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Post by regularman on Jun 30, 2013 19:48:14 GMT -6
Hey folks, I look on here every once in a while and appreciate you all. Let me explain my problem. 86 en450. I did a frame off redo of this bike and put some different pipes on it and I did not replace the stock air box but made some adapters so the pod type filters would fit the air box. The bike would run good up to about 4.5k and then it started kind of getting lean and weak and stuttering. I went up on the mains and it would still run good at 4.5k get weak from there until 8.5K and then it was all power(more than ever). Riding with friends though I would fall behind and then have to gear down and rocket back up to the pack. I cut about 2 rounds off the springs for the slides and now the thing is great all the way up to 7k and that makes it great for the road but from 7 on up its weak and lean even where it had full power before. Do you folks think I should cut some more off of the springs? I am not understanding why cutting the springs made me lose my power at the top end. Thanks  |
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Post by Blaine on Jun 30, 2013 21:38:44 GMT -6
Hey folks, I look on here every once in a while and appreciate you all. Let me explain my problem. 86 en450. I did a frame off redo of this bike and put some different pipes on it and I did not replace the stock air box but made some adapters so the pod type filters would fit the air box. The bike would run good up to about 4.5k and then it started kind of getting lean and weak and stuttering. I went up on the mains and it would still run good at 4.5k get weak from there until 8.5K and then it was all power(more than ever). Riding with friends though I would fall behind and then have to gear down and rocket back up to the pack. I cut about 2 rounds off the springs for the slides and now the thing is great all the way up to 7k and that makes it great for the road but from 7 on up its weak and lean even where it had full power before. Do you folks think I should cut some more off of the springs? I am not understanding why cutting the springs made me lose my power at the top end. Thanks It sounds like you are still a little lean on the top end.You may need to shim your needles up a little more (higher is richer) or go up a little on the main jet.Don't forget your needles control throttle from 1/4 to 3/4 & M.J. 3/4 to full throttle.  |
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Post by regularman on Jul 1, 2013 10:51:59 GMT -6
Well the thing is that I had good top end power until I cut the springs off. Wide open and wound up it was perfect. I weaken the springs to help the mid range and I am dead up top. I got a bigger set of mains and I may try those.
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Post by carpaltunnel on Jul 4, 2013 10:47:25 GMT -6
I'm going to try and shim my needles but I wonder is there a specific shim that works best? Or method of adapting something to be a shim? My needs don't have different settings to adjust itself so I need to actually add a piece under the head of the needle. If that doesn't solve my mid-range throttle then I'll cut the spring and see what that does.
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Post by Blaine on Jul 4, 2013 17:37:13 GMT -6
I'm going to try and shim my needles but I wonder is there a specific shim that works best? Or method of adapting something to be a shim? My needs don't have different settings to adjust itself so I need to actually add a piece under the head of the needle. If that doesn't solve my mid-range throttle then I'll cut the spring and see what that does. 3mm fat washers. |
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Post by carpaltunnel on Jul 5, 2013 12:03:43 GMT -6
Okay I installed two shims in each carburetor and she sounds a LOT better. I haven't gotten her out on the road yet as weather seems to be getting worse for the day. She still still hesitates when throttle is punched, though. If I ramp up at a slower pace she'll be fine, but if I jerk the throttle she revs, hesitates and then "catches" and really roars. What's the cause of that?
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Post by Blaine on Jul 5, 2013 14:20:04 GMT -6
Okay I installed two shims in each carburetor and she sounds a LOT better. I haven't gotten her out on the road yet as weather seems to be getting worse for the day. She still still hesitates when throttle is punched, though. If I ramp up at a slower pace she'll be fine, but if I jerk the throttle she revs, hesitates and then "catches" and really roars. What's the cause of that? If you haven't got it out on the road yet may just not be fully warmed up yet.Hard to tell until you get a road test done. |
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Post by regularman on Jul 6, 2013 13:28:31 GMT -6
OK, I tried going to bigger mains and it made the situation worse. It started to make the mid throttle worse and no top end power at all. I wonder if I had too big a main jet and should go back to the original once the bike cools off.
I am thinking this is what might be it. I took some coils off the springs which I never did before and so maybe the needle was never fully opening before. That might explain why I had poor midrange but good a full open. Since the needle was not full up, too rich of a main might have been just right because I wasn't getting all from the needle. Now that the spring is changed and the needle is going full up, the too rich main is causing poor performance at full throttle. I have shims under the needle as well that I might not need(or need as much).
