95' 175hp won't take throttle with out primer

[ddalton]

Hello All - having a little problem with my 95' 175hp Evinrude. After warm up it won't take throttle with out a shot from the primer. When I start to throttle up the engine will flatten out. If I keep appling throttle it will die. If I engage the primer for a second or two the it rpms come up and I can hammer the throttle.

Starts great cold or warm. Cold and warm idle are OK but with an ocassional sputter after warm up and runs great at all rpm ranges including WOT. Tried squeezing the fuel bulb but doesn't have any effect on issue.

Local shop diagnosed this as bad Power Pack and timing base. Replaced Timing base(optical sensor) Power Pack, plugs, fuel filter and screen. Motor definately runs different for the better but stalling still an issue.

I've ran it 5 or 6 hours now since replacing parts. Plugs look pretty good, dark tan with very little carbon deposit. When I pulled plugs the plug from the top left cyclinder had quite a bit of oil on threads and plug seal. Not sure if that's normal or not but it doesn't seem to smoke excessivily when idling so I think the VRO is working OK. However, the plug from top left cyclinder did have a small amount of carbon deposit while others have none.

Also checked spark advance/throttle linkage timing and set according to manual. If it was out of sync it wasn't by much.

Also notice that carbs on top and intermidiate carbs on right bank are wet with oil/gas. Wipe excess off and it appears again after an short period of use. Not sure if this is normal or indication that bowl gaskets need replaced?

Wondering if idle air mixture is out of whack. Reading Clymers shop manual carb adjustment it says the idle air screws should be two full turns out from light seat. All six of mine are eight turns out from light seat. Is the shop manual correct or is the eight turns correct?

I've spent close to $500 trying to correct this problem so any input would be very much appreciated.

 

[tashasdaddy]

Re: 95' 175hp won't take throttle with out choke

Re: 95' 175hp won't take throttle with out choke

1st having to use the choke, indicates fuel starvation. weak fuel pump, clogged vent on fuel tank, air leak fuel connections, clogged high speed jets in the carbs.

my 1st suggestion is to get rid of the Clymer manual, and by the correct Evinrude manual for your motor (outboardbooks.com). Clymer is known for mistakes.

2nd, get the carb rebuild kits, throughly clean and rebuild your carbs, then do a linc n sinc. and check the items listed above.

also you do not have a choke, you have a primer.

Primer Solenoid
the primer replaced the old choke butterflies in the carborators, pushing in the key activates it, like the old choke plates, but injects fuel directly into the intake.
The red handle is used when your battery is dead, and you have to rope start. You move the handle 180 degrees.
Normal operating position is with the handle back over the body of the solenoid, like in the picture below.

 

[ddalton]

Re: 95' 175hp won't take throttle with out primer

Tashasdaddy - thanks for the input. I left out an important piece in my post so I made a change to it. But long story short if I hammer the throttle the engine will die straight away but if I throttle up gently the engine will flatten out but continue to run. If I hit the primer for a second or two the rpms come up, hammer the throttle and we're on plane.

Checked all of the fuel lines doesn't appear to be a problem there. Thought about replacing them just to make sure. I'm pretty sure it's not a tank issue. Have two 10gal tanks, doesn't matter which one I'm using, same problem.

Thinking you're right, rebuild the carbs. I had read in another post that this particual engine was pretty bad about warping the float bowls. This may be the reason I'm seeing the light coat of oil on two of the carbs. If this is the case it could be leaking some air and making those two lean up.

re: clymer manual, thanks. I'll purchase an evinrude shop manual.

thanks again.

 

[jonesg]

Re: 95' 175hp won't take throttle with out primer

Its not hard to distort the carb bowl if the screws are over-tightened, the bowl seat area can be slightly dressed w/ fine sandpaper on a sheet of glass.

see the faq files on carb rebuilds, theres some instructional video on Youtube too. The hardest part is getting the carbs off the engine, but be religious about clearing the jets with wire, that sounds like the problem.

After its all done and reinstalled, clean bowls with tissue, pressurize the bulb and watch the seal area for weeping fuel.

 

[tashasdaddy]

Re: 95' 175hp won't take throttle with out primer

if it still acts up after carb rebuild, the OEM manual will have the correct link n sinc procedure for your particular motor. this sychronizes, the spark timing with the carbs, so that they work together at the proper time.

