Experiencing hard starting on Yanmar 2QM15 (1980 Hunter 33) irrespective of outside (FL)temperature. First start of day difficult and then for the next 10-15 hours no problem at all ,starts immediately. Activating de-compression lever offers significant improvement on first start of day but does not cure the problem. Fuel appears clear, no water. Changed all filters. Recent oil change (15W40).Cannot find any corrosion on starting electrical terminals. Batteries fully charged. Fuel pump appears adequate since engine runs fine after first start(presently using electrical pump). Get cloud of black smoke on starting, then disappears. Would sincerely appreciate any advice with my New Year's resolution.
Hard Starting
- Thread starter tedboi
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Experienced with diesel in general, not necessarily Yanmars. To me what you described is air in the system. When system components cool down, pumps, lines and connections, injectors, shrink and can suck air in by means of vacuum and or gravity. I would start by putting a wrench to all fuel lines, high and low psi. Some think that if fuel isn't leaking out then air can't get in, which is an incorrect assumption. Good luck. Dan
More info
Has it always been hard starting any time and any smoke when it starts and,when you say won't start is it turning over very well but not starting.
Nick
Has it always been hard starting any time and any smoke when it starts and,when you say won't start is it turning over very well but not starting.
Nick
Nick, he is probably right next to you. Fix it for him. 
You are right though. We need more information. The black smoke makes it sound like it is turning over. . .and over and over.
You are right though. We need more information. The black smoke makes it sound like it is turning over. . .and over and over.
Hard starting began about 6 weeks ago. Previously, always started on first crank. Always had some black smoke upon starting but quickly dissipates(this is still true). The engine always starts but now requires intermittent starter for 1-2 minutes. Concern about starter strain.Thank you Nick and Ed
I would not rule out the change in water and ambient temperatures here in FL. Yanmars do not have a heating element so they rely on compression to heat the fuel and air mixture to its flash point. Combine certain factors like a well used engine that may have lost some its compression with cold sluggish oil in the cranckcase which may not allow the starter to turn the engine as needed and a cold air fuel mixture and you may have a combination of factors causing hard starting. Black smoke which signals incomplete combustion may point to the problem. You indicate that activating the decompression lever helps the startup and I would think it did as it gets the engine turning faster and looser. Try opening up the throtle to 2/3 as it increases the amount of air/fuel to be compressed in a sense increasing compression. I think we had a cold snap about 6 weeks ago when you indicate your problems started so don't rule out the weather. Good luck.
Very cold
It's very cold hear lately and the cold may be making things worse for you,can you add some safe way of adding heat tto the engine and help it start without the strain on the starter and do damage.
Until you find out what is causing the hard starting I would warm things up during this cold spell to get it started and running with out making any more problems.
Can you plug in a heater to add heat to the engine over night or a few hours before starting,but be safe with the heat,I once used a small portable propane heater to help when no 110 available.
Are you in a canal in Punta Gorda,its cold and did want to do some sailing today or kayak but waiting for the sun to warm things up.
Nick
It's very cold hear lately and the cold may be making things worse for you,can you add some safe way of adding heat tto the engine and help it start without the strain on the starter and do damage.
Until you find out what is causing the hard starting I would warm things up during this cold spell to get it started and running with out making any more problems.
Can you plug in a heater to add heat to the engine over night or a few hours before starting,but be safe with the heat,I once used a small portable propane heater to help when no 110 available.
Are you in a canal in Punta Gorda,its cold and did want to do some sailing today or kayak but waiting for the sun to warm things up.
Nick
Re: Very cold
Nick, Hard starting began before local cold snap. During the November days of 80+degree and nites of 70 degrees. Will try your heating suggestion and test for air leaks . Symptoms are a mystery since hard start only on first daily crank. Even on cold days, after hard first start, she will fire up easily during the next 10-15 hours. Hope you "get out" today , a bit "refreshing"!! Grateful for your recommendations.
Nick, Hard starting began before local cold snap. During the November days of 80+degree and nites of 70 degrees. Will try your heating suggestion and test for air leaks . Symptoms are a mystery since hard start only on first daily crank. Even on cold days, after hard first start, she will fire up easily during the next 10-15 hours. Hope you "get out" today , a bit "refreshing"!! Grateful for your recommendations.
Not Today
The nice thing about being retired and living in Florida is plenty of days to go sailing if you get some bads ones.
I am making the wife happy today?????? her not me doing the to do list.
Sounds like maybe air getting in the system or some thing else not sure I am no expert for sure.
I guess the hard part is going to be hunting down the problem now
Nick
The nice thing about being retired and living in Florida is plenty of days to go sailing if you get some bads ones.
