D&D fatcat.... back to subject....

 

Even with the baffle's in, I still had the popping. Between gears, letting off, sometimes starting. There seems to be a good idle and power, but I'm not sure what it's supposed to feel like since I never rode anything like it. Sometimes hard to start. I'll put the baffles backin but I know it will not get rid of the sound. I've heard other pipes like these and they sound great. The idle mixture screw has been adjusted prior to my ownership. The plug was gone. I turned it out to 2.5 turns for now, I am gonna order the next two sizes up for jets. I will also take off the top and inspect the needle. I did this type of upgrade on my yamaha with great success. A whole lot more power and response. I get decent response with the set-up on my hd, but maybe this upgrade will help. My yami is a twin carb too, so this should be a lot easier to tune.

 

popping will happen in a properly tuned bike with a carb. My D&D pops when I cut the throttle from high rpm. I can tune it out with richening up the idle mix, but, all this does is cause the bike to idle and be too rich. You can turn the idle adjustor out to about 3.5 turns. The idle adjustor is really supposed to set to have the idle running the smoothest. Most all guys that tune a carb flat out tune it too rich. They put a 48 low in there and while their bike runs a but cooler and does not pop on decell as much, they still have the low end way too rich. You want the bike to be tuned to be running between 13-14:1 AFR across the board, if it is tuned correctly and you still get pop, it is either the nature of the beast, or, an exhaust leak. On your evo, a very common setup is a 45 or 46 low, 175 main, and the NOKK or 88 sporty needle mentioned above. Some guys like to use the stock needle and raise it with 2 #4 washers. The idle adjustor is usually about 2.5 to 3 turns out. all these things change though if the intake seals are leaking or the exhaust is. Be sure when you reinstall the carb, run some dielectric grease or dawn around the inside of the o ring that holds the carb to the manifold. This helps to install the carb and get a better seal. Oh, if you can, let me know what needle you have and maybe post a shot of your plugs too.

 

Will do, rounder. Thanks for the advice. With the number that's on these jets, should I leave them alone and do the needle and af mixture? I am gonna check for intake and exhaust leaks after the carb is back together.

 

Yeah maybe...I did not know they actually made a 176 main Jet. Sure it's not a 175? The bike should be good with the low jet being 46 the main jet could possibly go to 180 with you having a cam change. Really the needle needs to be identified and whether or not you have a dynojet kit, yost powertube, or other aftermarket needle and emulsion tube. If your running a stock emulsion tube and needle, you should get a 180, 185, main jets and a NOKK needle. While getting jets and needle, I would also get new gaskets for the manifold to heads and for the carb to manifold anyways. They could still be the original ones and with your bikes age, probably a good idea to just buy new ones and replace them anyways. Also best to get the tool for the manifold bolts too.

 

No pics of plugs just yet. but they were white. Seemed like a lean condtion. I pulled the needle. there are two washers at the top and the number is N86E. jet is definately a 176, maybe 178, but looks more like a 6. I'll leave the slow alone since idle was cool. I'll order up some 180 and 185's today. Should I shim the needle some more?

 

IMHO, dont shim the needle buy the NOKK I listed earlier. Here are my thoughts on shimming the needle: the top of the needle rest perfectly in the slide, the plastic piece the spring goes around rests perfectly along the bottom of the slide...now shim the needle and the plastic piece hovers over the bottom of the slide...see where I'm going here... the spring is then installed and compressed with the cover, with the plastic piece not resting flat the spring bottom can move when the slide is open or closed. COmpress the spring it preferrs to compress into a bend as opposed to straight. this can cause the spring to not react the same way every time...so the slide can start hunting altering the afr while riding. Also compressing the spring more when installed with a shimmed needle actually preloads the spring more and like your shocks this causes the spring to react slower(require more vacuum to move) than it should. So with the spring preloaded more in there it is harder for the vacuum to raise the slide than if the spring were resting correctly. Next thing you need to know is if the vacuum hole for the slide has been drilled... this is a bad move for low to mid rpm running, it also causes hunting and can be a direct cause for pipes popping on decel. Look at the vacuum hole and you should be able to tell if it has been drilled... if so I recommend getting an unmolested slide. The slides are about 40 bucks, but , the bike will pop less and run better especially in cold weather. Oh, hunting is when the slide is moving up and down continuously when the throttle is in one position....giving you more gas less gas..etc... as it will do this when you let off the throttle, it causes popping on decel and between gear changes. The NOKK should not need to be shimmed.

One thing, I cannot tell you how to exactly tune your bike, I can however say that intake leaks exhaust leaks, and a drilled out vacuum hole on the slide can all cause excessive popping out the exhaust. On your spark plugs, you need to look at the base ring of the threads and if there is a layer of black carbon around it(why I wanted a picture of the plug), your not lean, your rich. The ring should be dark but not have carbon build up. If your ring is really light then you may be lean...in your opinion the bike runs good and strong, it just pops on decel...maybe the tune is ok and it could be that you need to get a new slide or look into an exhaust leak to minimize the popping. Maybe you just needed to turn the idle mix screw out a bit more than what it was...I still think the NOKK needle will make the bike run better and maybe it does need a larger main jet, I don't know 100%. Just gotta experiment...and one thing for sure, if the carb is off the bike, I would buy all new seals for the intake to be sure they are not leaking as well. These are the things I would do, and I would not tune the bike to eliminate popping, I would tune it to start well and run strong.

 

Alright. I put in a bigger jet(185) and left the needle alone. Put it all back together and went for a ride. I still had popping. Not anywhere near as loud when I would pull the choke out. So when I got back home, I left the bike at idle and sprayed around the front jug at the intake manifold. The bike stummbled and whe nI would spray enough it would stall. Sounds like this whole problem is the gaskets. Im gonna order new ones and hopefully have this noise fixed. Anyhthing else come to mind that I might need to check when I take off the manifold?

 

check your plugs and compare them to the pictures here
http://www.dansmc.com/Spark_Plugs/Sp...s_catalog.html

 

Just be sure to line the manifold face up parallel with the face of the opening where the breather bolts go into the heads. Then tighten down. H-D sells a tool for the manifold bolts, your gonna want that tool! They sell a manifold alignment tool as well, however an angle finder will work just as good. Whatever you do, do not snug the manifolds to the gasket then align them, it will leak. Get the bolts in, align the manifold then snug it down, check alignment(loosen and adjust if it is off) and tighten. Also, bear in mind, that once the leak is fixed, you will need to retune the bike again, as it will run more rich... IMHO, put the baffles back in, you'll never get the bike to run good without the baffles and are just costing tons of torque and HP in the 2000-3500 rpm range. While your at dealer, buy the NOKK needle, it's only like 8 bucks for the new needle. Not to mention you'll probably really enjoy the way the bike responds with the new needle. I remember a couple years ago when I switched from a shimmed needle to the sporty one...big difference for me. with your baffles in place and no leaks, you will more than likely end up with a 45-46 low speed, 175 main(or your 176), and NOKK needle as the perfect setup. The idle mix screw will be from 2-3 turns out. If you keep your needle you have now and leave it shimmed, the 180 or 185 would probably be best for the main jet. 45 or 46 low.