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Post by regularman on Jul 6, 2013 17:34:18 GMT -6
OK, back to original main jets and no shims under the needle. It runs great until the last 3/4 throttle then it bogs. I have another set of original springs. I just can't get what is going on at top end. The weakened sping helps the mid range and don't even need shims but it kills the top end power. Original mains 126 went to 130 then up to 144 and its still the same loss of top end power with the cut off springs.
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Post by Blaine on Jul 6, 2013 19:19:51 GMT -6
OK, back to original main jets and no shims under the needle. It runs great until the last 3/4 throttle then it bogs. I have another set of original springs. I just can't get what is going on at top end. The weakened sping helps the mid range and don't even need shims but it kills the top end power. Original mains 126 went to 130 then up to 144 and its still the same loss of top end power with the cut off springs. Are you getting full air flow. |
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Post by eaglerider on Jul 6, 2013 20:55:12 GMT -6
OK....here goes......I don't remember....did u ever do a good valve adjustment??? Others have had about the same top-end problem, then finally, adjusted their valves good, and the bike came alive. May not be ur situation, but I had to ask.
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Post by regularman on Jul 7, 2013 8:07:46 GMT -6
I am pretty sure its not the valves eagle rider. I know what its like when valves don't shut all the way. I gauge mine on the wide side and I don't care if I can hear a click at idle. If you can here them then you are not going to burn a valve and it might give some forgiveness in an over rev. Besides that, I have full on high end power with the original springs back in the slides. I need to learn more about the interaction of the last part of the needle that is used along with the main in that last 3/4. I got the pods adapted to the original air box. I got to figure this all out and then I will post pictures. The kick in the bottom is that I have worked on carbs a lot. I got special screwdrivers and jet drills, gauges, etc and have fixed a lot of them. I worked on carbs to make extra money and only gave it up when the wife got fed up with people showing up and reving hardlys and stuff in the evening wanting me to fix. This just goes to show that no one is ever an expert on anything. I could actually go back to the stock filters without much ado but I would have to buy them because the others were in such bad shape.
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Post by eaglerider on Jul 7, 2013 12:06:42 GMT -6
There is a very good write-up on tuning these CV carbs on our parent website, in the left hand sidebar.
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Post by regularman on Jul 28, 2013 20:02:05 GMT -6
Just a follow up. I been riding the bike as is and it is still weak to little power at the very top. One side effect today that I noticed. I filled the tank full and went for a decent ride with some stop and goes and some interstate riding and some curvy mountain roads. I went 77 miles and was shocked when I filled the tank again and it only took 1.3 gallons. With the other setup it would have taken near 2 gallons. Bike has more low end power than it ever had since new and since 1986 I never got over 50mpg with that bike no matter how I road it. Picks right up to pull hills now in 6th gear and near 60mpg. I can give up it not being able to run 100 and only about 85 for that kind of extended range. I want to take it on a long interstate ride now and see what my mpg is. It used to always be around 40mpg and I would hit reserve at 100 miles or so.
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Post by Jet⚡Black on Jul 29, 2013 15:22:45 GMT -6
Mid range problems are usually due to the lack of back pressure there is a typical way to solve that, add some restriction on the pipe, this can mean different mufflers or slapping a large nut and bolt in the end, or the not so typical, float height first you wanna make sure it is set where it is supposed to be if it wasn't set it and see what mid looks like, if float heights were what they should be, increasing the float height 1 to 1.5mm over stock knocks the mid range nonsense out.
It's my opinion that you've been chasing around a float height issue, one thing hasn't solved it so you jump to something else making the first a little better and making something else worse in the end. When this happens you back up and look to see what else it could be, otherwise you're gonna keep chasing the issue around until you find it, at that point one would hope things are not so far out of whack that they can do their job properly. Check your float height and float jet's and seals. Nothing so far has made them worse, the spring mod is fine and so is the shimming etc. but yeah see what's up with the floats, they are causing you a lean condition from mid to top end, the needle height will expose more gas out of the bowl, but if the fuel level in the bowls are wrong from the floats the condition won't clear no matter what you do.
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Post by regularman on Jul 29, 2013 18:08:02 GMT -6
You might be right about the float levels. I have not messed with them much and I could probably use a couple of new needles for the floats and check that. Its just running so well right now that I don't want to mess with it any more for now and just ride it. 200 miles yesterday and it was a blast. I am 3 miles from the blue ridge parkway and the monsoons seem to be over and the BRP is calling my name. My set up is a little different than most with a couple stock electraglide slipons on it and the sound is just right to me so I don't want to baffle it any more. I think I will wait until this winter and work with it again. Thanks for the help everybody. My bike.  |
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