hello.. I've had some problems with my streight 6 engines.. Well not the engines but maybe the carbs. Distributor caps were cleaned. One carb was cleaned.. New batteries.. . The port engine starts to backfire and loose rpms at around 1500.. I messed with the high speed intahe valve and the low idle. It starts and runs great but getting up over 1500 it starts to sputter slight backfire. Had em running good when I first put it in the water. I could run both engines at 2500 rpms with no problem. In neutral I can get the rpms up just fine but now when it's in gear. I have changed the fuel filters three times.. any thoughts? Sugestions? or better yet anyone know a good mechanic in the chicago area I can get to take a look at them.. ?? thanks!
the points froze up. I have that taken care of but still not able to get it the maintain the rpms. .. But no I haven't checked them. Sugestions on what to look for?
Hi, You mention changing your Fuel filters 3 times. Were they full of crud when you changed them? Do your engines have a vacuum advance mechanism? If so check this is working.
I'm not sure what a vacum advance system is? I can check the mannuals tomorrow. if I do have them what and how do I check they are working?
dont forget fuel pump I replaced both fuel pumps on mine four years ago and one has already gone bad, vent blowing gas. I am now trying to decide if it is the ethanol, I took it apart and it was dryrotted way to soon. If your pump is not keeping up because of rubber rot it would do something similar. Put a gauge on it and watch as you increase RPMs, it should maintian pressure.
Greetings t2, Oh my goodness...Hercules flat head 6's...We had two (MRL and MRLO for 12 yeaRS,) To the best of my memory, no vacuum advance. Springs ONLY control the ignition advance and it does sound like your problem is ignition. Try to find an OLD auto shop with distributor set-up equipment. They should be able to set advance angles (based on weight throw out data) for your distributor. I refer you to... http://www.classicboatwork.com/manuals/Instructions and Parts ML MBL.pdf for for carb' adjustment (if mod's allow). Pretty simple and robust engines. Hope this helps... Peter
hey guys thanks for the response. I'm heading out tomorrow to change the distributor caps to HEI. And replace the plugs. I'm almost 100% sure that this is the problem.. I'll keep you updated on the outcome.