High Compression Jetting
  • MarisC69
    Posts: 8
    Joined: Tue Apr 24, 2018 11:57 am

    High Compression Jetting

    by MarisC69 » Tue Apr 24, 2018 12:31 pm

    Hi!
    My name is Chris and a have a Crf450r 2006 engine (in a 2012 frame)

    Having some troubles to find the correct jetting. If anyone can give some advice will by great.
    So, my bike parts is the follows

    Fcr 41 (2006)
    Hotrods crank with rod 617
    Cylinder works cylinder (stock 96mm)
    Cp piston 96mm for 13.5 CR
    Stock head ( only some polished )
    Stock gaskets
    Stock cam (2005)
    Stock exhausts valve set (new)
    Steel intake valves with dual springs
    FMF power Bomb header
    Leo vince X3 dual mufflers modified to 45mm each.

    Carb jetting.
    (Im on sea level, 30C, supermoto use)
    Pilot 48
    Needle stock honda at 5th clip
    Main 195
    Screw at 1 3/4
    Pump diagraf -2.5mm
    No Oring mod.
    Leak 50
    Bowl level 9mm

    The bike starts at first kick hot or cold without chock. I dont have backfire (if i lower the ar screw i have a lot of bf) but i have some blogs or pops to middle rpm and sometimes the idle stalling a little.

    Thanx for your help.
  • Leardriver
    Posts: 355
    Joined: Wed May 05, 2010 10:33 am

    Re: High Compression Jetting

    by Leardriver » Wed Apr 25, 2018 3:39 pm

    45 pilot, just like the other CRF's, fuel screw 1 7/8 out, main jet 162.

    Higher compression engines are more efficient, and since an engine is an air pump, it can pull more fuel through any given jet.
  • MarisC69
    Posts: 8
    Joined: Tue Apr 24, 2018 11:57 am

    Re: High Compression Jetting

    by MarisC69 » Thu Apr 26, 2018 7:38 am

    Thnx for the answer. Im gonna try this jetting in few hours and post the results.
  • MarisC69
    Posts: 8
    Joined: Tue Apr 24, 2018 11:57 am

    Re: High Compression Jetting

    by MarisC69 » Thu Apr 26, 2018 9:33 am

    I forgot to say, my bike run a little warm. I check timing, water pump and radiators plus hoses but all is good. And, if i turn the fuel screw lower than 2 turns i have bf. My max rpm is to 1 turn (with hot engine) but i have bf to much and the engine turns to cut down like "no fuel" or "thrash in pilot jet". I have install new oem connection on carb and new gasket on exhaust. No leaks. Double triple check. The carb is very clear inside, jets to. Valves are sets as manual , and no engine strange noises or something.
  • MarisC69
    Posts: 8
    Joined: Tue Apr 24, 2018 11:57 am

    Re: High Compression Jetting

    by MarisC69 » Fri Apr 27, 2018 6:45 am

    Ok, with this jetting.
    Idle stable no heat
    mid not prefect but no heat
    Hi revs - full open throttle, over heating. Cap in radiator is 1.6 bar. Im gonna check the plug maybe i raise the main 5
  • Leardriver
    Posts: 355
    Joined: Wed May 05, 2010 10:33 am

    Re: High Compression Jetting

    by Leardriver » Fri Apr 27, 2018 3:15 pm

    Is it overheating while riding? All 450's overheat idling on the stand.
  • MarisC69
    Posts: 8
    Joined: Tue Apr 24, 2018 11:57 am

    Re: High Compression Jetting

    by MarisC69 » Sat Apr 28, 2018 9:02 am

    Is it overheating while riding? All 450's overheat idling on the stand.

    Yes, while riding. I put a 180 main and the spark plug looking very good plus the overheating in f.o.t. stopped. Maybe i must change the needle 1 clip up. I open the right side of engine ang the water pump cover to ensure for leaks. All good. Maybe the opened boot of 2012 and the twin air filter acts deference from 2006 to the mix. I check the spark plug tonight again. But with 45 pilot and 2 turns, the idle are stable now with no b.f. thnx a lot.
    One more, i have all the stock jetting of 2002-2008 X and R models 250 and 450. If anything gonna help anyone just show my the way
  • MarisC69
    Posts: 8
    Joined: Tue Apr 24, 2018 11:57 am

    Re: High Compression Jetting

    by MarisC69 » Sun May 13, 2018 3:51 am

    Problem solved. Leak from head gasket to cooling system. Deck ok new gasket and all perfect. 160 main 4th clip the needle and 45 pilot.
    New problem. After this i install stage 3 hot cam. Cp is now 13.8. The problem is, when i put out air filter is running good except 1/4 1/2 but when filter is up.. is a very slow bike... I drop the main to 155 with out air filter and gain power. Im gonna raise the pilot to 48 to see the bottom end power (i dont waiting to see a lot of power cause the cam is for mid and high power. Just an easier starts, now needs 2 3 4 kicks). After i see the plug to 1/2 and to WOT to solve it. I post the results after for database.
  • MarisC69
    Posts: 8
    Joined: Tue Apr 24, 2018 11:57 am

    Re: High Compression Jetting

    by MarisC69 » Sun May 27, 2018 8:12 am

    Finally! For the records....

    Pilot 48
    Mixture screw 1 3/4
    Main 150
    Needle clip 5 (from top)

    Running like the hell... starting with first kick and no bogs or back fire
  • Aussiecrf230
    Posts: 1541
    Joined: Fri Jan 06, 2006 11:11 pm

    Re: High Compression Jetting

    by Aussiecrf230 » Mon May 28, 2018 1:27 am

    Thanks for the feedback I am sure it will help others
    Ray
    Australia

    CRF230F 2004
    C30F Power Up needle
    Mains 132
    Idle 45
    2 turns out
    Baffle out, Screens In

    It starts,it runs,it gets to where all CRFs can get to without the valve or valve plate dramas
  • Leardriver
    Posts: 355
    Joined: Wed May 05, 2010 10:33 am

    Re: High Compression Jetting

    by Leardriver » Mon May 28, 2018 5:42 pm

    It is starting first kick because your pilot is too rich. It will run, but a 45 is better.
  • MarisC69
    Posts: 8
    Joined: Tue Apr 24, 2018 11:57 am

    Re: High Compression Jetting

    by MarisC69 » Tue May 29, 2018 4:17 am

    Nop, spark plug is colored as ngk manual. Forgot to say i replace the oem air filter with KN free air filter. If im going to 45, getting hot, dont start if i dont pull the throttle one time, and i have back fire. I test 2 weeks the bike. 48 and 1 2/4 - 3/4 its top. I change the screw to a new one, and nothing.

Who is online

Users browsing this forum: No registered users and 2 guests