El Gringo Posted January 25, 2018 Author Posted January 25, 2018 20 minutes ago, Tombola said: Have you got another set of carbs you can try without the turbo? Yep, i could pull the carbs off my bandit 4 to try, and i may well do at some point, however i'm not sure how well they would work, the GK76a carbs are slightly more down draught and have the float bowls at an angle where as the Bandit carbs are pretty much flat but we can always give it a go 2 Quote
370steve Posted January 25, 2018 Posted January 25, 2018 1 hour ago, El Gringo said: the GK76a carbs are slightly more down draught and have the float bowls at an angle where as the Bandit carbs are pretty much flat but we can always give it a go just like riding down hill with normal carbs!!! dont stop working then do they? 1 Quote
El Gringo Posted January 25, 2018 Author Posted January 25, 2018 47 minutes ago, 370steve said: just like riding down hill with normal carbs!!! dont stop working then do they? Haha, that's very true Steve! In other news i may have found a suitable test spot - here's hoping for a bit of dry on Saturday 2 Quote
Tombola Posted January 26, 2018 Posted January 26, 2018 That’s what I’d do, see if the bike runs right with another set of carbs. Am I right in thinking you have always been having a mare with them ie float heights etc??? Quote
El Gringo Posted January 26, 2018 Author Posted January 26, 2018 2 hours ago, Tombola said: That’s what I’d do, see if the bike runs right with another set of carbs. Am I right in thinking you have always been having a mare with them ie float heights etc??? Not quite, that actually turned out to be the ignition pick up being knackered, but at the time i thought it was something in the carbs As it turned out once i'd changed the pickup it ran perfectly, in neutral anyway, and the floats and settings were good even with pressurised fuel input Quote
El Gringo Posted February 11, 2018 Author Posted February 11, 2018 18 hours ago, Tombola said: You got this running yet?? Not yet chap, been away for a couple of weeks and the weather has been less than helpful Just waiting for a reasonable day for a sneaky road test 1 Quote
El Gringo Posted February 26, 2018 Author Posted February 26, 2018 20 hours ago, Madb said: are we there yet? tap,tap,tap Haha, not quite. It's currently sat under a sheet in the naughty corner. I've actually made a start on refreshing mt 1216 to keep me amused. Just waiting for a better days weather still to give the turbo a run - we've got snow coming in later! I have however spoken to Mr FBM and he gave me some pointers, next things to try is a higher base fuel pressure, then with the bigger holes drilled as they are now and then with them blocked off (as Dave suggested) One way or another we'll get there, it's just going to take a bit of time 4 Quote
Madb Posted March 23, 2018 Posted March 23, 2018 Knock knock, hows it going, @El Gringo? any progress? 1 Quote
El Gringo Posted March 24, 2018 Author Posted March 24, 2018 12 hours ago, Madb said: Knock knock, hows it going, @El Gringo? any progress? Ahhhhhh, errmmmmmm, ya see, ummmmmmmm, the dog ate my home work........... I really do need to get on with it, i might change the front tyre this afternoon to make it a bit more road test friendly (it's got an ancient slick on it at present) 1 Quote
Madb Posted March 24, 2018 Posted March 24, 2018 Bloody Big dog, then! detention after skool hours, sir and write 100 times "I will finish my bike this year" in Latin of coarse!. 1 Quote
El Gringo Posted April 15, 2018 Author Posted April 15, 2018 YeGads! An Update! It still doesn't work. The sun finally stayed out long enough for a sneaky run up the village Several things occured It takes off like a scaled cat and lifts the front in first which surprised me It still gets to mid throttle and goes flat, same as on the dyno I think i got my picture taken by an angry local - i await the pitchforks and burning torches I also now better understand the addiction to the noise - it really is awesome when it starts spooling. Next steps? I have no idea, i tried upping the fuel pressure but it didn't appear to make any difference 2 Quote
Paulm Posted April 16, 2018 Posted April 16, 2018 You can put a little reservoir on the drain,but do you have a restriction in the oil feed to the turbo? There may be too much oil going into the turbo.Mine has a 1mm carb jet screwed into the banjo bolt for the oil feed pipe to the turbo. Quote
Gixer1460 Posted April 16, 2018 Posted April 16, 2018 3 hours ago, Paulm said: You can put a little reservoir on the drain,but do you have a restriction in the oil feed to the turbo? There may be too much oil going into the turbo.Mine has a 1mm carb jet screwed into the banjo bolt for the oil feed pipe to the turbo. This doesn't seem to be an immediate issue requiring a solution? Quote
El Gringo Posted April 16, 2018 Author Posted April 16, 2018 I've got a 1mm jet in the oil feed. Although that wasn't an issue it does seems to have a lot of oil in the up pipe it appears so maybe a i do need a smaller jet. In other news, i'm wondering if I cut the FPR spring down too far. It took a lot of winding in to get it to register on the gauge - it all seems very inconsistent at the moment. Next course of action, new spring, set the FP with it running accurately. When i did ramp up the FP it seemed to run rougher off the bottom which i'm assuming is it being over rich - i ended up back on stock float heights so perhaps i need to look at lowering them again? Also need to find a new test site...... 1 Quote
