Engine temps, general tuning help needed.

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olds97_lss

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I was out beating the crap out of my savage yesterday and I was getting temp reading around 220-230 at or near the glowplug down inside the head. The top of the head read 170 and the side of the crank case read 180-190, but the exhaust header read 250-370.

When the temp at the glowplug was around 250, it was acting as though it was lean. On a WOT jab of the throttle, it would almost stall. I'd richen it 1/8th turn, then it would be blubbery unless I kept running it hard. For normal putting around and climbing, it was kind of a headache. Which is why I beat the crap out of it. It ran good when ran hard and the temps stayed around 240-250 at the GP.

I'm kind of wondering if it has something to do with my air filter, the blubberyness at midrange. I took the filter off and cleaned it, but I replaced it with a motor saver filter I had laying around that I've never ran. It came with a trade that I had done about 6 months ago. I haven't run it with the MS filter yet. The filter I had on it came with an OS 21 RG.

In general, with this engine, I've not had a reall successful time tuning it. It's the Omega 21 Comp pullstart. When it runs well, it's a pretty good performer. But there's always a little blubber from about 1/3-2/3 throttle. And the weird temp readings I got above kind of threw me.

Anyone have any suggestions on how I can make it through a few hours without a headache with this thing? The XTM 24.7 is looking better all the time... My OS 21 RG in my maxx is really reliable, but it's not a high HP engine, so I don't want to get another one and throw it in my savage. But I would like to get the omega running right.

The Omega has about 3 gallons run through it. I've completely tore it apart, cleaned and sealed the carb, HS needle and backplate about 1/2 gallon ago. I've done that about 3 times on this engine. There's still a lot of pinch left in it as well. I run MHP 20% fuel with an OS #8 plug. I've also checked the fuel tank for leaks and replaced all fuel line (many times).
 
have you tried using a different carb? why not try putting you OS carb on it temporarily to see if it behaves differently? otherwise id say run it a hair rich and live with blubbery. it could be a rich LSN too. try that blubbery HSN setting and lean out the low end just a bit. if the LSN is too rich you can get too much fuel in the crankcase at low speeds that would take a while to clear out and appear that the HSN is rich on short bursts.

oh, and dont worry about exhaust temps. the only temp that matters is at the GP
 
For the temps, that's what I thought, but it kind of freaked me out anyway.

I already thought about using the OS carb, but it's about 1.5mm to big. Although, a friend of mine gave me his old trashed OS 21's so I could try the carb swap thing and he said take a dremel to the stupid thing and see what happens...

I have been dealing with the blubbery midrange. It's not as noticable if I don't let it sit at all and keep on the gas. I tried leaning out the low end a little, but then my temps shot up and it wouldn't idle down. It think it's about as lean as I'm going to get it.

ADDED at 3PM:
Well, I took the OS carb body, took everything out of it (needles, screws, throttle barrol...) then I ran a bolt through it with a washer on each end and tightened a nut down on the bolt. I then stuck the bolt in my dremel... kind of made my own lathe. Then I held it against a file and shaved off what I needed to get it to fit. It's now curing and waiting to see if it will work. Since I didn't get it perfect, I had to seal the neck up with RTV, but it's damn close.

ADDED AT 5:30PM:
Well, I couldn't wait... I just took it out for one tank. I'm home with a sinus and lung virus... stupid cold, so I snuck out with it (my wife was kind of bitchy since I'm sick). I ran one tank and after some needle adjusting, it rocked!

It's kind of hard to tell how well the variant temp problem will be since it's only 50 degrees F out. But damn!, I couldn't keep the front wheels down! It was running at 190 as well. That was the highest the temps got. And the mid-range blubber appears to be gone. I'll know better when I get un-sick and have some time to run more fuel through it.

Now that I got the exhaust gasket problem fixed, a cvd problem fixed (pins kept falling out) and now hopefully the stupid engine running... where was I going with that??? Oh yeah, Now I can actually have some fun!

CorradoPsi, Thanks for reminding me about the carb.
 
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