harmonic balance is shot and the outer of the balance has 'slipped' around... Remove the balancer and put a new one on. And I know that's really easy to say, but not so easy to do because of the front engine mount....

 

[mike165]

Re: Timing mark 90 degrees out - 70 mercruiser 165

Had the same problem,pulled mine last winter to fix an oil leak in the timing case I did not see the HB had two marks 90deg apart one was a well defined mark ( the wrong one ) the other was like a scratch (the right one)!!!!

 

[LDO6490]

Re: Timing mark 90 degrees out - 70 mercruiser 165

Thanks guys. That's what I suspected. HB is NLA, but think I found a used one that hopefully doesn't have the same problem.

I'm trying to think how I can support the engine to remove the front engine mount so I can make the switch. Anyone had any experience with that? Thanks!

 

[achris]

Re: Timing mark 90 degrees out - 70 mercruiser 165

Piece of timber across the gunwales and a chain block/length of rope on the front lifting eye...

Chris......

 

[Don S]

Re: Timing mark 90 degrees out - 70 mercruiser 165

It's also possible that it's an automotive balancer and just has the mark in the wrong place. If it looks to be in good shape, why not just remark it? All you need is an inexpensive piston stop and some spare time and you can have a new dead on mark on that balancer.

 

[LDO6490]

Re: Timing mark 90 degrees out - 70 mercruiser 165

Awesome advice. HB looks OK (Entire engine and bilge spotless so hard to tell). Got a piston stop on order. Will find TDC and mark new timing mark on HB as Plan A. Plan B to replace if it shifts on the rubber.

Thanks guys!

 

[smokeonthewater]

Re: Timing mark 90 degrees out - 70 mercruiser 165

another possibility is that either there is no key in the crank or that it is sheared. ..... personally, I'd say that don hit the mark and if the rubber doesn't look swollen or torn, I'd just find tdc and put a nice bright paint line on it..... done deal.

 

[LDO6490]

Re: Timing mark 90 degrees out - 70 mercruiser 165

For the record...
Found TDC and remarked the HB. 4 months later, the outer ring of the HB started rubbing on the timing chain cover. Removed the HB and it was slipping on the rubber. Found a new old stock Mercury HB on ebay that was the exact part number match. Replaced and all is now well. Should've checked the HB closer. Motor mount, pulleys, etc. in the way made it easy to quick look and declare it was OK when it really wasn't. Glad I caught it before it messed up my timing chain cover.