never ending saga - have more questions
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SuperBike
Joined: Nov 2005
Posts: 1,011
never ending saga - have more questions
whipped things back together today. put the k&N back in while I was at it... used 185/190 with recommended settings by dynojet for needles and mixture screws. runs alright but noticed no coolant leak. Also noticed though that the reserve is EMPTY..... argh. well that was after running it for a lil so... let it cool down then check? or what. Might mean that the reserve is leaking... Also i'm still frikin perplexed with the k&N. it's weak down low and slow throttle response - carb synch off maybe?? up top it pulls and things are much better... um... those are my first observations. So gimme tips on those then I'll probably have more later
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SuperBike
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carbs when i got the bike it had 175f/180r 5th notch for the needles. I bumped it to 180f/185r same notch which was probably rich. Tried switching to 190/195 at 4th notch and it was backfiring like crazy with no airbox. dropped it down to 185/190 at the 4th notch and it's sluggish down low. I have a feeling it's partially carb synch but that the needles might need to be bumped 2 up or I go back to 190/195 and try some of the lower needle settings on that... The erion exhaust poses slight issues because it's a high flow baffle but following the dynojet directions exactly would mean 190/195 because it's 180/185 for high flow exhaust/baffle and then bump up 2 jets for k&N. needle recommendation is 4th notch
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World Champion
Joined: Dec 2004
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From: Fulton, MO
Bah! Don't go by anything DJ recommends. Not saying that they suck (directly anyway) but every bike is different and they might be at a different elevation and did the dyno on a hot day. With that said....
So you just added the K&N then? If it was running rich before and sluggish down low and now you add the filter, that should cure the richness up top, but K&N filters don't flow significantly more at lower air velocities so I'd drop your needle down a bit to lean it out on the bottom end. Check your mixture screws 2 turns out and of course sync the carbs. You should at least check it every time you pull the carbs. It doesn't take that long. Hell, I got mine to where I can hook it up in about 5 minutes.
Oh, and how'd the coolant check work out? Fill the overflow with distilled water if you suspect a leak. Check the rad level with the bike slightly warm. Top off with distilled, NOT potable.
So you just added the K&N then? If it was running rich before and sluggish down low and now you add the filter, that should cure the richness up top, but K&N filters don't flow significantly more at lower air velocities so I'd drop your needle down a bit to lean it out on the bottom end. Check your mixture screws 2 turns out and of course sync the carbs. You should at least check it every time you pull the carbs. It doesn't take that long. Hell, I got mine to where I can hook it up in about 5 minutes.
Oh, and how'd the coolant check work out? Fill the overflow with distilled water if you suspect a leak. Check the rad level with the bike slightly warm. Top off with distilled, NOT potable.
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SuperBike
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working on the coolant.. I'm assuming it was slightly rich before. it popped a lot more on decel. Original setup wasn't bad when I got it but it stumbled low. I'll try dropping the needles some. I really need some mercury gauges though so I can setup mine to synch real well and easily. Do you have something rigged to your front cylinder to keep a hose on it? that'd be great if I could do that. it's a pain to remove that screw then get it back in
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From: Fulton, MO
No. I've got a tee on the rear line and got the removal of the screw down to a science. A little grease on the end of the allen socket does wonders to prevent it from falling off. Just have to make sure the sealing washer stays with it.
Popping on decel, eh? PAIR removed?
Popping on decel, eh? PAIR removed?
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World Champion
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From: Fulton, MO
Yup, that's the vacuum fitting for the rear cylinder that you can install in the front, thus avoiding having to take out the stupid screw every time.
Yeah, try the choke thing. It's hard to tell what "sluggish" is if you're not there to hear and feel what's happening. Usually sluggish is rich. Hesitation and surging indicate lean.
Yeah, try the choke thing. It's hard to tell what "sluggish" is if you're not there to hear and feel what's happening. Usually sluggish is rich. Hesitation and surging indicate lean.
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SuperBike
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welp... I cashed in for my upcoming bday and converted a promise to buy my some new computer speakers for taking the bike to the shop to get fixed... That means find and fix the coolant leak, reflush the system with the new coolant since I added in distilled water, synch carbs, get it running well. They had me drop off the jet kit and I gave them the stock filter too in case they decide to just switch back to that... should have it back next week I hope
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SuperSport
Joined: Nov 2005
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Yeah,
I struggled with this same mod for about 3 weeks. I wrote several posts on it, including a step-by-step for a carb synch and installation of the tube on the front cylinder for easy synch. I happened to have an old SH engine around so I just pulled off the spigot from the old rear cylinder and used it on my current engine, then Tee'd it to the other cylinder. Blocked off the hose with a cap and that's it.
