hand starting Volvo penta diesel

[reginaldobaker]

Anyone have tips or experience hand starting (via hand crank) an engine?
Think the starter motor on the old md6b might be going out and I’m curious if the hand crank method is viable.

This model has a decompression lever to be flipped up during hand cranking but I’m still not able to rotate the flywheel/hand crank with this flipped up.

the previous owner mentioned they couldn’t hand crank either, as it was too difficult to rotate.

here is a YouTube clip of someone performing the hand start and it seems quite easy - not sure what I’m missing

 

[ConchyDug]

I'd pop the valve cover off and check to see if the decompression lever is actually doing it's job or if it's broken. While the cover is off I'd check the valve timing(proper timing helps for faster starts).

I guess you already checked the starter wires for corrosion and if the battery passes a load check?

That's a pretty cool engine.

 

[supersailor]

be very careful hand starting a Volvo. A friend of mine broke his arm hand starting one on a San Juan 26.

 

[reginaldobaker]

I’m dealing with an increasingly slow crank, no start issue and agree the batteries are relevant. Got one load tested and it passed but remain skeptical. The hand start has been appealing since it bypasses both the batteries and starter.

The decompression lever seems to behave as expected during electric starting (very fast spinning and little/no compression with the lever up and slower spinning with compression when down).

The weird thing is just that the flywheel and/or hand crank are seemingly not sufficient to rotate the engine over when the decompression lever is up. Not sure if this is expected or due to where the pistons are or similar

@supersailor It definitely seems dangerous!

 

[bgary]

Anyone have tips or experience hand starting (via hand crank) an engine?

Experience, but no tips

Years ago one of the boats I raced on had a 3-cylinder diesel we'd (sometimes have to) hand crank.

No idea what make/model it was but there was a decompression lever for each cylinder. Pop all three of them open, get two guys cranking and then once it was turning pretty well a third guy would close the lever for the middle cylinder (no idea why that one, but it worked) and the two guys would pull the crank out of its socket.

Might take a couple of tries, but once the engine was chugging on that one cylinder, he'd close the other two. Required a bit of practice but was doable.

 

[bgary]

Added: found a thread on Cruiser Forum:

Hand Cranking Volvo MD7B - Cruisers & Sailing Forums

I have just acquired a 1983 boat with its original Volvo MD7B engine . The engine is in good condition. I got a new hand crank from Volvo . However, the new hand crank is very tight on the crank shaft

www.cruisersforum.com

 

[Alan Gomes]

My little Yanmar 1GM also has a crank. I've never been able to start the engine using it. I also question how safe it would be if it did fire in terms of, e.g., breaking my arm. I've decided not to mess with it.

The decompression lever could be important, though, in case of needing to start with low batteries. I did test this out by rigging a length of small diameter line from the lever to the cockpit via my port cockpit locker (with the lid opened). The line leads in such a way that I can pull on it to pull back the decompression lever, turn over the now-easily rotatable engine with the ignition key, and then release the line to close the decompression lever in order to allow the engine to fire. I have tested this and it works well. Since I often single hand, I wanted to have a way to pull back the decompression lever when I was by myself. If I had a friend aboard I would not need to rig up the line, since that person could be working the lever at the engine while I was above operating the ignition key.

I've not yet had to do this out of need, since my batteries (so far) have never gotten so low that I couldn't crank the engine. But I did test it to confirm that it does work for if and when I should need it.

 

[David Grimm]

FYI. Just be careful!

https://www.hemmings.com/stories/2012/02/27/the-accident-that-started-it-all

 

[reginaldobaker]

Have never hand crank started any engine before - just pull starting small gas motors and roll starting a manual transmission automobile. But, for sure, heard stories when I was a kid about old crank starts being very dangerous. The thumb goes inline with the rest of the fingers!

Have seen some remarks online how diesel engines are not prone to "kicking back", not sure if there's any truth to this. The crank handle for this volvo automatically disconnects when rotated counterclockwise so that's somewhat reassuring. It also seems important to disengage the crank handle before flipping down the decompression lever.

Go niners

 

[reginaldobaker]

After swapping the batteries for another set of known goods there doesn’t appear to be any increase/change in crank speed.
Maybe that’s a bit more evidence to suggest the starter is going out.

Regardless I still cannot get the engine to rotate at all with the hand crank and decompression lever raised. Attached is a picture of the hand crank shaft where it fits onto the engine - one side is pretty bent. Maybe this is evidence to suggest a previous owner/individual put a lot of effort into attempting to rotate the engine via hand crank.

A few months back I replaced the timing belt on a VW (1.9 alh tdi) - part of the procedure is turning over the engine by hand multiple revolutions, so I’m somewhat familiar with the effort needed to turn over the pistons of an engine.

not sure why the volvo would be so “stuck” and am pondering if this happens to share a similar root cause to the slow cranking (no evidence suggests this other than correlation - the engine has never been known to turn over via hand crank)

A concurrent project happens to be rebuilding (new brushes and solenoid) the starter motor on the above mentioned VW.
Have no prior experience rebuilding starter motors so hopefully can take the learnings from the VW starter rebuild and try to apply that to the Volvo starter. Both starters are Bosch units, though about 25 years apart.

there appear to be websites selling starter rebuild parts, used/refurb units, and new knockoff replacement units as well for the Volvo.

