Evinrude-Carb problem,vapor lock or something else??

[southerncomfort1]

I have a 94 Evinrude intruder 175 carbed motor that runs great most of the time.Go to the lake start it up runs great, run to fishing spot stop fish for say an hour go to leave motor starts right up but hit the throttle it bogs down instantly and dies.What I have learned is if I keep going through that routine I can get it to take off after the 3rd or 4th time or I can sit there and rev the motor in neutral for a while (motor sounds like it's running slightly rough) and this will clear it out to enough take off to my next spot.Once I get past say the first initial 2000 rpms when dealing with the bogging down issue the motor then runs great again in all ranges afterwords until I get to my next spot and turn the motor off to fish for a while then it returns after sitting again.Installed a brand new fuel pump without the vro oil pump(I self mix fuel) due to it leaking but that did not fix the problem.Replaced fuel primer ball still does it it.When fighting issue on the water primer ball is not rock hard but not soft either.Maybe half a pump returns it to rock hard status which does not help anything.Replaced fuel filter and installed a fuel water separator also. I am thinking maybe my carbs are leaking fuel into the motor causing a flooding issue or is this vapor lock which I have read is sometimes a issue on these motors or is this something else?

[staylor]

...to see if the thermostats are functioning properly, the it sounds like your carbs are full of crud and either sticking the floats or restricting flow thru one of the jets. Have you tried punching the key primer after a warm re-start to see if that will keep her running? If this helps then you probably have a clogged jet. The other possibility is the tank vent being restricted or the anti-siphon valve-if used- in your line from the main tank to the motor being partially stuck. This can be tested by hooking up a known good remote tank and hose with bulb to your fuel line on the motor side of the primer bulb. I had a similar issue on my 1993 225 Evinrude- it turned out to be a partially clogged idle jet.
Doug

[southerncomfort1]

Thanks for the reply.I believe thermostats are working fine.If it is the carbs as I really suspect do they need to be torn down and rebuilt or can I get them clean by running a heavy fuel mixture with seafoam from a small auxillary can like when doing a decarb?Thanks

[staylor]

....since the carbs take a lot of time to pull down and clean- plus the cost if you have a dealer /mechanic do it.
Doug

[craig guest]

If the carbs were dirty, it would act the same way when cold. I have a 175 intruder also and it sounds like the vapor lock issue these motors have. Before I went to the trouble of tearing the carbs apart, I would take the motor cover off next time you stop to fish and if the problem goes away, it's the fuel boiling in the carbs. Mine only does it when it's hot out, but I've thought about adding some kind of closeable vent to the top of the cover.

[southerncomfort1]

Guys thanks for the replies.Tonight I was messing around with the motor trying to figure this out.What I did was pulled the drain plugs on the carb bowls all had fuel in them except one.After installing plugs back in I decided to pump the primer ball to refill the carbs with fuel and was thinking of waiting till later to check to see if the carb bowl in question had fuel in it or if it was flooding that cylinder by pulling the plug again I then noticed on the side of the bowl there is a small circle area with a brass looking end visible that was dripping fuel out of it slowly.So now I am thinking this may be part of the problem.I also pulled the spark plugs and this cylinder in question plug end was bone dry where the others seemed to have a very slight amout of oil residue on the electrodes.So maybe a low ideal clogged jet also thinking.Question is can I remove what looks like 4 bolts and pull the carb off then pull the bowl and replace it or do what is necessary to seal that up to stop the leak then just bolt the carb back on and be good to go or will I have to get a manual to synchronize and adjust it.Also what is involved in making sure the jet is clear on this carb. Looking at back of motor bottom right carb.Thanks

[perchjerker]

check your pm's

[southerncomfort1]

check your pm's

Got it and replied thanks a bunch for the info.Anybody else got any thoughts or experience on this also.

[staylor]

....and would probably end up doing all of the carbs together.
Doug

[Pro V1]

I have 1996 175 intruder. Until reading this thread I thought I was the only guy with this motor?

