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Fuel Leak

T

ttruchot

New member
Our Honda 90 4 stroke appears to leak fuel when not running. The leak appears to come from the idle port. Does anyone know what the problem could be. We also seem to get a lot of smoke out the port when running.
 
When you say idle port, I assume you are talking about the opening on the back of the engine about midway up.

Check inside the case and see if the fuel is not coming from inside the case and leaking out the port area. You could have a leaky fuel line or overflowing carburator. Have someone squeeze the fuel bulb when the engine is not running to help find the leak, if there is any.

On the other hand, you could have a ruptured diaphragm in one of your fuel pumps and the fuel is leaking into the crankcase. This normally would be seen as your oil level getting higher and diluted.

If you squeeze the fuel bulb, does the flow of the fuel out the port increase.

Mike
 
This is a Honda 90 4 stroke fuel injected engine. I was not totally correct in that it leaks from the idle port when the switch is in the on position or the motor is running - if the switch is in the on position but the motor is not running you see a small dispursement in the water.

Another question is how much water should be coming from the tattletail when the engine is in idle. It is not a high pressure stream when idling.
 
I would follow the fuel line from where it comes into the motor, through the low pressure filter (near top of the engine), to the low pressure pump and then to the vst.

Make sure the fuel drain on the vst is closed.

How long has this been going on? Did you winterize it in the fall?

Mike
 
This just happend when the local shop took this motor and installed it on our new pontoon. We are certain the motor was dropped although we have not accused them of this. It ran this way when we got the boat back it ran perfectly before they got it. They do not want to deal with the problem and will not even take our calls. They did say they replaced the fuel line from the tank to the fuel rail. We would like to know if they removed the rail (not changing the O rings) to install this but we cannot get them to answer us. My husband is trying to fix himself with the help of Helm manual as it is more than 200 miles to the next dealer. Since the housing is cracked now near where this line hooks on to the fuel rail as well as the fin bent, as well as the prop we are quite certain this is how the fuel line broke off from the rail rather than their just trying to tighten it as they noticed a leak. I think if there was a leak the engine would have run poorly before and it ran perfectly never missing and starting on the first twist of the key - now it will not start until many cranks and we think it is getting to much fuel hence the fuel running out the idle port and a lot of white smoke also coming from there - it never did that before. If you turn the boat key on but do not start it the fuel will start disapating from the idle port. I would be so thankful for any ideas you can give me
 
The leak makes some sense now.

I would start by removing the port side cover. That should expose most of the fuel lines and the vapor separator. The line from the vapor separator to the fuel rail should be the bottom one. If you see no leaks at the vst or the high pressure line, check all along the fuel rail....which you have probably already checked. This will give you best visual access to the fuel lines.

Hopefully, they did not connect it properly (and the leak is apparent) and you are losing fuel pressure. Thus the hard starting and poor running.

Check the injectors closely in case one is cracked.

If no visible leaks....

If your husband has a compression gauge, he may want to check the compression in the cylinders. There could be a crack in the head.

What housing is cracked? Any pictures available?

Are any of the ignition coils cracked or broken? I know that is the other side, but engines do bounce when they are dropped. I know they do not leak fuel, but are critical for runability.

Cycling the key on and off will run the high pressure fuel pump for 2 seconds each time. Have someone do that while the other is looking for leaks. It the leak is external, it will show up pretty quick.

The fuel may be easier to see if you do this in a shaded area and use a flashlight. The light from the flashlight will reflect better when it hits the fuel.

Hope this helps. Unfortunately, as good as the Helm manual is, it will not tell you what to look for if something is physically broken. Also, I hope the fuel is not coming out of the actual idle port tube. It goes up before it goes out the back of the motor. That would mean that it is full of fuel.

Mike
 
Sorry I could not respond earlier, but I am deep in the mountainsof Montana and rely on my cell phone for a data connection tethered to mylaptop. I simply could not get aconnection today. But I do have quite astory to tell.
Thanks so much for your help – with the procedure you sentlast we were able to find a leak due mostly to the “2 second rule” andflashlight idea you sent. Previously myhusband had turned the key on gone back to the motor and was unable to seeanything but with me running the key switch while he looked he was able to spota leak near the first injector.
Interestingly enough upon further study and removal of theleft shroud we were able to see damage all up the engine. Had you placed a straight edge from the finto the top of the motor the damage was evident all along it, further justifyingour thoughts the engine had been dropped. It was evident that a great deal of force was placed upon the top boltthat secures the fuel rail. All boltsother than that were coated with a color or paint (assumedly so one could tellif they were tampered with for warranty purposes) however this top bolt had nocoloring and it appeared it had been smashed on the end distorting the threadsbeyond the nut. We removed this bolt butwere unable to unscrew the nut but rather had to remove it by removing thewhole bolt from the head end. Uponremoval of this bolt it was actually bent in the middle. The top of the fuel rail was also smashed abit on the corner.
Back to the injector. Although we could not see any cracks when we removed the fuel rail with thekey off the top injector continued to pour out gas. The others did not. So obviously there is something wrong withthis injector. We ordered a new injectoras well as new pin with a nut and both sets of O rings for the injector. We are hoping this is the extent of theproblem other than the cosmetic things we see on the case. We did not do the compression test yet butwill upon reassembling the engine. Witha visual inspection we could not see any damage to the head end of the bolt orto the fuel rail other than the smashed corner.
Is there anything else we should look for along the fuelrail or in this area? Will we need toreset the computer after fixing? We havenot tried to do this as it was running perfectly before this damage.
Again I cannot thank you enough for your help. We truly appreciate all your suggestions. You are welcome at this cabin on the lake anytime. I will let you know uponreassembly just what happened hopefully the engine will run like it did. Thank you again. [email protected]
 
