building a new bike for my wife, as usual the bike came complete but in pieces!, building a lower cafe custom with an assortment of other year parts. motor - 2008 ex250 with 5000km on the clock frame - 2003 ex250h7 forks - 2003 ex250h lower through triple trees wheels and rotors - 2008 ex250 sub frame - 2008 ex250 rear section of frame shortened and lowered (new design mounting point) handle bars - clip ons - 50 mm with machined adapter collars tank - small after market sportster tank (kicking around shed) headlight - as above seats - 2008 oem set speedo and temp - zxr250c (need to purchase these) oem 2003 wiring loom engine warning lights - after market no fairings (all body work around seats - plate alloy) colour - satin black / glass blasted alloy / gloss black Have spent about a week and a half fitting everything and tonight we fired up the motor to check how well it ran, sweet as!, just have to adjust mixture (worst location I have seen for the mixture screws yet, easier to just rip carbies off, adjust them and re-install. I'll post pictures when it 90% complete.
welded out sub frame and fabricated tank mounts today, looking at building a type of under seat type exhaust.
I thought the ninja 300 looked good, until I sat on the this bike! being a transition between the ex250H7 (zzr250) and the ex250j (Ninja 250R) models, I have labelled it the ..... View attachment 12801 View attachment 12800
The H8 is about 95% complete, road tested today, all good. just to install indicators, battery, bar end mirror sand fabricate the twin mufflers (twin system on right hand side, similar to the two stroke system picture below.
I have done a massive amount of modifications to the H8 since my last post, repositioned every single electrical unit under both seats, machined a complete tunable muffler system, fabricated high flow filters, installed cooling fan on rectifier to monitor temp, installed sealed slimline battery under rear seat. Posting pictures and info now.
electrical system installed under both seats, sealed acid battery under rear, low voltage flasher relay, cooling fan installed on rectifier between seats etc.
Machined mufflers, slip-on units that cover the resonator chamber and the flow cage (factory tuning) baffle material and flow spiral to spark arrester mesh, through the removable tuning plate and the spring retainer ring (tuning plate hole is std flow rate for a starting point with tuning) tuning plate is removed via spring retainer
I got rid of the standard air box and wanted hi-flow filters on the carbies, using stainless steel wire, I bent up spring clip harnesses to hold the fine s/s mesh and filter elements onto the inlet rubbers (s/s mesh is both sides of filter elements ) the carbies require a small amount of flow restriction to get idle settings correct, they wont tune if no restriction to air flow into carby is provided. With the exhaust as it is at the moment and the air flow, the needles require shimming a little, going to install a Factory Pro Jet Kit. Considering what the bike is mainly built for I wont be looking at re-jetting for a while, It only needs to do about 130 km max.
I will get back onto the ZXr250 now this one is done, it's mainly head work that needs doing now, have to work out weather to run the valves I have (not real happy with then) or new valves and a valve seat cut.
The H8 is finished and waiting on registration, I need a carby tech or someone with good skills to add some advise! This is the path the tuning has gone, bike came with #105 mains because of the high flow mufflers (twin system), high flow (mild restriction) filters, I assumed I would need a slightly larger main and maybe needle shims to start with. Each test I run during tuning I took plug readings, temp readings on headers, radiator tanks, crankcase and mufflers (to record and changes tuning is doing. #105 mains / 1 (0.75mm) needle shim / 2.75 turns out (fuel mixture) result ; spluttering at mid rpm #105 mains / 2 shims / 2.75 turns out result : same as above #110 mains / 1 shim / 3 turns out result ; worse ( couldnt get to 70km/ph) #110 mains / no shims / 3 turns out result : as above #100 mains / no shims / 3 turns out result : runs well, pulls ok, splutters at upper mid rpm ran motor to temp, synchronized carbies to 2 degrees variant between exhaust headers, checked float levels - correct (OEM 17mm) couldn't get #98 mains so thought I would try #95 mains. #95 mains / no shims / 3 turns out / result : pulls hard like a cut snake!, revs to 10 - 11k/rpm very quickly, plugs excellent reading, temps on headers (2 degree variant), radiator tanks (6 degree variant), crankcase excellent (2.8 degree variant). From 11k/rpm there is the smallest splutter and will slowly clear itself around 12k/rpm I dont really want to push the motor in this area until I sort out the splutter! To me it is still rich! will lowering fuel bowl level lean out the splutter it has? Or - go a step down in Mains? install Factory Pro needles to lower needle position ($110 for a kit, a lot of money to experiment with such a tiny tuning fault) what do you think my friends!
Hey chuck, Kiffsta is selling an A series motor (more powerful, but that might just be carbs and CDI) for $300, complete and running. I might even have a transport option.
He has a few bikes, including a ZXR C series (I know, I sold it to him, with the shot valves), the A series should be the same, right?
