Think an intermittent (only when hot) failure of the cdi fits the bill - will prob invest and see what happens.I have the same exact problem with my 1997 Yamaha 200HP motor. Always a rough start. Once I get going I'm fine, but occasionally after running for a while or if the motor has been sitting in hot sun for a while (eg when I'm beached for a few hours or drift fishing for a while) then I can't get it to start at all. The motor will not turn over. Almost sounds like it's wheezing. I've had the motor looked at for 2 consecutive years during winterizing and my Grady dealer can't find anything wrong.
My only guess is that it has something to do with the motor being hot but I have no clue what I'm talking about. In each case, it eventually started after 30-45 min of trying and resting.
1996 yamaha txru - runs fine then wont start after a few hours
- Thread starter imjus4u2nv
- Start date
Interesting, I will try the washdown trick and see if it helps cool down engine quicker - worst part is when I go out now im trying to get stuck to replicate the problem lol
That motor isn't terribly sophisticated so I think that something doesn't like getting hot. One common source is vapor lock but I don't think based on your exact symptoms that is the problem. So that leaves spark. Unfortunately there are causes that can be quite hard to track down since they are intermittent.
Areas of concern are ECU which I don't think is the problem (only because they don't fail like yours does unless water cooled and there is a cooling issue)\
A bad connection that acts up when hot,
More ;likely a bad stator or pulser. Both of these are tricky to test but doable but are if intermittent, may test OK but act up when hot.
All three components are expensive so I wouldn't run out and buy parts yet.
I might try the following. Try to cool off some components after the failure to see if you can narrow down the possibilities. I am not a fan of spraying cool water on a hot engine but it occurred to me that if you have a cordless leaf blower, after a failure you could remove the cowling and maybe the flywheel cover and blow air under the flywheel for a few minutes and see if the motor fires up quicker.
I haven't tried this method but who knows
Likewise if that doesn't help you can use the blower to cool off the ECU and see if that helps shorten the time it takes for the motor to refire.
Areas of concern are ECU which I don't think is the problem (only because they don't fail like yours does unless water cooled and there is a cooling issue)\
A bad connection that acts up when hot,
More ;likely a bad stator or pulser. Both of these are tricky to test but doable but are if intermittent, may test OK but act up when hot.
All three components are expensive so I wouldn't run out and buy parts yet.
I might try the following. Try to cool off some components after the failure to see if you can narrow down the possibilities. I am not a fan of spraying cool water on a hot engine but it occurred to me that if you have a cordless leaf blower, after a failure you could remove the cowling and maybe the flywheel cover and blow air under the flywheel for a few minutes and see if the motor fires up quicker.
I haven't tried this method but who knows
Likewise if that doesn't help you can use the blower to cool off the ECU and see if that helps shorten the time it takes for the motor to refire.
Great info - wasn't really thinking about the stator%pulser, will try with the ice method which I jave heard worked for the ecu, and then next time try to work on cooling the stator. Was just going to buy the ecu but will give it another round or two of testing first.That motor isn't terribly sophisticated so I think that something doesn't like getting hot. One common source is vapor lock but I don't think based on your exact symptoms that is the problem. So that leaves spark. Unfortunately there are causes that can be quite hard to track down since they are intermittent.
Areas of concern are ECU which I don't think is the problem (only because they don't fail like yours does unless water cooled and there is a cooling issue)\
A bad connection that acts up when hot,
More ;likely a bad stator or pulser. Both of these are tricky to test but doable but are if intermittent, may test OK but act up when hot.
All three components are expensive so I wouldn't run out and buy parts yet.
I might try the following. Try to cool off some components after the failure to see if you can narrow down the possibilities. I am not a fan of spraying cool water on a hot engine but it occurred to me that if you have a cordless leaf blower, after a failure you could remove the cowling and maybe the flywheel cover and blow air under the flywheel for a few minutes and see if the motor fires up quicker.
I haven't tried this method but who knows
Likewise if that doesn't help you can use the blower to cool off the ECU and see if that helps shorten the time it takes for the motor to refire.
Note that if you buy a new ECU, depending on your motor, you may have to get the boat to an authorized dealer to flash it and program in the old data such as engine hours. That will add cost and even time delay since dealers are pretty backed up with work.
If you are convinced the ECU is bad, Instead of buying an ECU and installing it yourself, I recommend that you let an authorized dealer diagnose and repair the motor. You want someone to be accountable for the repair which might be expensive.
It is also one thing when a repair facility says they found a loose connection, repaired it, charged you for the work but the problem still exists but a different case when they replace expensive parts, charge you but the problem isn't fixed. Unfortunately, I see this often and it can get very expensive and frustrating. Being able to replicate the problem is key so ask if the repair facility was able to do so, either at sea or in the yard before replacing parts.
Note that running the engine for several hours does not mean you should get charged labor for all that time, just the time to set up the test and occasionally check for the problem.
The same goes for your testing. Can you create the problem without having to boat for hours?
If you are convinced the ECU is bad, Instead of buying an ECU and installing it yourself, I recommend that you let an authorized dealer diagnose and repair the motor. You want someone to be accountable for the repair which might be expensive.
It is also one thing when a repair facility says they found a loose connection, repaired it, charged you for the work but the problem still exists but a different case when they replace expensive parts, charge you but the problem isn't fixed. Unfortunately, I see this often and it can get very expensive and frustrating. Being able to replicate the problem is key so ask if the repair facility was able to do so, either at sea or in the yard before replacing parts.
Note that running the engine for several hours does not mean you should get charged labor for all that time, just the time to set up the test and occasionally check for the problem.
The same goes for your testing. Can you create the problem without having to boat for hours?
UPDATE: so I went through the engine methodically. Bad fuel bulb replaced and new hose bc looked liked inside liner was separating from rubber part (and blew out all fuel lines and vent tube), tested all coils (one bad one by ohm meter readings - replaced all 6 but still not running right although sounded better, so then I rebuilt all three carbs - bingo, she is running like a dream! Also the tested rectifier for good measure and was good.
Thanks for the all help everyone.
Thanks for the all help everyone.