bruteforce Posted April 23, 2018 Posted April 23, 2018 Hi El Gringo, Got your PM about the carb setup. Although I've changed to Efi because I got tired of boosted carbs, I'll try to help you. Sorry if I'm asking the obvious, I have no time to read all of the 14 pages. I understand from your message that you have drilled a channel like The Vault has documented for the 41mm GSXR carbs? I never did that on my bike(s). On your bike I'd start off with as standard carbs as they come. Check float heights and that's it to start with. Anyhow, if the engine falls flat on its face right at the point where the turbo starts building boost, then your dynamic boost compensation for the floatbowls is failing. Dynamic boost comp is about the pitot tube(s) that you need to fit into the compressor feed tube that goes to the plenum. If you don't have these fitted, or you haven't got this right, it won't work. When your fuel pressure is too low, it won't fall flat on its face right after boost, but it will gently run out of petrol after a while cuz the floatbowls are running empty. 2 Quote
El Gringo Posted April 26, 2018 Author Posted April 26, 2018 On 23/04/2018 at 9:22 AM, bruteforce said: Hi El Gringo, Got your PM about the carb setup. Although I've changed to Efi because I got tired of boosted carbs, I'll try to help you. Sorry if I'm asking the obvious, I have no time to read all of the 14 pages. I understand from your message that you have drilled a channel like The Vault has documented for the 41mm GSXR carbs? I never did that on my bike(s). On your bike I'd start off with as standard carbs as they come. Check float heights and that's it to start with. Anyhow, if the engine falls flat on its face right at the point where the turbo starts building boost, then your dynamic boost compensation for the floatbowls is failing. Dynamic boost comp is about the pitot tube(s) that you need to fit into the compressor feed tube that goes to the plenum. If you don't have these fitted, or you haven't got this right, it won't work. When your fuel pressure is too low, it won't fall flat on its face right after boost, but it will gently run out of petrol after a while cuz the floatbowls are running empty. Many Thanks Bruteforce. That's awesome. I've got a pitot tube feeding the carb float bowls. I'll try blocking the holes that I drilled and go from there Cheers for your help Quote
Madb Posted April 26, 2018 Posted April 26, 2018 Tap,Tap,Tap.... you there yet? hope it's just them holes ,chap. You defo have been on a journey with this one. most enjoyable from where i'm sitting. You'll get there shortly. 2 Quote
Blubber Posted April 26, 2018 Posted April 26, 2018 3 hours ago, Madb said: Tap,Tap,Tap.... you there yet? hope it's just them holes ,chap. You defo have been on a journey with this one. most enjoyable from where i'm sitting. You'll get there shortly. Yep... we still have a bet running "how much bhp when running" 2 Quote
El Gringo Posted April 29, 2018 Author Posted April 29, 2018 Quick update Haven't tested it yet but it's holding 3psi of fuel pressure when running with no over flowing I've run it with the plenum off and it doesn't appear to be pissing fuel out of any of the air jets etc Pitot is 6mm ID in a 30mm ID up-pipe I've also blocked off the holes i drilled with some aluminium two part epoxy stuff so we'll give it a go and see what happens The slides were lifting when running and revved in neutral which proves nothing i realise Now, just need a bit of good weather to give it another test! 3 Quote
El Gringo Posted May 2, 2018 Author Posted May 2, 2018 Thinking a bit more on the pitot setup, It's 6mm ID in a 30mm id pipe. Consensus/Guide on the interwebs suggests 1/4" of Pitot per 1" of Up pipe. Which broadly works out that i've got just under 1/4" (6mm instead of 6.35mm), if we stick with the theory it should be closer to 7.5mm. Would this being 1.5mm undersize cause that much of an issue? I need to run it up again with the 3psi fuel pressure and the holes blocked off to see what it does. Anyone know the cylinder spacings on the 34mm Tin Tops? I looked at the carbs on my Bandit 4 and it won't work with the clamp/silicone set up i've got at present. Quote
Gixer1460 Posted May 2, 2018 Posted May 2, 2018 If the tin tops are aircooled Suzuki then the spacing should be identical to 36mm CV's and 38's and 40's......... 77 - 93 - 77 - centerline dims. 1 Quote
El Gringo Posted May 2, 2018 Author Posted May 2, 2018 4 hours ago, Gixer1460 said: If the tin tops are aircooled Suzuki then the spacing should be identical to 36mm CV's and 38's and 40's......... 77 - 93 - 77 - centerline dims. Ta! Quote
latheboy Posted May 2, 2018 Posted May 2, 2018 Hi El Gringo, How many pitot pipes do you have? I have 3, 1 for the fuel reg and 1 each for 2 carbies into the overflow Ø46.8mm ID up pipe and the pitots are Ø6.00mm each. If you are getting ALL of your boost references from 1 pitot and spitting them over 3 places you might get problems. I didn't drill my slides when I set mine up, Ø38mm carbs, but I did drill a hole to under the diaphragm .. Ø3.0mm I think... it's been a while. To me It feels like the drilled slides are large part of the problem 2 Quote
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