Chonda Engine Tuning

Forum for LO206 & Chonda classes

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Robert Schneider
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Re: Chonda Engine Tuning

Post by Robert Schneider » Tue Aug 19, 2014 6:14 pm

Rob Brown wrote:I can't make it that quickly. I still need change my main seal and figure out if its my valve seals that are leaking causing smoking. Plus I don't have all those jets nor could I get them soon enough. Oh well guess I miss out...
Are you running a blue plate or no plate? Is the main seal leaking oil? When is engine smoking? At idle or up in the rpm range? What jets do you have? I have extra valve seals and some extra jets. I am planning on removing the heads on multiple karts to clean up the valve seats so it would be no problem at all to stick new valve seals at the same time.

Robert Schneider
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Re: Chonda Engine Tuning

Post by Robert Schneider » Tue Aug 19, 2014 6:15 pm

Barry Peel wrote:I will be there. I do have 15/55 gearing and new spark plug. I don't have any 6 degree key or head gaskets. Can I purchase from you guys?
I will be bringing a number of head gaskets with me so I'll reserve one for you. I also have an extra 6 degree key that I'll hold for you as well.

Robert Schneider
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Re: Chonda Engine Tuning

Post by Robert Schneider » Tue Aug 19, 2014 6:19 pm

Scott Lytle wrote:Rob, this sounds like a great learning opportunity that I will make time for. What time does it start on Saturday?
I'm planning on getting there at 9:30. Mark will be coming out to help with the repairs and tuning as well. I'll post a plan of attack for the day tomorrow so you guys know more specifically what to expect. Plan on spending at least a few hours at the track to complete all repairs and tune the engine.

Robert Schneider
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Re: Chonda Engine Tuning

Post by Robert Schneider » Tue Aug 19, 2014 6:22 pm

Charles Borsos wrote:Robert, this is a great initiative. Wish we could make it out but have a family commitment. Hope to see you all at the track on the Sept 7! Charles
Ill be documenting all the repairs and adjustments made so anyone that misses this Saturday will still be able to get some help.

Rob Brown
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Re: Chonda Engine Tuning

Post by Rob Brown » Wed Aug 20, 2014 5:50 am

Robert Schneider wrote:
Rob Brown wrote:I can't make it that quickly. I still need change my main seal and figure out if its my valve seals that are leaking causing smoking. Plus I don't have all those jets nor could I get them soon enough. Oh well guess I miss out...
Are you running a blue plate or no plate? Is the main seal leaking oil? When is engine smoking? At idle or up in the rpm range? What jets do you have? I have extra valve seals and some extra jets. I am planning on removing the heads on multiple karts to clean up the valve seats so it would be no problem at all to stick new valve seals at the same time.

Blue plate, drive side bearing is leaking. I have the new seals just need to do it. Smoking at idle mostly. I think its bad valve stem seals, I have new ones of those as well. Im going to try and make it. Getting the kart back to the house tonight.

Robert Schneider
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Re: Chonda Engine Tuning

Post by Robert Schneider » Thu Aug 21, 2014 8:56 am

General plan for the Chonda Tuning Session on Saturday:

I'll arrive by 9:30 and run 10-15 laps in my kart to see how fast I can run on saturday and everyone can use this as a guide for how their kart is running.(The track is much slower on non race days due to less rubber deposition on the track surface) Mark will arrive around this time as well. He will be helping with tuning everyones engine.

As soon as each person arrives, before you start your engine, I need to set your valves to .004" intake and .008" exhaust. This has to be done with the engine cold. Then you will need to run 10-15 laps to see how your setup is working before we fix it up. Be sure to tell me your fastest lap time so I can record it.

After you have run some laps and your engine temperature has fallen to 190 deg F, I will perform a leak down test on your engine. If the leak down test yields results between 2% and 3% we will move on to setting the timing. If the results are higher than 2%-3% we will pull the head off of your engine and lap the valves which will make them seal better. After lapping the valves we will put the head back on the engine, set the valve clearances to .004" intake and .008" exhaust and then perform the leak down test again. A new spark plug will be installed at this time as well.

