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883 to 1200 conversion gone bad???

DavesKystoms said:
And yes VOES is the sole means of advance. At a steady rpm no load is where I've tested this for now. With fuel injected engines you wouldnt need your A/F meter, you should be able to look at the numbers on the PC. On carbed engines how are you installing your sensor? I have wideband A/F meters but for me to use these I would need to drill holes in my pipes and I'm not to excited about that. Shouldnt I be able to get it close without monitoring A/F?
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1) If VOES is your only advance & your total advance is 28 degrees, I would say timing should not be your problem.
2) To use your wide band sensor you will have to install bungs in the pipes. If you try to use the sensor at the end of the tail pipe you will run into all sorts of inaccurate measurements.
3) With FI you do need the a/f ratio meter because the VE tables are not synchronized to the A/F ratio map. The A/F ratio map is only the "desired" A/F ratio. It is not the actual ratio coming out the pipe.

What bothers me about your glow problem is you said you can increase the RPM above the glow RPM and it will stop glowing.
I don't know what the fix or problem is, but that part of it sure sounds strange. Even if the glow is normal, I would think it just would continue to glow as RPM was increased beyond the glow threshold point.. (?)
 
I know that i would need to install bungs and thats what I'm not exited about. I will if I have to but I don't feel I should need to. It seems odd that you can't monitor A/F ratio with the pc. On the fuel injected v-8s that I build I can monitor it on my pc. But I need to, when its on my dyno the O2 senors that I tune the engine with stays with the engine in app. With some apps such as a twin turbo setup with a duel fuel system this is very important. Primary fuel system consits of 91 octane pump gas and runs all the time and under boost conditions we introduce 116 octane fuel, blending the two. Record hp on my dyno todate with a twin turbo 431 ci small block chevy is 2138 hp with 1881 ftlbs/tq with a very flat curve. None of this has anything to do with what I'm dealing with now, just saying that I've played with acouple engines. I guess I will do some more playing around and let you guys know what I come up with. Thanks for all your input it is greatly appreciated!
 
As it applies to the Super tuner and a stock HD bike, the reason you can't just view or change the A/F map and expect the exhaust value to follow suit is because the bike uses a narrow band O2 for ECM feedback. Narrow band sensors only understand stoichiometric and nothing else. Any A/F ratio outside of 14.2 to 14.7 is just seen as Rich or Lean and does not have a specific value. Now if the bike used wide band o2 sensors, and the ECM firmware was written to understand O2 values from say 10:1 to 15:1 it would be able to smart tune and follow each cell in the A/F ratio table and make corrections on the fly. But once you correct the VE tables in order to sync the desired A/F table to actual exhaust value, you are set. From That point you can just change the A/F table and exhaust will follow what you entered. But change just 1 thing on the bike and your back to the beginning once again. You will have to resync the whole shooting match 1 more time.

Take a look at a standard base HD MAP for a Stage 1 and compare the VE tables front to rear. You will see that the rear cylinder runs richer than the front even though the common A/F map says both cylinder are running at the same mixture.

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But back to your problem. It may mean nothing but way back when in the days of tubular headers on small block engines, it was common to see the headers glow right at the neck where the headers and cylinder meet. But when you increased RPM above glow RPM, the glow did not weaken.

Can't you just "choke" the carb to see if the glow goes away because you forced it real rich ?
 
I thought about the glow of headers on a SB engine aswell, thats why I wondered if this may be normal. Also my dad used to work on alot of irrigation engines when i was a kid and the exhaust manifolds would glow red, but this was after a long period of time running under a heavy load. I think the reason the glow would somewhat weaken is cause when i would accelerate above the 2000-2500 mark if would get a pump shot and then the slide would open thus removeing the lean condition.
Now, I just come back in from the shop to tell you guys, I figured it out. Beyond all my belief and prior testing I found a vacuum leak. I know I know I said it didn't have one, and that I check it and blah blah blah. lol!! Just goes to show you that even an experienced mechanic such as myself can still make mistakes. My dad always said if you never mess anything up, then your not doing anything worth doing. I feel like I know nothing when stuff like this happens, makes me wonder why I keep doing it. I know why CAUSE I LOVE HORSEPOWER!!!!!!!!!!!!!

Hobbit, this engine is actually very streetable and very reliable idles at 900 rpm smoothly and it does run on pump gas and if the boost is turned down from 38 psi to about 6 or 8 it wouldn't need the 116 octane fuel.

Now back to Hoople, does anyone make a better ecm or a more self manageable one for HDs? Sounds like someone needs to maybe I......................????

Thank you fellas I'm glad to know about this forum now and will be back again and again. Some very smart and careing people here.
 
Well guess what guys, its not a vacuum leak. I sprayed brake clean on the intake flanges lastnight while it was running, immediately after doing so the engine sound and rpm changed. (Ah ha, vacuum leak) turns out I was spraying it into the back of the A/C aswell, original problem still exists. Today I took a couple hrs (while I should've been working on customer stuff) pulled the pipes and welded in some bungs, and here is what I found, at an idle it is 14.5 at the rpm I'm haveing problems with it was 15.4 and if I take it up to 3200 it is 14.7. I think this is a natural instinct of this carb. I think this because at 2000-2500 rpms steady speed the slide is not open, therefore the carb is feeding from the idle circuit. If I put a bigger pilot jet in,it will most likely be too fat at idle. :wall
 
Would you know the make and model of the carburetor. I have some tuning manuals on Mikuni if that is what you have.

Did you perform a heater and free air calibration on your wide band set-up before using it?

DavesKystoms said:
at an idle it is 14.5 at the rpm I'm haveing problems with it was 15.4 and if I take it up to 3200 it is 14.7. I think this is a natural instinct of this carb.l
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I don't have a lot of experience with carburetors on bikes but I have never seen numbers that lean on any carburetor-ed cage engine. I think your sitting on the problem because 15.4 is over the top. I just can't see that being a natural instinct of any carburetor.
 
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Found a crack in the carb, staright in towards the intake on the bottom. Anyone ever seen this?

In the throttle bore.
 
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I know this is probably inconvenient, but are you able to post a picture? Was the crack near an "intersection", near a mounting point, hole, cavity or thin area of the casting?
 
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