2.6 xp Overheat at idle and wont rev up

[Jho928]

Hi I have a 2.6 xp (basically a hopped up 235 crossflow) 1984 After idling in gear for a while the overheat horn sounds if I jump on it and get on plane after a minute or so It goes off. I have 2 new thermos installed (143 deg) and a new impeller. At idle a have little water pressure > 3psi at 3000 rpm I have 12-15 psi and at wot I have 20 psi. I was gonna pull the thermos and check them but they are new. Also after a while the motor will not rev up in gear it boggs out. I don't think it is a carb issue cause it comes and goes. I am thinking maybe after idling for a period in gear the plugs are fouling . This happen today and after letting it sit for a half hour I got it to go by feathering throttle .It will start and rev fine in nuetral. Any ideas I am using L77jc4 plugs. Can fouled plugs cause this ?
I Need old Crossflow 235 gurus. Thanks Jim
I was running bosh plugs in this last year Im gonna dig them up and put them back in

 

[Jho928]

Re: 2.6 xp Overheat at idle and wont rev up

Hi I have a 2.6 xp (basically a hopped up 235 crossflow) 1984 After idling in gear for a while the overheat horn sounds if I jump on it and get on plane after a minute or so It goes off. I have 2 new thermos installed (143 deg) and a new impeller. At idle a have little water pressure > 3psi at 3000 rpm I have 12-15 psi and at wot I have 20 psi. I was gonna pull the thermos and check them but they are new. Also after a while the motor will not rev up in gear it boggs out. I don't think it is a carb issue cause it comes and goes. I am thinking maybe after idling for a period in gear the plugs are fouling . This happen today and after letting it sit for a half hour I got it to go by feathering throttle .It will start and rev fine in nuetral. Any ideas I am using L77jc4 plugs. Can fouled plugs cause this ?
I Need old Crossflow 235 gurus. Thanks Jim
I was running bosh plugs in this last year Im gonna dig them up and put them back in

Bump

 

[Jho928]

Re: 2.6 xp Overheat at idle and wont rev up

Bump

Does anyone know if this motor has S.L.O.W feature (it is a 1984 e235stlcrc)
Thanks

 

[emdsapmgr]

Re: 2.6 xp Overheat at idle and wont rev up

The engine has the old dual power packs and does not have SLOW. Your water pump should pump between 4-6 lbs at idle, so your idle pressure is slightly low. Around 20 lbs at WOT is normal. Run the normal factory Champion plugs in that engine: UL77V. At dead idle all your cooling runs through each thermostat. The pressure relief valves are closed. If your stats are new and fucntioning, then you can have other cooling issues. The following can be checked: 1. pull the head covers off the heads and check for any debris inside them. 2. Pull the heads off and check for the placement and condition of the rubber water diverters by each cylinder. They can get out of location and debris tends to collect by them. Also check the passages around each cyl to make sure waterflow is unimpeded. You should be looking for salt deposits (if a saltwater engine) sand or weeds. Does your hot horn work-have you tested to be sure the horn works? Possible your engine is slowing down due to an impending overheat lockup of the rotating assembly. You can easily check for cyl head temps by using/renting a laser temp gun. Engine should idle at 143-154 degrees. When on plane, the pressure relief valves will open and the engine head temps will go down-significantly.

 

[Jho928]

Re: 2.6 xp Overheat at idle and wont rev up

I will check out the internals of the heads. Horn is functioning. Thank for the reply.