No Power from engine
- Thread starter Onlinerandy
- Start date
Yanmar
I guess you could look for best price on the internet search or just go to
yanmar dealer and it is a 2 part part and need to be taken apart to replace and 4 bolts hold the whole thing on the back of engine.
Tons of info on this forum all about how many boaters here have done to change thiers,some times if not badly rusted it can be cleaned out but not easy to do that and most replace it.
What I did many years ago was take the 4 bolts off and remove it and start
it up and run it a short time and see if it runs better,mine was badly plugged and
was very hard starting and when I removed it the engine started in a second and ran fantastic when I was able to clean it out.
Older engines do get the mixing elbo in bad shape and most times need to be replaced .
I take mine off and had a repair shop take apart for me.
Nick
I guess you could look for best price on the internet search or just go to
yanmar dealer and it is a 2 part part and need to be taken apart to replace and 4 bolts hold the whole thing on the back of engine.
Tons of info on this forum all about how many boaters here have done to change thiers,some times if not badly rusted it can be cleaned out but not easy to do that and most replace it.
What I did many years ago was take the 4 bolts off and remove it and start
it up and run it a short time and see if it runs better,mine was badly plugged and
was very hard starting and when I removed it the engine started in a second and ran fantastic when I was able to clean it out.
Older engines do get the mixing elbo in bad shape and most times need to be replaced .
I take mine off and had a repair shop take apart for me.
Nick
The below link connects to a SBO thread with a great DIY how-to by misha93 (who hasn't posted for awhile). I saved the link for the day I will need to replace my now four year young/old (depends on how one looks at age) Yanmar official replacement cast iron mixing elbow rusts through again.
http://forums.hunter.sailboatowners.com/showthread.php?t=156870
Misha93 hasn't yet reported if his mixing elbow functioned well. The one aspect that I don't know about is that my factory mixing elbow has two chambers in it. One for the cooling water and the other for the exhaust gases. On the exhaust manifold end, the two are separate. On the bottom down-slope end, they combine. This arrangement prevents the water from backing up into the exhaust manifold. Misha93's design accomplishes this function. But the other purpose of the dual chamber design is so that the cooling water keeps the mixing elbow itself cool. I am not sure if Misha93's arrangement has enough surface area where the cooling water pipe joins into his elbow to accomplish the cooling. And if not, whether it really makes a difference as long as the mixing water cools the exhaust further down where it enters the rubber tubing and water lift muffler.
http://forums.hunter.sailboatowners.com/showthread.php?t=156870
http://forums.hunter.sailboatowners.com/showthread.php?t=156870
Misha93 hasn't yet reported if his mixing elbow functioned well. The one aspect that I don't know about is that my factory mixing elbow has two chambers in it. One for the cooling water and the other for the exhaust gases. On the exhaust manifold end, the two are separate. On the bottom down-slope end, they combine. This arrangement prevents the water from backing up into the exhaust manifold. Misha93's design accomplishes this function. But the other purpose of the dual chamber design is so that the cooling water keeps the mixing elbow itself cool. I am not sure if Misha93's arrangement has enough surface area where the cooling water pipe joins into his elbow to accomplish the cooling. And if not, whether it really makes a difference as long as the mixing water cools the exhaust further down where it enters the rubber tubing and water lift muffler.
http://forums.hunter.sailboatowners.com/showthread.php?t=156870
Has this presented itself after the rebuild?
Do you get higher rpm, 3400, if you throttle up in neutral?
This checks to make sure your linkage and max rpm stops on the linkage are ok.
If you can,t throttle up to 3000-3400 it will not be a prop problem and may be:
1) A faulty injector which may not be spraying properly but instead dripping fuel on the inject cycle. This will present itself with blue smoke( unspent fuel), lack of power and likely an engine vibration. The injectors need to be rebuilt on an engine rebuild. Also good to have a spare on board, easy to change out.
2) the injector timing is accomplished by shimming the high pressure fuel pump, Which operates off a camshaft. When rebuilding, note the number of shims under the high pressure fuel pump when dis-assembling and re-shim accordingly when you put it back together with new shims. This injector timing, similar to spark timing on a gas engine needs to be correct to get the maximum amount of power out of your engine; injects fuel at the correct moment in the combustion cycle.
3) check your low pressure and high pressure fuel filters, blockage could also cause low power.
4) blue smoke and low power can also be caused by low compression in the engine cylinders. Diesel need high compression ratio to ensure spontaneous burn in diesel cycle. When rebuilt, were the cylinders over- bored and new piston/ rings installed? The head should also be rebuilt to ensure valve stems/ seals along with valves replaced. A poor valve seat will lower your compression and reduce power. Worn valve stems/ seals will let engine oil permeate into cylinder (also blue smoke).
5) make sure air is bled out of the high pressure fuel system. Any air in the injector system will compress during the injection cycle and will cause the injector/s to not operate properly. Can crack the fuel lines on the injectors and crank engine over until just fuel and no air coming out of line, then relighted.
Diesels are very simple engines. Lack of fuel, air, proper injector timing or compression can cause reduced power as mentioned above so ensure these are god before re- pitching your prop.
Reni
Do you get higher rpm, 3400, if you throttle up in neutral?
This checks to make sure your linkage and max rpm stops on the linkage are ok.
If you can,t throttle up to 3000-3400 it will not be a prop problem and may be:
1) A faulty injector which may not be spraying properly but instead dripping fuel on the inject cycle. This will present itself with blue smoke( unspent fuel), lack of power and likely an engine vibration. The injectors need to be rebuilt on an engine rebuild. Also good to have a spare on board, easy to change out.
2) the injector timing is accomplished by shimming the high pressure fuel pump, Which operates off a camshaft. When rebuilding, note the number of shims under the high pressure fuel pump when dis-assembling and re-shim accordingly when you put it back together with new shims. This injector timing, similar to spark timing on a gas engine needs to be correct to get the maximum amount of power out of your engine; injects fuel at the correct moment in the combustion cycle.
3) check your low pressure and high pressure fuel filters, blockage could also cause low power.
4) blue smoke and low power can also be caused by low compression in the engine cylinders. Diesel need high compression ratio to ensure spontaneous burn in diesel cycle. When rebuilt, were the cylinders over- bored and new piston/ rings installed? The head should also be rebuilt to ensure valve stems/ seals along with valves replaced. A poor valve seat will lower your compression and reduce power. Worn valve stems/ seals will let engine oil permeate into cylinder (also blue smoke).
5) make sure air is bled out of the high pressure fuel system. Any air in the injector system will compress during the injection cycle and will cause the injector/s to not operate properly. Can crack the fuel lines on the injectors and crank engine over until just fuel and no air coming out of line, then relighted.
Diesels are very simple engines. Lack of fuel, air, proper injector timing or compression can cause reduced power as mentioned above so ensure these are god before re- pitching your prop.
Reni