The engine in my boat,a Yanmar 4JH4ae, is getting air into the system requiring me to open the throttle almost wide open and cranking for a while to get it running. The engine runs fine otherwise. I cannot see any fuel leakage and have tightened all hose clamps. has anyone had a similar problem.
Yanmar starting problem
- Thread starter bart
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A fuel leak is usually a telltale as the fuel is much denser than air. Check the bleed screws especially the one on the secondary fuel filter. Other possibilities are slow cranking speed or low engine compression.
@bart , you asked the same question back on Monday.
I suggest you answer the questions posed to you back then in order to solve this problem. The knowledge exists here to solve the problem if you're willing to meet us half way.
Yanmar starting problem
The Yanmar 4JH4AE in my Hunter sailboat is not starting easily due I believe to air getting into the system. If I open up the throttle and crank it for a long period it will eventually start at high rpm which is not good for a cold engine. I have tightened all the hose clamps on the fuel lines...
forums.sailboatowners.com
I suggest you answer the questions posed to you back then in order to solve this problem. The knowledge exists here to solve the problem if you're willing to meet us half way.
Not thoroughly familiar with the 4JH but if it has banjo fittings in the fuel system, I'd suspect those .. they will leak air with out showing liquid leaks. You can source replacements that have rubber on each side.. those work very well to stop that kind of mess.. They are known as "Dowty" washers and can replace the soft copper crush washer and are reusable.
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In another on -line forum I found a Yanmar technical bulletin from 2009 that addresses the intermittent starting problem I have experienced. On some 4JH4AE engines built in 2008 Yanmar found that in a few rare cases air can enter the system through the priming pump on the secondary fuel filter. The fix is achieved by fitting a filter housing from a later engine, a 4JH5, which also requires changing some fuel lines.
Problem solved. I replaced the fuel filter bracket and added a short piece of fuel line as recommended and the engine starts at an idle.
For those interested, your local Yanmar dealer should be able to provide copy of a Yanmar marine service advisory number MSA09-005R (revised) which includes Global Technical Bulletin GTB2009010 from March 20th, 2009.
For those interested, your local Yanmar dealer should be able to provide copy of a Yanmar marine service advisory number MSA09-005R (revised) which includes Global Technical Bulletin GTB2009010 from March 20th, 2009.