I am making the wife happy today?????? her not me doing the to do list.
Sounds like maybe air getting in the system or some thing else not sure I am no expert for sure.
I guess the hard part is going to be hunting down the problem now
Nick
You say it only starts hard the first time. How much time goes by before you start it again? Sounds like a slow air leak but could be compression.
Here is a way to eliminate air leaks as the problem. Put a couple of gallons of diesel in an old but clean outboard gas tank. Cut the outboard motor connector off of the hose(hoses are cheap). Attach that hose with a clamp to the input side of the filter. Squeeze the hose bulb until it gets hard. Now try starting the 2QM.
On my old 2QM20 I could start it after having it apart and without bleeding. It was 4 here this morning Nick. Count your blessings.
Here is a way to eliminate air leaks as the problem. Put a couple of gallons of diesel in an old but clean outboard gas tank. Cut the outboard motor connector off of the hose(hoses are cheap). Attach that hose with a clamp to the input side of the filter. Squeeze the hose bulb until it gets hard. Now try starting the 2QM.
On my old 2QM20 I could start it after having it apart and without bleeding. It was 4 here this morning Nick. Count your blessings.
What ED
I think what ED said makes sense and the tank trick is good way to check if easy for you to do or maybe the compresson with warming it up helps with possible poor compression.
Also when did you last check the mixing elbo can cause hard starting,my 2001 2GM got to be hard starting in cold and after cleaning the mixing elbo it ran better and sta4rted easy and had more power than new.
Nick
I think what ED said makes sense and the tank trick is good way to check if easy for you to do or maybe the compresson with warming it up helps with possible poor compression.
Also when did you last check the mixing elbo can cause hard starting,my 2001 2GM got to be hard starting in cold and after cleaning the mixing elbo it ran better and sta4rted easy and had more power than new.
Nick
Cold but
Yes it is but not really complaining because way better than the 2ft snow when up NY for XMAS
Yes it is but not really complaining because way better than the 2ft snow when up NY for XMAS
Good Advice
Ed, Sincerely appreciate your recommendations. Tried the primer bulb, finally. Significantly improved starting! Now to isolate the problem. . ...Maybe a quick fix by permanantly installing primer bulb in fuel line. Tightened all the fuel connections without improvement.Since there are 15 fuel connectors in the system, installing the bulb may be quick fix. Thx again. ted
Ed, Sincerely appreciate your recommendations. Tried the primer bulb, finally. Significantly improved starting! Now to isolate the problem. . ...Maybe a quick fix by permanantly installing primer bulb in fuel line. Tightened all the fuel connections without improvement.Since there are 15 fuel connectors in the system, installing the bulb may be quick fix. Thx again. ted
This thread helped me
Running a 30 year old 2QM15 with similar starting problems. It would start but only after long cranking. A remark here on the site "slow air leaks occur even if fuel does not leak". After carefully using liquid gasket along with a rubber gasket on some of the fittings the problem has gone away. Also on colder mornings another tip on this site was to crank the engine and then let the heat from cranking set in before trying again. Both of these tips seem to work on my engine.
Running a 30 year old 2QM15 with similar starting problems. It would start but only after long cranking. A remark here on the site "slow air leaks occur even if fuel does not leak". After carefully using liquid gasket along with a rubber gasket on some of the fittings the problem has gone away. Also on colder mornings another tip on this site was to crank the engine and then let the heat from cranking set in before trying again. Both of these tips seem to work on my engine.
I greatly improved the speed of starting on my little yanmar sb8 by disconnecting all of the power cables and replacing all of the ends with new terminals. What a difference it makes! I cut all of the old terminals off, stripped back to nice clean wire and with a blow torch attached new terminals.
I also added a generic starter solonoid to the the starter circuit. Huge difference and improvement in starting.
I also replaced all of my fuel lines to make certain the fuel didn't drop down and the engine held it's prime
I also added a generic starter solonoid to the the starter circuit. Huge difference and improvement in starting.
I also replaced all of my fuel lines to make certain the fuel didn't drop down and the engine held it's prime
Ted...
the engine filters on Yanmars have a plastic washer under one of the bleed screws. Over time they age from the heat and can crack on the inner ring where you can't see it. Try replacing them and the O-ring on the filter bowl now that you've tightened all the connections. Next step is to replace all the brass washers as once compressed they don't like to be retightened if removed and will leak.
the engine filters on Yanmars have a plastic washer under one of the bleed screws. Over time they age from the heat and can crack on the inner ring where you can't see it. Try replacing them and the O-ring on the filter bowl now that you've tightened all the connections. Next step is to replace all the brass washers as once compressed they don't like to be retightened if removed and will leak.
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