To set the timing we will install the appropriate key to achieve 26 deg.(the spark plug will fire when the angle of the crankshaft is 26deg before the piston reaches the top of the compression stroke,TDC) The actual timing will then be verified using a piston stop and a timing light.

If the 55 tooth rear gear has not been installed yet, we will do that too.

We will then move on to tuning the carburetor by first installing what I estimate to be the correct jet for the weather conditions on Saturday. It will most likely be a .039" jet for blue plate engines, .040" jet for purple plate engines and .038" for unrestricted engines. We will also set your idle mixture screw to 3.5 turns out from the bottom.

Next you will run another 10-15 laps to see how much your lap times have improved. You will need to keep a close watch on your engine temperatures and make sure the temp never goes above 450deg but levels out around 430deg around lap 6. If you engine fails either of these two criteria, bring the kart back in immediately to change the jet size. Running the kart with the temps above 450 deg F puts it at risk of damaging the engine. I will also run another 10-15 laps to see if the track times have dropped due to the increased rubber on the track and higher ambient temperatures. I will record all the lap times and repairs made so we will be able to see how the repairs and tuning relate to the lap time improvements.

The current list of people attending as well as parts I'm bringing for them is:

Ted
Stacy
Aubrey
Rob: extra jets, head gasket
Barry: 6deg key, head gasket
Sarin: spark plug, 6 deg key, 55t gear
Scott/Bryce

Let me know if im missing anything on this list. You can send me a PM. And if you'd like any clarification or more detail about the plan for Saturday, post here on the forum and I'll post a response for everyone to read/learn.

Robert

Rob Brown
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Re: Chonda Engine Tuning

Post by Rob Brown » Thu Aug 21, 2014 10:00 am

I have an extra head gasket and a couple of jets. DOnt recall exact sizes on the jets off the top of my head.

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Ted Dziedzic
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Re: Chonda Engine Tuning

Post by Ted Dziedzic » Thu Aug 21, 2014 11:19 am

There is a chance I will need the 6 degree key. Depends on our "Grand" postal service.

Rob Brown
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Re: Chonda Engine Tuning

Post by Rob Brown » Thu Aug 21, 2014 11:42 am

Yeah, I think I only have an 8 and whatever came on the engine with the steel flywheel...

Robert Schneider
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Re: Chonda Engine Tuning

Post by Robert Schneider » Thu Aug 21, 2014 2:40 pm

No problem, I'll bring some extra 6deg keys.

Robert Schneider
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Re: Chonda Engine Tuning

Post by Robert Schneider » Fri Aug 22, 2014 12:41 pm

One more thing to bring with you are rags or paper towels and brake or carb cleaner to clean off the dirt and oil from the head and engine before we reassemble it.

Richard Mortensen
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Re: Chonda Engine Tuning

Post by Richard Mortensen » Fri Aug 22, 2014 1:32 pm

I'll be coming out to join you Robert. I'll have the 55 gear on. I'm running the blue restrictor, but only have the stock 38 jet.
I'll be the least mechnically minded guy out there!!
Thanks for your generousity!
Richard

Scott Lytle
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Re: Chonda Engine Tuning

Post by Scott Lytle » Fri Aug 22, 2014 2:32 pm

Does anyone have a local source for the racing spark plugs? I've called every 'major' parts store in northwest Houston and haven't found anyone that carries the AR3910x racing plugs.
Thanks.
Scott

Robert Schneider
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Re: Chonda Engine Tuning

Post by Robert Schneider » Fri Aug 22, 2014 2:33 pm

Richard Mortensen wrote:I'll be coming out to join you Robert. I'll have the 55 gear on. I'm running the blue restrictor, but only have the stock 38 jet.
I'll be the least mechnically minded guy out there!!
Thanks for your generousity!
Richard
Sounds good, do need a 6 degree key to set your timing? I'm getting ready to make a few...

Robert Schneider
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Re: Chonda Engine Tuning

Post by Robert Schneider » Fri Aug 22, 2014 2:37 pm

Scott Lytle wrote:Does anyone have a local source for the racing spark plugs? I've called every 'major' parts store in northwest Houston and haven't found anyone that carries the AR3910x racing plugs.
Thanks.
Scott
Don't worry about it, I have some extras. Also you can get them from Oreilly auto, but they usually take a day to come in.

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