1973 1150 115 hp 2 stroke 6cyl

[hornetracing65]

Hello there, I recently came upon this old thunderbolt 115 hp motor and my son and I have taken it on as a project. All cyl have decent compression, motor turns over, carbs are getting fuel, but no fire. I will be testing the spark shortly, however I had another concern. My son pointed out that the power lead to the battery was getting extremely hot. Any idea to why this would be happening. Any help would greatly be appreciated. If we get this motor running well, my son will get to have a boat of his own he is very excited at 16. Again thank you for any help you can provide.

 

[emckelvy]

Any electrical part in the starting circuit that gets really hot is a sign of a poor connection at that point. Check your battery terminals and connections at the motor for cleanliness and tightness. You may even have a bad (corroded, etc) spot in the battery cable.

If you were doing a lot of cranking during the compression check, it's possible the cable got hot just from current passing thru. But you also want to make sure nothing is shorting out, either. So, if the battery cable sparks when you disconnect it, and nothing is turned on, that's a problem, too.

Here's some good info on checking CDI ignitions:

http://issuu.com/cdielectronics/doc...t.xml&backgroundColor=000000&showFlipBtn=true

Note that the CDI switchbox has a source of constant +12V connected to the Stbd side of the switchbox (Red terminal), and switched power to the white terminal on the same side. You can check that both terminals are powered-up when the key is in the ON position.

Common problem on these is a bad trigger, which requires removal and complete disassembly of the distributor to fix. CDI Electronics has replacement trigger housings available but they ain't cheap. Sometimes you can find a cheap parts motor on Craigslist with a good distributor.

HTH & G'luck......ed

 

[Chris1956]

Another common problem is that the engine wiring harnesses rot out by this time. Look for insulation that has fallen off the wires. Make sure the quick disconnect plug makes proper contact.