[southerncomfort1]

Ok here is where I am at with this.Took it to the marina who has cleaned the carbs,did a link and sync.,switched prower packs and still did not get problem resolved.(previous marina replaced fuel pump also)He does not think it's heat soak.He took the motor apart to look at heads and called me over to look at it.What he say's is that top right cylinder rings are not making perfect contact and allowing what he calls blowback when the motor sits which causes that cylinder to flood when sitting resulting in the bogging issue after the boat is ran then sits while fishing a length of time.Now having said that he really could explain to me why my compression is still perfect even on this cylinder that he "THINKS" the ring in not making "PERFECT" contact through out the whole cylinder wall.(His words)No matter how hard I looked I just could not see any difference in the cylinders walls but he says to a trained eye he can tell.The one thing that stood out to me was on top of that cylinder head was that it was much cleaner then the rest of them.He suggested we put it back together and just deal with the bogging issue,rebuild it for $4000-5000 or buy a new motor.I am no mechanic but have basic understandings of them so how could a cylinder that has bad rings give perfect compression readings at 2 different marina's? Why does the motor run like a rapped ape down the water easily carrying a heavy load and hitting max rpms but only after being ran then sitting to fish for a period of time does it starts right up but bogs if you hit the throttle right away.If you rev it up a few times seems to clear it out then she runs great again.Like I said I am no mechanic but I thought a compression check is how you test your rings and if you had bad rings then you would be loosing top end performance which I am not,and one cylinder should not bog the whole motor.to me something just does not seem right with his diagnosis.I wonder if a good decarb of the motor could help?To me it seems like a flooding or a lean issue in the whole motor.Maybe it's sucking air? I just don't know at this point what to think or believe.Just bought the wife a new car so not looking to spend big money on a new motor and don't think motor of this vintage is worth 4-5000 dollars on a rebuild.I told him to put it back together and I am picking it up today and I would just deal with it for right now. What to do?..sorry for the long post

[TomP.]

My two cents.... First off if compression is good there is nothing else to say here. If having to rev the engine once or twice and the problem goes away it has to be in my mind a fuel issue. Check and recheck every connection. You mentioned you found a leak on a carb did getting that fixed resolve anything?

Dumb thing how warm has it been? Had a Evinrude XP 150 I had to wrap wash towels around the fuel line running to the motor. Sitting in the sun the fuel in the line would vapories. Some of these engine were bad for vapor lock.

[perchjerker]

heres what I would do.

You know how to duplicate the problem.

You know what cyls are affected.

I would duplicate the problem, but instead of running it and clearing it out, while its doing its bogging thing, shut the motor off and pull the plugs for the affected cylinders, see if they are flooded looking or starving for fuel or whatever. Compare them to a plug on a cyl you know if firing correctly.Maybe have some new plugs ready to pop in the holes, replace the plugs and see what happens.

if its a fuel issue, this may tell you something and help in your diagnosis

I dont know how hard this would be to do to your motor on the water, maybe its too hard, maybe you could run it and tie it to a dock to get the problem to appear and then work on it at the dock

I know, a lot of "maybes" here, LOL

[southerncomfort1]

My two cents.... First off if compression is good there is nothing else to say here. If having to rev the engine once or twice and the problem goes away it has to be in my mind a fuel issue. Check and recheck every connection. You mentioned you found a leak on a carb did getting that fixed resolve anything?

Dumb thing how warm has it been? Had a Evinrude XP 150 I had to wrap wash towels around the fuel line running to the motor. Sitting in the sun the fuel in the line would vapories. Some of these engine were bad for vapor lock.

