motor problems

[blackwidow]

HELP!!! my 86 28hp evinrude was running great, my water pump stopped working and over heated, after fixing now won't start. Happened to my brother few years back, said to replace the brain, Replaced the brain, new plugs, good spark from coils, plenty of gas, can't find a burnt wire, some suggested switching plug wires and coil wires from brain, no difference, turns over great and even sounds like it wants to start, back fires when I first try to start it. my brother said he also changed the sensor under the flywheel,I did but it was from an old motor. going back through today and solder all the places where there are but splices. I ordered a new sensor maybe it's that??? any ideas would be greatly appreacia

 

[F_R]

Hm-m-m-m-, I'm wondering why you are focusing on the ignition when it supposedly has good spark. Even if it did get hot enough to destroy the power pack (brain), if it got that hot the powerhead certainly is damaged. You have checked the compression, right??

 

[boobie]

What do you call good spark ??

 

[jakedaawg]

Compression test before spending any more $$$

 

[Tim Frank]

Compression test before spending any more $$$

^^^^ +1

And if you did not actually test to verify a problem with the "brain", don't throw the old "brain" away.

 

[Chinewalker]

Stop throwing parts at it until you've done a compression check! If it was severely overheated, you may be in for much more than ignition problems!

 

[blackwidow]

first thanks so much for you guys input. when I put a gauge on both cylinders it fluttered back and forth real fast????? although it was a home made one, I checked it on a tire first and it held.

 

[racerone]

You need a compression tester.------Not a home made gadget !

 

[blackwidow]

ok guys I listened to ya'll and did a compression test, 29 psi on both cylinders. Blown head gasket??? should I start there? and if so what is the torque on the bolts? thanks for any help

 

[flyingscott]

Get the head off and see if it is only the head gasket. Could be scored pistons.