K5.9 break in

[jimc]

HPI rebuilt my motor,for free. So it's break in time. I am following HPI's method, 3 tanks idling on the bench, two in circles on the ground at max half throttle. I know there are many supporters of the heat cycle method but seeing as it's cold here in NY I am doing the first 3 tanks in my large heated garage. I will wait for warmer weather to finish breakin outside. It is difficult to judge exhaust smoke at idle on bench, the HSN is flush from factory and I richened it slightly. My question is how much unburned fuel/oil should be spraying from pipe? I am getting plenty, finger tip held one inch from exhaust for 1-2 seconds is covered with lube. Next question, OWB needs cleaned after every tank or it just slips. I ordered a new one but it came in wrong, so for now I must clean. I must say I have become pretty quick at that whole operation. The slipping if I am correct is caused by lube in the bearing, hence cleaning it allows it to grip again. I clean it with carb cleaner which obviously cleans it to complete dryness/lack of any lube. My question is, Should it be put back in completely dry or slightly lubed? I have been going with dry but wondering if thats bad for it. Thanks fellas. Jim C

 

[MudSlinger33]

The heat cycle break in is the way to go. Unlike other break in processes which involve idling through tanks, which some believe is hard on an engine do too low heat and a very rich mixture. Heat cycle brings the engine up too operating temps, allowing the engine components to move freely. It sounds like you may have been a little rich during break in, you shouldn't need to further richen from factory settings. This may also be the reason for your slipping OWB.

 

[jimc]

I am having some trouble. I ran three tanks through on bench and all went smoothly. Engine started easily and idled fine and maintained a temp of 225. Tank 4 and 5 on ground doing 1/2 speed runs and circles while maintaining temps between 200 - 250. Here's the prob, The motor does not want to open up past half throttle, idles fine and punches off line real snappy but bogs and stalls at the halfway point. Continues to do this regardless of carb settings. Reset to factory and made many attempts while adjusting richer, leaner etc.. Fuel supply seems fine, no air leaks in engine, lines, tank. Do I need to mess with the mid speed mix? I tried that also as I was running out of options but to no avail so I set it back to it's start point. I looked back at all the tuning threads I could find but seems like I have covered it all. WTF, help.

 

[Metalhead Matt]

Sounds the the tank isn't building pressure correctly or your lean on the hsn.

 

[jimc]

Seems like it was too rich. Went out today and ran a tank. Got her up to 240's and started to lean out a little at a time. Seems I was overly rich to begin with as there is a fine line on the HSN to base it flush against. Made sure to start flush and leaned it out about a full turn and it came alive. Seems to still be plenty of smoke. Definately not easy when it's cold out, windy too, so a little difficult to judge smoke

 

[2revo1maxx]

The most ideal situation is to run as rich as possible, while maintaining roughly 200 degrees. Vary the rpm and do it with the engine in the truck, on ashpalt, hard dirt, or concrete. No wide open runs! Pre-heat the engine to about 150 degrees then shut it down after about 5 minutes of run time. repeat the process several times. Always remember to put the piston at bottom when you shut it off.

 

[JessF]

it took a while to get my k5.9 started. Factory settings were super rich.

Have you sealed this rebuilt engine?

 

[liquidcool]

i had the same problem that jimc has or had. My problem was the main bearing was leaking. Jim did or do you have a lot of crud(oil and dirt) build up under the engine?