Thanks Tom...The carb leak has been fixed and in fact all carbs have been gone through and cleaned at the dealer.I agree with you on "it's a fuel problem".What I have done today is a good decarb to make sure everything internally is freed up and clean(did the seafoam and a gal. of fuel/oil mix)Took it to the river after and ran it.Stopped and dropped the kicker switched the T valve for fuel and putted around for about 30 min.Then I put kicker up switched valve to main motor and the thing bogged out twice then took off and ran as usual great.While sitting there putting around with the kicker I started to think about that T valve in the fuel line which was added this spring for the kicker.My problems started after that thing was installed so what I did was come home took it off and ran the main hose straight to the main motor the exact way it was last year.Maybe with a little luck that T valve is my issue.I dont think I will be back on the water till Thursday to test but praying that it is this valve to end this problem then I could just get a small auxiliary tank for the kicker.If this does not cure it it must be vapor lock or heat soak.Might have to try the wet towl trick on the fuel lines.We shall see.Just to be clear my problem happens even when the kicker is not used.I will post next test results as soon as I get them.Thanks

[southerncomfort1]

heres what I would do.

You know how to duplicate the problem.

You know what cyls are affected.

I would duplicate the problem, but instead of running it and clearing it out, while its doing its bogging thing, shut the motor off and pull the plugs for the affected cylinders, see if they are flooded looking or starving for fuel or whatever. Compare them to a plug on a cyl you know if firing correctly.Maybe have some new plugs ready to pop in the holes, replace the plugs and see what happens.

if its a fuel issue, this may tell you something and help in your diagnosis

I dont know how hard this would be to do to your motor on the water, maybe its too hard, maybe you could run it and tie it to a dock to get the problem to appear and then work on it at the dock

I know, a lot of "maybes" here, LOL

Good points...As I posted above hoping maybe that T valve is my problem since it seems my problems started sometime after that was installed.Wish I would of thought of it earlier.Guess I will find out next time out as I have eliminated it for testing purposes.Thanks

[perchjerker]

yea, could well be that valve!!!!

[tzonetom]

I had the exact same problem with my 96 175 Intruder. My solution was the fuel bulb. It worked a lot better after I changed it out. Check to see if the bulb is staying hard. When mine would start to bog down, if someone squeezed the bulb, she go just fine.

I also had the carbs cleaned at winterizing, and she fired right up in the spring. I didn't get a chance to use it much before I sold it this spring, but it worked great.

[southerncomfort1]

I had the exact same problem with my 96 175 Intruder. My solution was the fuel bulb. It worked a lot better after I changed it out. Check to see if the bulb is staying hard. When mine would start to bog down, if someone squeezed the bulb, she go just fine.

I also had the carbs cleaned at winterizing, and she fired right up in the spring. I didn't get a chance to use it much before I sold it this spring, but it worked great.

Appreciate the info.I already did replace the bulb unfortunately it did not help.Bulb stays firm but I have noticed that if I start it and she bogs I can then go back and maybe pump it once .I wonder if my T valve is bad and allowing fuel to drain back toward the tank and fuel water separator creating a air pocket in the line after sitting then when I hit it under load it bogs out until I clear it out.On the surface it seems logical so I have removed the T valve for testing purposes and have ran main fuel line straight into the bulb going direct to main motor.Will report what happens most likely Thursday.Just for info my main line came into splash well right into a T valve then to each motor(kicker,main) with each having it's own primer bulb between the T and motor.Thanks everyone for the help and ideas.

Is there anything in the tank that is suppose to prevent fuel to drain back in kinda like the check valve in the primer bulb?Or is it just the vacuum holding the fuel in the line from the primer bulb back to the tank in what should be a air tight fuel line system?

[perchjerker]

my tank has an anti siphon check valve in the fuel tank outlet

[staylor]

...if it still bogs have someone keep pumping the bulb firm to see if its a stuck anti-siphon valve or a plugged air vent in the fuel cap. If pumping the bulb fixes it, try loosening the fuel fill cap and try again. If it still acts up the antisiphon valve is either at the top of the tank or in-line in the first few inches of line above the tank. Remove the valve and either try with no valve or if its hardplumbed to the tank top them take the valve apart and remove the internal poppet and the spring that is usally there to preload it. Then try again. If pumping the bulb fixes it and it's not the antisiphon valve or fuel fill cap then you're down to the hose and bulb having a leak or the fuel pump.
Doug

[perchjerker]

could also have a hose collapsing internally. They have a lining inside and they can sometimes seperate and collapse partially and can be a bear to find because it looks normal from the outside. My dealer has one that he uses for show and tell.