By the way, you dont need mercury gauges, just about 6 feet of 1/4" clear hose, a piece of plywood, and some colored fluid (I like transmission fluid), and you can get reliable results.
I eventually went back to the stock setup, because after exhausting research and endless debate, it appeared that the K&N offered no advantage.
I struggled with this same mod for about 3 weeks. I wrote several posts on it, including a step-by-step for a carb synch and installation of the tube on the front cylinder for easy synch. I happened to have an old SH engine around so I just pulled off the spigot from the old rear cylinder and used it on my current engine, then Tee'd it to the other cylinder. Blocked off the hose with a cap and that's it.
By the way, you dont need mercury gauges, just about 6 feet of 1/4" clear hose, a piece of plywood, and some colored fluid (I like transmission fluid), and you can get reliable results.
I eventually went back to the stock setup, because after exhausting research and endless debate, it appeared that the K&N offered no advantage.
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SuperSport
Joined: Dec 2005
Posts: 963
From: Sunshine Coast, Australia
I am hearing your pain man!!!!!!
I was having problems with my bike as well, and I have been working on bikes for near on 20 years. It was personal pride that made me go on, I knew that I had the knowledge to get it sorted. In the end I gave up trying to test the changes I made on the road, it was just too hard, and it took a long time to make changes and then test the bike again. After an hour in the shed, by the time I got back on the bike and ridden out to the highway, I had forgotten what it was like the last time I rode it. After a month I gave up and put it on the dyno.
The dyno guy gave it back and said it was sweet, but as soon as I got on the highway again I knew it wasn't right. It was surging at constant throttle between 500 & 6000 RPM. Under WOT it was fine. I tried every jetting combo I could think of, changed velocity stacks, varied the air intake to the airbox, removed the fuel tap, removed the fule pump I fitted and went back to gravity feed, everything I could think of. No luck, I was stumped.
I was running an Australian made Unifilter which had a much larger surface area than the K&N. It was dyno tuned for this filter and was running 50 pilots and 205 mains, and was producing good power and torque.
So I started working on something else for a while. Then I remembered I had a K&N filter under the bench. So I cleaned it up and chucked it in, and the problem disappeared!! After another dyno tune I ended up with 175 mains in it, and no more surging. I lost 5HP between 7000 & 8000 RPM, and couple of Ft/lb of torque, but it is much more streetable.
So the conclusion seems to be that the Unifilter was creating turbulence at a certain rev range and effecting the carb slides. Looks like a good race mod, but not for the street. Some work on a flow bench may sort out the combo for street use, but it will cost some dollars.
I was having problems with my bike as well, and I have been working on bikes for near on 20 years. It was personal pride that made me go on, I knew that I had the knowledge to get it sorted. In the end I gave up trying to test the changes I made on the road, it was just too hard, and it took a long time to make changes and then test the bike again. After an hour in the shed, by the time I got back on the bike and ridden out to the highway, I had forgotten what it was like the last time I rode it. After a month I gave up and put it on the dyno.
The dyno guy gave it back and said it was sweet, but as soon as I got on the highway again I knew it wasn't right. It was surging at constant throttle between 500 & 6000 RPM. Under WOT it was fine. I tried every jetting combo I could think of, changed velocity stacks, varied the air intake to the airbox, removed the fuel tap, removed the fule pump I fitted and went back to gravity feed, everything I could think of. No luck, I was stumped.
I was running an Australian made Unifilter which had a much larger surface area than the K&N. It was dyno tuned for this filter and was running 50 pilots and 205 mains, and was producing good power and torque.
So I started working on something else for a while. Then I remembered I had a K&N filter under the bench. So I cleaned it up and chucked it in, and the problem disappeared!! After another dyno tune I ended up with 175 mains in it, and no more surging. I lost 5HP between 7000 & 8000 RPM, and couple of Ft/lb of torque, but it is much more streetable.
So the conclusion seems to be that the Unifilter was creating turbulence at a certain rev range and effecting the carb slides. Looks like a good race mod, but not for the street. Some work on a flow bench may sort out the combo for street use, but it will cost some dollars.
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