 

[ddalton]

Re: 95' 175hp won't take throttle with out primer

Rebuilt carbs, same problem. I paid particularly close attention to all small passages, orifices and jets in carbs and throttle body. Not to my surprise carbs were very clean inside, no varnish or other foreign material in bowls or anywhere else for that matter. I dressed the float bowls and the sides of the carb bodies with fine sandpaper and a piece of glass. All six were warped. I have 2 or 3 hours of lake time on carb rebuild and no fuel weeping so far.

I did find #40 Intermediate air bleed orifices in the carbs. The Parts Catalog calls for a #39's in the 175GLEOM engine. Doubtful that this was the cause of our problem but I replaced the #40's with #39's, not noticable change.

Questions:
1) Smaller intermedate air bleed orfices creates a richer mixture, correct?

2) What should the compression be for this engine? From what I gathered from my Evinrude service manual the biggest factor in being able to properly tune an outboard is there should be no more than 15 psi difference between cylinders and if I understand correctly on a V block you compare averages between banks (starboard vs. port) Correct? BTW - My average difference between the two banks is 9psi. But what's considered low compression for this engine? My highest single cylinder reading was 105 (Starboard side), the lowest 89 (Port side). Others varied from 95 to 100.

3) Next step - Synch and Link - but I don't have the OMC Ignition Analyzer handy. Can a timing light attached to the number 1 cylinder be used in place of the OMC Ignition Analyzer to set Idle Timing and Max Spark Advance?


Thanks in advance for your suggestions and help.

dd

 

[ondarvr]

Re: 95' 175hp won't take throttle with out primer

To help get accurate answers we may need a little more info.

Is this motor new to you?

If you've owned it for a long time is this a new problem, or has it always done it?

Has the problem changed over time?

 

[jonesg]

Re: 95' 175hp won't take throttle with out primer

Rebuilt carbs, same problem. I paid particularly close attention to all small passages, orifices and jets in carbs and throttle body. Not to my surprise carbs were very clean inside, no varnish or other foreign material in bowls or anywhere else for that matter. I dressed the float bowls and the sides of the carb bodies with fine sandpaper and a piece of glass. All six were warped. I have 2 or 3 hours of lake time on carb rebuild and no fuel weeping so far.

I did find #40 Intermediate air bleed orifices in the carbs. The Parts Catalog calls for a #39's in the 175GLEOM engine. Doubtful that this was the cause of our problem but I replaced the #40's with #39's, not noticable change.

Questions:
1) Smaller intermedate air bleed orfices creates a richer mixture, correct?

2) What should the compression be for this engine? From what I gathered from my Evinrude service manual the biggest factor in being able to properly tune an outboard is there should be no more than 15 psi difference between cylinders and if I understand correctly on a V block you compare averages between banks (starboard vs. port) Correct? BTW - My average difference between the two banks is 9psi. But what's considered low compression for this engine? My highest single cylinder reading was 105 (Starboard side), the lowest 89 (Port side). Others varied from 95 to 100.

3) Next step - Synch and Link - but I don't have the OMC Ignition Analyzer handy. Can a timing light attached to the number 1 cylinder be used in place of the OMC Ignition Analyzer to set Idle Timing and Max Spark Advance?


Thanks in advance for your suggestions and help.

dd

hmm, you have the optical ignition right?

I think you need to make sure the ignition advance pickup roller is right at the cam, just touching the cam, see these photos.
The manual lacks these pictures .

http://bbcboards.zeroforum.com/zerothread/357667-throttle-roller-timing-arm-adjustment-60-motors

Also, if you have the CDI power pack you don't need the OMC analyser.
http://www.maxrules.com/fixomcoisignition.html

 

[ddalton]

Re: 95' 175hp won't take throttle with out primer

ddd

 

[ddalton]

Re: 95' 175hp won't take throttle with out primer

ddd

 

[ddalton]

Re: 95' 175hp won't take throttle with out primer

To help get accurate answers we may need a little more info.

Is this motor new to you?

If you've owned it for a long time is this a new problem, or has it always done it?

Has the problem changed over time?

ondarvr - thanks for the response.