Am trending towards rebuilding if possible.

 

[Frank Langer]

After swapping the batteries for another set of known goods there doesn’t appear to be any increase/change in crank speed.
Maybe that’s a bit more evidence to suggest the starter is going out.

Regardless I still cannot get the engine to rotate at all with the hand crank and decompression lever raised. Attached is a picture of the hand crank shaft where it fits onto the engine - one side is pretty bent. Maybe this is evidence to suggest a previous owner/individual put a lot of effort into attempting to rotate the engine via hand crank.

A few months back I replaced the timing belt on a VW (1.9 alh tdi) - part of the procedure is turning over the engine by hand multiple revolutions, so I’m somewhat familiar with the effort needed to turn over the pistons of an engine.

not sure why the volvo would be so “stuck” and am pondering if this happens to share a similar root cause to the slow cranking (no evidence suggests this other than correlation - the engine has never been known to turn over via hand crank)

A concurrent project happens to be rebuilding (new brushes and solenoid) the starter motor on the above mentioned VW.
Have no prior experience rebuilding starter motors so hopefully can take the learnings from the VW starter rebuild and try to apply that to the Volvo starter. Both starters are Bosch units, though about 25 years apart.

there appear to be websites selling starter rebuild parts, used/refurb units, and new knockoff replacement units as well for the Volvo.

Am trending towards rebuilding if possible.

A few years ago I had the starter rebuilt on our boat. I took it to a local auto shop that rebuilds starters and alternators and they did it for about $100 Canadian. It would likely cost a bit more now, but might still be worth a try.
Frank

 

[Prairie Schooner]

The distortion of the handle could be the result of a rocky disengagement after the motor started. The old Peterson 34 I raced on for many years spent a summer without a working starter for its two-lung Yanmar. We were hand crank starting it 2-4 times a week. There was a sacrificial pin and ratchet setup but if you didn't get the handle out of the way quick-like it could rattle around with some force. To your point though, with comprehension released, it wasn't that hard to turn. Once spinning, we did find that a squirt of starter fluid helped it fire up.

 

[Alan Gomes]

Once spinning, we did find that a squirt of starter fluid helped it fire up.

I don't think starter fluid is such a good idea.

 

[David Grimm]

Have you tried removing the v-belt? May be a bad alternator or water pump bearing causing the slow crank/no crank by hand.

 

[Prairie Schooner]

I don't think starter fluid is such a good idea.

Why do you say that Alan? The skipper was an incredible sailor, but kind of devil-may-care when it comes to mechanical stuff.

 

[Alan Gomes]

Why do you say that Alan? The skipper was an incredible sailor, but kind of devil-may-care when it comes to mechanical stuff.

First, I do note that some starting fluids are marketed for both diesel and gas engines. However, I would still say it's risky, though it would depend on the characteristics of the particular starting fluid and aspects of the engine, including whether it has glow plugs.

The potential for damage arises because of the volatility of starting fluid. For one thing, the glow plugs (if present) could ignite the fluid all by themselves when the engine is not cranking. Even apart from glow plugs, depending on the kind and amount of starting fluid one sprays into the cylinder, you could possibly damage rods or blow a head gasket or do other unsavory things to the engine.

One may well get away with doing this, but it's not a risk I'd want to take with any engine I own. If I needed starting fluid to make the engine fire up, I think I'd spend my time instead trying to get to the bottom of why it won't start rather than using starter fluid as a shortcut.

 

[Prairie Schooner]

@Alan Gomes Thanks Alan. One more reason I'm grateful for this community and everyone who contributes.
J

 

[Alan Gomes]

@Alan Gomes Thanks Alan. One more reason I'm grateful for this community and everyone who contributes.
J

You are very welcome.

I'm no expert on this, mind you. And it is a controversial subject, as you'll see if you Google it. I just talked to a mechanical engineer friend of mine, and he would not advise using it for the reasons stated. To me it's too big of a risk and not the real solution to the problem anyway. Just my opinion, FWIW.

 

[reginaldobaker]

Another option is to blow warm air into the air intake with a blow drier/heat gun.
Have never used starting fluid either. Least on this Volvo the air intake is kind of a kneel + reach around to access so both methods share similar impracticalities

 

[Kenneth K]

After swapping the batteries for another set of known goods there doesn’t appear to be any increase/change in crank speed.

Have you cranked the engine, via the starter motor, with the decompression lever open?

With the decompression lever open, the engine should turn over much quicker and should sound very different--a higher pitched electric motor whine that sounds as if the starter motor is running without cranking the engine (even though it is cranking the engine).

If you don't notice this difference (stater cranking with and without the decompression lever open), then your decompression lever linkage is likely not attached. As Doug C. said, you'd have to remove the valve cover to check/fix this. This, in itself, won't fix your starting problems, but it would troubleshoot your decompression lever.

With my decompression lever open (Universal M25), I can turn the engine over using one hand on the fresh-water-pump pulley. In fact, I turn the engine over a few times by hand like this during the winter months just so the raw-water impeller blades get rotated a bit versus sitting statically deformed all winter long.