25HP 1979 running issues

[capecodder]

Hello all I am stuck and don?t know what to do next. First off, thanks to everyone who contributes to this forum. I read this forum everyday as well as search for answers to my questions. I could not have gotten this far with out y?all.

1979 25HP 25RL79 which I resurrected from a 7 year hiatus. I used mystery oil in the cylinders.

I have:
Converted to short shaft
New water pump rebuild
Compression 118,120
Spark plug gap @.038 stalls, stays running @ .030 . spark jumps a ??
Cleaned and rebuilt carburetor.
New fuel lines
Cleaned fuel pump
New primer bulb and tank
Fuel ratio 50:1 1gallon:2.56oz.
Ignition coil continuity OK
Ignition coil ground OK

This motor is starting but runs rough and unless the plug gap is .030 it will not stay running. Visually the plugs are black carboned and very wet. This leads me to believe its running rich. Try to run it lean and it stalls then will not restart. Cant put it into gear to set the mixture cause it stalls. When its choked at start up it revs like the dickens then stalls when choke is put in. I remember when I was doing the carb clean/rebuild that when looking straight down at the high speed nozzle the small tube in the center of the nozzle was not in the center of the nozzle. It was pushed over to one side. Is this normal? Could that be an issue? The nozzle was not removed just carb cleaner and air.

Thanks
Rick

 

[wavrider]

Re: 25HP 1979 running issues

Your spark is weak. should be 7/16 inch jump of spark.

Trouble shot your ignition system. powerpack. pickup coils need a good ohm meter to do this with also.

 

[ezeke]

Re: 25HP 1979 running issues

Hard to get that 7/16 on a rope start. Is that what you have?

Are you sure your choke is opening after you get it running?

How did you set your carburetor's slow speed needle?

The smaller tube is supposed to be to the side at the float bowl end.

 

[capecodder]

Re: 25HP 1979 running issues

ezeke wavrder

yes it is a rope a start. while I have not used a sparktester, to me it seems like a powerfull spark. I will check the pickup coil and power pack.

I just figured since the plugs are so wet and carbed up I had a fuel problem. At this point I am figuring its more than one issue here. I already took the pump off and secured it with nuts to see if it was leaking thru the hole. It was OK no fuel.

yes the choke is open I can see it thru the hole in the air cleaner. with it choked it revs very high then slowly drops down to nothing then stalls. as it revs high I open the choke . I have tried half way and full open. it will start without being choked but runs sluggish.

kindda figured that tube is suppose to be like that.

what is the correct SP gap for this engine? The manual I have convieniently leaves this year and hp out ??

 

[wavrider]

Re: 25HP 1979 running issues

Check out the frequently asked question section (faq)
read about carb adjustment and starting procedures.

running with choke on and dieing with choke off shows a lean condition, most likely need clean/rebuild carbs or adjust low speed adjustment if you have one or do both.

 

[capecodder]

Re: 25HP 1979 running issues

an update and a few questions

I have not checked the pickup coil yet. I did find a coil ground issue, during a recheck, which I fixed. I also have done a decarb with seafoam. That made a big improvement in the running of the motor. The spark gap is now set at .40 which I think is right for this motor.

I still do have a couple of issues which I could use some help with. First off, the second day of the decarb it started without being choked and with a half a*s pull of the rope. I was shocked. Only thing was when I pumped the bulb before starting, fuel came pouring out of the carb. I figure the float was stuck because of the cold 39'. Does anyone know why it would do this?

Also it has a bad misfire/backfire is with a huge puff of smoke. I would consider a miss. The motor jerks but does not die. Could this be the seafoam? Maybe carbon build up on the plugs causing misfire? coil?

Also the exhaust housing is filling with water but still circulating thru the motor, even a little spray thru the exhaust relief port ( 2 holes that resemble nostrils at the top of the housing) Is this ok? run in a barrel.

Thanks in advance for your help.

Rick

 

[ezeke]

Re: 25HP 1979 running issues

Start with float. The float valve needs to be connected to the float arm with a clip. If it did not come with the kit, you still need to find one. It is important to stop that fuel overflow - too dangerous. Some of the old floats get saturated and sink and that can be the problem.

"Also the exhaust housing is filling with water but still circulating thru the motor, even a little spray thru the exhaust relief port ( 2 holes that resemble nostrils at the top of the housing) Is this ok? run in a barrel."

Water exiting through the exhaust relief is normal and correct. It will increase under load on the water

 

[capecodder]

Re: 25HP 1979 running issues

thanks Zeke

It is a new float, clip and level...there is no doubt there is a problem there tho. I am gonna break down the carb again....no biggy. I just wondered if the cold temp maybe had something to do with the float issue. its march and I have been keeping it outside.
Any thoughts on the misfire problem during decarb. do you get a cough and smoke when this is done?

I am confused as to to fuel or electrical with this misfire. This motor had been sitting 7 years and wonder if the carbon build up was so bad that its building up on the plugs and weak fire until it blows off.

is ok do do a third ( 15min. )day of decarbing? will it hurt or wont hurt

Thanks

 

[wavrider]

Re: 25HP 1979 running issues

Sure do another de-carb.

I have sometimes had to run sea foam twice through to get all the crud carbon burned off. Just have another set of plugs to go in after de-carb as sometimes it fouls them.

The cold weather and floats? I do not think it should as duck hunters use the engines infreezing and below temps.

I believe you are on the right track, two issues, spark and fuel.
Fix the float problem as the needle should seal when carb bowl is full of fuel and not leak out. this will probaly solve your cough.

Get the spark tester to see what type of spark you are getting. You almosy got it going now. Good luck and let us know what you find.

 

[capecodder]

Re: 25HP 1979 running issues

I have recleaned this carb and found that the float may not have been as level as I thought.

My question . I have done 2@ 15min. runs with the seafoam decarb mixture. I still have some of this mixture left. is it OK to run this tank dry of this mixture? is too much of this decarb bad for the engine?
Thanks
Rick

 

[wavrider]

Re: 25HP 1979 running issues

no it will not hurt to decarb again.
Keep in mind this just helps clean the carbon out of the engine, still need to have carbs all cleaned good and all jets cleaned also.
De-carb does wonders for engines.
Have you checked your compression yet?