I've had this boat and motor for about 2 years. Yes it has always done this to some extent but has gotten worse with time. But I can't help but think that some of that could be the result of me tinkering around trying to resolve the issue too.

I took it to the dealer I purchased it from and they diagnosed the problem as a bad power pack and timing sensor. But because they wanted $800 for the power pack, sensor, a set of plugs, and their labor to replace them I chose to purchase the parts and do it myself. I saved $500 but it didn't fix the problem.

 

[ddalton]

Re: 95' 175hp won't take throttle with out primer

hmm, you have the optical ignition right?

I think you need to make sure the ignition advance pickup roller is right at the cam, just touching the cam, see these photos.
The manual lacks these pictures .

http://bbcboards.zeroforum.com/zerothread/357667-throttle-roller-timing-arm-adjustment-60-motors

Also, if you have the CDI power pack you don't need the OMC analyser.
http://www.maxrules.com/fixomcoisignition.html

thanks for the feedback.

Yes we do have optical ignition but do not have CDI ignition, OMC. Which btw I recently replaced both power pack and timing sensor.

I have checked and adjusted the timing roller per the procedure in the Evinrude service manual. But please help me clarify something regarding that. The service manual says; "To verify adjustment, move linkage rearward and then forward. Timer base and carburetor linkage must begin to move at exactly the same time". The procedure in your Internet link doesn't describe the position of the throttle cam and cam roller in relation to the spark lever roller. So if adjusted where the throttle cam was in a netural postion (not touching the throttle cam follower) the spark lever would / could potentionally be adjusted so it would advance 1/4" inch or more before the carburetor linkage begins to move. (Whew..... hope that makes sense.)

dd

 

[Fl_Richard]

Re: 95' 175hp won't take throttle with out primer

All of them need to begin to move at the exact time. As the throttle roller comes off idle the throttle plates and advance need to all start moving at the same time.
If throttle moves first followed by advance than the timing will be off throughout the range. If the advance is forward of the throttle the same applies.

You'll know it's right when you see it.

And the OIS timing can be set with a timing light while the engine is running.

 

[ddalton]

Re: 95' 175hp won't take throttle with out primer

All of them need to begin to move at the exact time. As the throttle roller comes off idle the throttle plates and advance need to all start moving at the same time.
If throttle moves first followed by advance than the timing will be off throughout the range. If the advance is forward of the throttle the same applies.

You'll know it's right when you see it.

And the OIS timing can be set with a timing light while the engine is running.

Thanks for clarifing that. That's what the service manual says but books have been known to be wrong.

Checked and re-synch'd the throttle plates last night. They were ok but reset just to make sure.

Will test VRO2 next to see if I have a weak pump.

I'm curious; what symtoms do cracked or worn reed valves cause?

 

[jonesg]

Re: 95' 175hp won't take throttle with out primer

thanks for the feedback.

Yes we do have optical ignition but do not have CDI ignition, OMC. Which btw I recently replaced both power pack and timing sensor.

I have checked and adjusted the timing roller per the procedure in the Evinrude service manual. But please help me clarify something regarding that. The service manual says; "To verify adjustment, move linkage rearward and then forward. Timer base and carburetor linkage must begin to move at exactly the same time". The procedure in your Internet link doesn't describe the position of the throttle cam and cam roller in relation to the spark lever roller. So if adjusted where the throttle cam was in a netural postion (not touching the throttle cam follower) the spark lever would / could potentionally be adjusted so it would advance 1/4" inch or more before the carburetor linkage begins to move. (Whew..... hope that makes sense.)

dd

The proceedure assumes you have the throttle cam where it belongs.

The spark lever roller should not be more than 1/8th inch from the lever, ut will do nothing once beyond that point in terms of advancing spark.

Regardless how you are reading the manual, spark must move before fuel or there is no such thing as "advance".


Its very simple, pop the hood off, remove air box, place in neutral and push the throttle fwd. Watch the butterfly's in relation to the ignition advance on the flywheel. Ignition advances first.

Then it picks up the throttle cam and butterfly's start to open.
This is normal.

Now watch as it nears WOT, throttle cam stops and butterfly's are WOT.
But ignition keeps on advancing.
Imagine that.