Author Topic: Temp Readings?? Tuning questions?  (Read 1896 times)

cruz01

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Temp Readings?? Tuning questions?
« on: November 12, 2007, 09:19:16 AM »
Hey Guys. New to the site... Well I recently purchased my very own 350 and it's amazing what will happen when someone leaves an odyssey outside for three years to rot... Anyway, I've been trying to replace a lot of worn stuff and now its running pretty good but I'm having a little bit of a hard time tuning it.

I purchased a used digatron gauge but the temp gauge reads by the probe connecting around the spark plug, not an egt probe. I finally ran my odyssey for the first time and I noticed that the gauge was reading around 250-340 degrees at the cylinder head. Where should it be at? I rode it in Gorman, Ca which is at about 3,000 ft. and it was about 48 degrees outside if this helps..

Also, I noticed that the top end speed was a little off. It seemed like it struggled to run at full throttle. Oh, by the way, the cylinder compression is reading at about 128 psi. I rebuilt the carb, which is a stock Keihn, and I set the air screw at 1-1-2 turns out with the needle set at the 3rd groove. It has new fuel lines, new fuel filter, new check valve and the fuel pump seems to be working good. The reed valve seem a little worn which I am going to replace and I noticed that the intake boot has a little crack on the top. Would that be my problem? Any suggestions would be great!!!

cruz01

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Temp Readings?? Tuning questions?
« Reply #1 on: November 15, 2007, 08:39:16 PM »
Tough crowd in here.. Well, let me ask someone this, is my gauge reading accurately? The gauge that I have is a Dibatron DT-32. The temp sensor goes to the spark plug instead of a EGT probe. After riding my odyssey for the first time, the temp was getting up over 310 degrees. Is this right or do I have a serious problem?? Also, I was running at about 20:1 ratio. From reading other forums, I realize this is running pretty high. Anyone's help or advice would be really appreciated... Thanks

Moskito

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Temp Readings?? Tuning questions?
« Reply #2 on: November 16, 2007, 05:44:09 AM »
Tough crowd - HA!!   pretty good.

Let's see...

Digatron.  You're using a cylinder head temp setup.  Sorry, I have no experience with those - always used the EGT probe - so I can't tell you what sort of temps you should be seeing.

Reeds - worn = bad.  Replace them (I see you're doing that)

Cracked intake  BAD!  Air leak city.  These things can cause you all sorts of problems - including a run away engine that destroys itself.

The best thing to do with jetting is first get the reeds and intake replaced and then start doing plug readings.  Once you get the plug readings dialed in then start paying attention to the Digitron and make note of where it seems to run once the engine's tuned.  They're a great instrument to use to make sure the engine's running correctly, but the first time of tuning needs to be done the old fashioned, pain in the butt way.

Switch to 32:1 on the oil ratio too - 16 oz to 4 gallons.  (I always ran 40:1 - 16 oz to 5 gallons).  Don't use Wally World type oils - use a good quality two smoke oil like Maxima, Yamalube or Spectro.

How's the air filter?  Don't wash it with gasoline - that destroys them.  Use Simple Green or a filter cleaning solution and follow the instructions.  Don't over-oil the filter either.  Coat it with a spray on filter oil until the whole thing's covered, then work the oil into the filter by squeezing - don't wring it.  Once you're done with that, wrap it with a paper towel and then squeeze it again.

Top end speed - is the vehicle just going flat on top end or is it struggling to get there?

Here's a link on how to jet your carb.

Thanks Dennis - I fixed it.
Moskito - Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming \'WOW-What a Ride!\'

FL670R

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Temp Readings?? Tuning questions?
« Reply #3 on: November 16, 2007, 08:42:07 AM »
Slight typo above
??  32:1  =  20oz Oil to 5gal of gas
??  40:1  =  16oz Oil to 5gal of gas

cruz01

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Temp Readings?? Tuning questions?
« Reply #4 on: November 16, 2007, 02:04:34 PM »
I installed a new UNI filter and used the spray oil that goes with the filter.

As far as the top end goes, it bogs or hesitates to run at full power. I figured it could be a jetting adjustment but faulty reeds and and an air leak could be the problem. The carb is a stock Keihn and I completely rebuilt it so I know that there's nothing clogged in the jets. According to the Honda Manual, it says that the air screw should be preset at 1-1/2 turns out. That's were I set it at. Is that were I'm going to be doing most of my adjusting as well as checking the plug?? Keep in mind Moskito I was also running at a 20:1 ratio. I don't know if that will play a factor in tuning the oddy properly. Thanks for your help moskito......

Weed

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Temp Readings?? Tuning questions?
« Reply #5 on: November 17, 2007, 09:32:39 AM »
First off if your boot has a crack.....you are going to melt her down.  I have several here that are used but in excellent condition.  I'll sell them $15 plus shipping.

The Digatron is the best investment you have for that machine!!!!!  The head temp of 310 is OK.  I have had them up to 410 degrees.  If you stay below 350 you will be fine.  I would recommend you change it out for an EGT probe.  Email me and I can help you get one.

It is probably bogging on the top end because it can't get enough air.  Do you have the air box lid on it?  and has it been modified?

The compression is OK....128psi is fine...

I would also recommend you go with 32:1 or 40:1.....like Moskito has suggested.  

I run 50:1 full synthetic Bel-Ray MC1 in my built Silver Bullet Ody.... Todays oils are soooo much better than they were 20 years ago.

Yamalube, Spectro, Amsoil, Belray, Honda, Maxima....all great oils.....oil for weed eaters, leaf blowers or your chainsaw should be OFF LIMITS....don't use that cheap crap.

sales@pilotodysseyperformance.com

cruz01

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Temp Readings?? Tuning questions?
« Reply #6 on: November 17, 2007, 11:54:55 AM »
Weed,

The air filter box is oem with a new uni filter. What to do if air is being too restricted? Its only the top end that's bogging a little. Mid and low range is quick and responsive. I'll email you about getting an egt type gauge.