Sorry I could not respond earlier, but I am deep in the mountainsof Montana and rely on my cell phone for a data connection tethered to mylaptop. I simply could not get aconnection today. But I do have quite astory to tell.
Thanks so much for your help – with the procedure you sentlast we were able to find a leak due mostly to the “2 second rule” andflashlight idea you sent. Previously myhusband had turned the key on gone back to the motor and was unable to seeanything but with me running the key switch while he looked he was able to spota leak near the first injector.
Interestingly enough upon further study and removal of theleft shroud we were able to see damage all up the engine. Had you placed a straight edge from the finto the top of the motor the damage was evident all along it, further justifyingour thoughts the engine had been dropped. It was evident that a great deal of force was placed upon the top boltthat secures the fuel rail. All boltsother than that were coated with a color or paint (assumedly so one could tellif they were tampered with for warranty purposes) however this top bolt had nocoloring and it appeared it had been smashed on the end distorting the threadsbeyond the nut. We removed this bolt butwere unable to unscrew the nut but rather had to remove it by removing thewhole bolt from the head end. Uponremoval of this bolt it was actually bent in the middle. The top of the fuel rail was also smashed abit on the corner.
Back to the injector. Although we could not see any cracks when we removed the fuel rail with thekey off the top injector continued to pour out gas. The others did not. So obviously there is something wrong withthis injector. We ordered a new injectoras well as new pin with a nut and both sets of O rings for the injector. We are hoping this is the extent of theproblem other than the cosmetic things we see on the case. We did not do the compression test yet butwill upon reassembling the engine. Witha visual inspection we could not see any damage to the head end of the bolt orto the fuel rail other than the smashed corner.
Is there anything else we should look for along the fuelrail or in this area? Will we need toreset the computer after fixing? We havenot tried to do this as it was running perfectly before this damage.
Again I cannot thank you enough for your help. We truly appreciate all your suggestions. You are welcome at this cabin on the lake anytime. I will let you know uponreassembly just what happened hopefully the engine will run like it did. Thank you again. [email protected]
 
As long as you has not set any alarms, you should not have to reset the computer. Fuel leaks are not recongnized by the computer.

If the fuel rail looks bent or questionable, you may have to replace it.

When you get the fuel system back together with no leaks, try starting it on a hose with the covers still off and verify that all leaks and issues are resolved.

As for a visit to the cabin...
My 14 kids and their families and I are on our way....it will be a couple of days before we arrive... LOL

Mike
 
I will be expecting you 14 kids families and all. Thank you again I will report back when parts are received and we get all back together. I cannot tell you how much we appreciate your help.
 
Last of the parts to arrive tomorrow - everything looking good. Don't forget - bring the dogs too!!! Will write again tomorrow night
 
Got everything together but did not have a large amount of time to run. On inspection there appeared to be no more leaks and when we tested in the water - motor ran like it did before - started great no white smoke or gas coming out of the engine. No leaking of gas at all that we could tell. May not get a chance to run the boat around tomorrow but plan to run it extensively on Sunday - will let you know again that all is well. Cannot thank you enough for all the help. Once we had that great advice we were able to see the problem and correct it. Now time will tell if there is further damage but it runs great right now
 
We ran the engine extensively on sunday and today as well. We believe it is fixed. It seems to run well and start like it used to. We changed the shroud peices that were damaged and the black brace connector piece in the back that also has the tattletale in it. It had seemed since we changed the impeller that it was not pumping as much through the tattletale as it used to - but we found when changing that black piece the connection had been knocked loose there as well as breaking the connections on the side of the brace. We changed the shroud pieces that were cracked as well. We did not change the bottom unit where the skag was bent and damaged - we thought we could grind it off a bit rather than change it. It still appears to be long enough to protect the prop. So glad to have it up and running again .
 
From the steam separator, fuel rail line should be the bottom. If you see no lines at the VST or high-pressure leak check fuel rail all along .... you may have been selected. This will give you the best visual access to the fuel line.Tera Items...
 
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