Not likely, but just something else to add to your list.

[southerncomfort1]

...if it still bogs have someone keep pumping the bulb firm to see if its a stuck anti-siphon valve or a plugged air vent in the fuel cap. If pumping the bulb fixes it, try loosening the fuel fill cap and try again. If it still acts up the antisiphon valve is either at the top of the tank or in-line in the first few inches of line above the tank. Remove the valve and either try with no valve or if its hardplumbed to the tank top them take the valve apart and remove the internal poppet and the spring that is usally there to preload it. Then try again. If pumping the bulb fixes it and it's not the antisiphon valve or fuel fill cap then you're down to the hose and bulb having a leak or the fuel pump.
Doug

Appreciate the info.Will do my best to test most of this out soon.Really hoping it's just the T valve but that would be too simple.Question...If I was getting heat soak/vapor lock wouldn't pumping the ball really hard possibly also help break it and get the needed fuel to the motor?I talked to a old Evinrude mechanic today on the phone and he said it's classic heat soak and said the fix is to change the air bleed jets to make the motor run richer.He no longer is a Evinrude dealer and said he would get back to me after he did a little research on parts and pricing.What do you think? Thought if nothing else seems to fix it may be worth a shot but he is better then a hour drive from here so I want to test everything else before going that direction.Thanks again...Fyi.. brand new fuel pump already installed...

[southerncomfort1]

could also have a hose collapsing internally. They have a lining inside and they can sometimes seperate and collapse partially and can be a bear to find because it looks normal from the outside. My dealer has one that he uses for show and tell.

Not likely, but just something else to add to your list.

I will add this to my list of maybe's to check.I thought I had covered just about everything but the list just keeps growing of possibilities....When and where will it end....LOL ... Thanks for the info bud.....

[staylor]

I had this issue years back on a 225 V-6. I found the problem on summer days on a warm re-start after drifting for 30 minutes or so. I found that the quick fix was to start the motor and let it idle in neutral for about a minute before putting it in gear and planing. I ended up doing just what the old time Evinrude Mechanic said- I opened the air bleeds, which on my particular V-6 were adjustable- this fixed it.
Doug

[southerncomfort1]

I had this issue years back on a 225 V-6. I found the problem on summer days on a warm re-start after drifting for 30 minutes or so. I found that the quick fix was to start the motor and let it idle in neutral for about a minute before putting it in gear and planing. I ended up doing just what the old time Evinrude Mechanic said- I opened the air bleeds, which on my particular V-6 were adjustable- this fixed it.
Doug

Yepper...If I let it idle for a minute or so in nuetral then I can go and get on plane.Interesting coincidence...If the air bleed jets are changed does the timing or idle have to be adjusted also?Just in case I decide to do this my self if the other test don't resolve this.The old Evinrude mechanic really was helpful on the phone but gave me the impression he did not need or want the work since he no longer is a Evinrude dealer and would have to special order the jets and did not call back as of yet.

[staylor]

I just changed the jets, it seemed to have very little effect on idle speed. I know that if the jets are totally wrong then the change may alter the idle speed- but since the factory did the original jetting, they won't be off enough to make a difference in anything else when you change them. On my 225 with adjustable air bleeds it was only a 1/4 turn difference between bog and no bog.
Doug

[southerncomfort1]

Sorry it took so long to report back on my results but I wanted to get a few trips in first to make sure it was really fixed before posting.To make a long story short I replaced a couple of lines and clamps around the fuel pump area and reconnected with a good screw clamp the fuel line coming into the motor.Really believe this was the culprit- never leaking but sucking air.After 3 trips no bogging out so I think I have finally got this thing fixed finally.Thank you to everyone that gave me suggestions and tried to help it was much appreciated.Keeping fingers crossed all is good from here on out.