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Author Topic: 79 yamaha srx 440 timimg  (Read 918 times)

vern

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79 yamaha srx 440 timimg
« on: January 11, 2017, 01:17:11 AM »
looking for some info or help with my srx. When pulling over to start sometimes the recoil rope wants to rip out of your hands like timing is off. I checked timing put in dial indicator in plug hole,turned over until i found tdc and set indicator to 0. Turned counter clockwise acouple of turns and then back and stopped at .052-.055 BTDC and flywheel and stator are lined up. cdi box? Strange thing i did have it running after freshing up motor. