Pete in PA Posted February 7, 2005 Share Posted February 7, 2005 I got to test drive today. Did a little experiment. during my valve check I drilled my carb. slide vac. hole from 7/64ths to 1/8th in. I know doesn't sound like much. 1/64ths bigger. What a difference! more power, instant throttle response, bike hauls ASS! The only problem is I ran a 1/2 tank of gas empty, then refueled and reset the trip meter. Now I don't know how much MPG I've lost. I can now smell it's a little rich when I stop though. Haven't priced new slides yet, but if it's too much, I think I can JB weld the hole closed and re-drill it smaller. This is like putting in a jet kit for no $$$ If you are a tinkerer and work on your bike. If MPG means nothing to you, go for it. My current setup is slides drilled to 1/8th in. pilot screws 3 turns out. stock exaust, air filter, and everything else. Just checked Ron Ayers, $73 for each slide. :shock: That's $292 for all 4. I hope my MPG isn't too bad or that I CAN close the hole and drill it smaller. Going to be awhile before I can run this tank dry and figure MPG. Quote Link to comment Share on other sites More sharing options...
JB4XX Posted February 7, 2005 Share Posted February 7, 2005 My carbed bike seems to be running like shit lately. I pull back the throttle like going to pass a car and it hesitates before launching. I also feel some surging while 6th gear cruising around 4-5k on the revs. I havent had the carbs synced, dont know if that could be thr problem or not. It is jetted, with a factory jet kit. Pete in PA, sorry to hijack but it sounds like you know your carb stuff. :cool: Quote Link to comment Share on other sites More sharing options...
Pete in PA Posted February 7, 2005 Author Share Posted February 7, 2005 My carbed bike seems to be running like shit lately. I pull back the throttle like going to pass a car and it hesitates before launching. I also feel some surging while 6th gear cruising around 4-5k on the revs. I havent had the carbs synced, dont know if that could be thr problem or not. It is jetted, with a factory jet kit. Pete in PA, sorry to hijack but it sounds like you know your carb stuff. :cool: Thanks for the vote of confidence. Your symptoms are of lean running. both low and midrange. Just putting in a jet kit doesn't make it right, each setting has to be right for your bike and its setup. There are 5 positions for the needle, usually 2 main jets with the kit depending on if you have a high flow exaust or not. It takes some playing to get it right. Is your idle smooth? If it is without hunting up and down the carb sync is good. Quote Link to comment Share on other sites More sharing options...
JB4XX Posted February 7, 2005 Share Posted February 7, 2005 Idle is pretty smooth, hangs right arond 1-1,100. Lean condition eh? Time to run some cleaner through them before I start messing with the needles and such. Quote Link to comment Share on other sites More sharing options...
Northman Posted February 7, 2005 Share Posted February 7, 2005 Time to run some cleaner through them before I start messing with the needles and such. Definitely, especially this time of year, when bike use is low to say the least. Run some SeaFoam through a tank or two, and see how the bike reacts before tearing the carbs apart. Pete, you didn't happen to take any pics during the process, did you? Quote Link to comment Share on other sites More sharing options...
Pete in PA Posted February 7, 2005 Author Share Posted February 7, 2005 Nope sorry no pics. Was just checking the weather thinking about riding to work but at 10 tonight it'll be 35. Might get an electric vest with my tax refund. I REALLY want to get more miles on this setup and see what my MPG is. I like getting 40 MPG. Quote Link to comment Share on other sites More sharing options...
porterb123 Posted February 7, 2005 Share Posted February 7, 2005 For the carbed guys...go to factory pros web site and download their tuning guide for CV type carbs. It gives very good details as to how each circuit of the carb works and how to tune. An easy way to diagnose rich or lean condition while riding is to get the bike up to the problem spot say 5000 rpms and then give the bike some choke...if it gets worse, you are too rich..if it gets better, your are too lean. I was a perfectionist with tuning carbs on my 1100F and spent alot of time with an A/F meter reading plugs and tuning. Good luck Porter Quote Link to comment Share on other sites More sharing options...
cbrxxquad Posted February 7, 2005 Share Posted February 7, 2005 i have done the drill thing and pluged the hole with solder and redrilled Quote Link to comment Share on other sites More sharing options...
Pete in PA Posted February 8, 2005 Author Share Posted February 8, 2005 Well I rode to work yesterday, got 37 MPG. Not too bad considering I rode hard on Sunday for the first part of the tank. I'll leave it the way it is for now and enjoy the new power. For Trurotor2: How did you solder the hole closed? the slides are made of some kind of polycarbonate. :???: Quote Link to comment Share on other sites More sharing options...
cbrxxquad Posted February 8, 2005 Share Posted February 8, 2005 sorry ,i missed which hole you were talking about in the post, was thinking you were describing the transfer to the cv diafram. went back and read better, i was actually refering to holley carbs butterflys we drill for larg cams with low vac to get the idle up and still draw fuel thru the transfer. when we change engines with the carb will plug the hole with solder,,,,, also will pull the plugs in the meter block and drill the idle circuit and then plug the hole back with lead pounded in to seal. none of which will work in plastic not sure if i have anything that will work in mind for that piece "nevermind" :oops: :oops: Quote Link to comment Share on other sites More sharing options...
sk6f3 Posted February 10, 2005 Share Posted February 10, 2005 Why does this work? I am at 7/64 currently. Quote Link to comment Share on other sites More sharing options...
Pete in PA Posted February 10, 2005 Author Share Posted February 10, 2005 Why does this work? I am at 7/64 currently. It works by allowing the vacuum from the engine to pull the slide open faster when you open the throttle. The reverse is also true, when you shut the throttle the slide will close faster. What you get is faster throttle response. Those of you who have done a carb sync and ran the engine without the air box can watch this. As soon as you give it throttle the slides start jumping up and down at each intake stroke. I don't think I'll try any bigger. There has to be a point where the hole is too big and no vacuum will be generated. Once Spring gets here I want to ride it more (of course) to get more of an average MPG. BTW... I got turned on to this mod with my XR650. This is the "standard" mod to get better throttle response from it. Quote Link to comment Share on other sites More sharing options...
JB4XX Posted February 15, 2005 Share Posted February 15, 2005 Time to run some cleaner through them before I start messing with the needles and such. Definitely, especially this time of year, when bike use is low to say the least. Run some SeaFoam through a tank or two, and see how the bike reacts before tearing the carbs apart. Pete, you didn't happen to take any pics during the process, did you? Seafoam smells like shit but did the trick! Ran a couple tanks full with Seafoam in it and the XX is like a cruise missle again! I have been all in the throttle and my fuel mileage went up from where it was too. I was filling up at 150 or so miles, last night it was 180 and thats with extended 85-105 cruisin :oops: :roll: I would reccommend Seafoam! Quote Link to comment Share on other sites More sharing options...
Pete in PA Posted February 15, 2005 Author Share Posted February 15, 2005 I love the stuff also! Wish I new about it earlier, it's been out since 1942. I've got 6 bottles waiting on the shelves for ANY of my engines to act up. Quote Link to comment Share on other sites More sharing options...
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