Spring Nats 2016

posted Jun 6, 2016, 9:17 AM by Scoob Edoo

The adventure started ten days before we left when I cracked my cylinder at the Bristol Match (Math) Tour.  Apparently I hadn’t fully tightened the nuts after I replaced the cylinder jug over the winter and during my runs it got progressively looser until it cracked and spewed water all over me.  Oops.  So I sought a mod Honda to buy in time for Spring Nats and found Carter Thompson’s for sale.  I made plans to stop by his house on the way to Nebraska with the plan to install in paddock before the Pro started.  It was a good plan.

We made it to his house and picked up the motor and continued on to Lincoln with no issues.  On Thursday I took Kieran to the airpark and got busy getting the motor ready to go on the kart.  I had to fab a header mount since mine was still on the old motor at home, but I pretty much had everything else I needed.  I got it mounted and started on the stand that day, but it didn’t sound quite right so I focused on jetting and thought I had it OK for the Pro.

Friday morning runs were pretty bad – had no launch and then every time I came off the throttle the motor just fell flat, like it was way too rich.  Then just before my 4th run the clutch cable slipped and I stalled.  So back to paddock I went to work on the jetting (I thought).  No matter what I did – changing the pilot from 60 to 55 and then to 52, along with main jet from 185 to 170 – the motor just ran like crap.  Over the next days we checked everything and tried changing ignition components, grounds, stator, carbs, plugs, fuel pumps to no avail, eventually settling on probably bad fuel.  I ran to the VP station and got their last can of C12 2 minutes before closing, thinking that would work for the next day.

In the morning the motor sounded better but I could tell it still wasn’t OK so I drove Jamie Yost’s kart in the last session.  The kart needed some setup help to tame it some so I helped with that.  She then got into the Bonus challenge and broke out in a BIG way, winning the first round by something like 7 seconds which killed her chances for the second round where she lost by 4+ seconds.  But the kart sounded and looked better after that.

Meanwhile the saga with the new motor continued.  I thought the new fuel and further adjustment to the jetting fixed the problem.  However, the first run of the Tour showed that it wasn’t fixed still.  Every time I even hinted at coming off throttle the motor fell flat and chugged as if it were drowning in fuel.  So I went and helped Kieran instead of taking the other two runs.

In the afternoon, without much else to do I went extreme on jetting, going to a 48 pilot with the 170 main and then the motor sounded MUCH better.  I took a few runs on the other side of paddock to see how it felt and thought I’d gotten to the heart of the matter for Monday’s runs.  SO I went to dinner with the family thinking Monday was going to be the day I was waiting for.

Monday’s conditions were similar to Sunday’s so I left the jetting as it was and immediately found that the same thing was happening again, but I could control it a bit better by not coming off throttle so abruptly.  By my last run of the weekend I was only 2+ seconds off the pace, but clearly there was still something wrong.  My best guess now is that the pump-around modification to the carb is failing and air is getting into the carb, making it run too lean and thus flooding when coming off throttle abruptly.  All of the external sealing compound that CKT put at the tube junction has broken up and fallen off so until they tell me differently I’m going with that as the problem.  I was definitely not fuel or ignition or grounding so the choices are slim beyond the carb.

Kieran was frustrated at being crushed by Riley by a few seconds on each course during the weekend so I gave him a good pep-talk before his last run and he dropped down much closer to where he should be and was happier – but his clutch bearing seized as he came off course to get his time and get weighed.  It was the needle bearing at the sprocket that seized and I replaced it this last weekend to get ready for another event at Bristol (but weather precluded our running the karts at that one).

But my continuing adventure didn’t stop there!  We left early on Tuesday for the marathon drive home and about 90 min in the dash battery/alternator light came on and stayed.  I watched it for awhile and realized that the alternator must have failed.  We made a beeline for the “nearest” Walmart – in Leavenworth, KS – to get it checked.  They tested the batteries and found that the new one from January has been damaged by the older battery (remember kids, always replace diesel trucks’ batteries in pairs) so they both needed replaced.  The new one was completely covered under the warranty but the other one was not, so I bought a new one and told the guy to check the status of the alternator.  After 2.5 hours we were back on the road, but the battery/alt light came on again so we turned off the AC, radio, and DVD players and drove like crazy trying to make it home..

Unfortunately, it became obvious that there was no way we’d make it home since the headlights would seriously drain the remaining battery life quickly, so I made alternate plans to stay in Clarksville, TN (same hotel as we’d stayed on the way out) and talked to one of the local AutoZone’s about the alternator since mine had a lifetime warranty.  They had one and I put that address in the GPS and hoped we’d make it before we needed headlights.  We did, but just.  It was getting to be duck when we hit the exit.  I watched the battery meter as I hit the brakes on the exit and the drain was substantial.  The electrical system was so down on juice that the AZ guy couldn’t measure the output to determine if the alternator was dead (hmmm, let me think about that for a minute).  So I bought a replacement alternator to swap in the morning and said I’d bring the dead one back in the morning, assuming I could get the truck started.  And then we headed to the hotel to sleep.

In the morning, after a very good deep sleep I took Rhys out and let him roam while I got my tools and swapped the alt.  No muss and no fuss.  After ~20 min I went to start the truck and it had enough juice and enough warmth from the previous day to turn over and fire.  I left it running while we ate breakfast and got ready.  We had AC and DVDs for the 4.5 hours home and the batteries have no apparent ill effects from being that drained.

So after that adventure I put on my PWK carb from the other motor to see if that would run better (jetting was from Bristol three weeks before so should be pretty close) and it sounded MUCH better than it did in Lincoln on the stand so maybe that will work while I get the other carb and motor evaluated and fixed.

Not sure when the next event is, but it likely won’t be until after TKD National Championships in FL over the July 4th week.

Comments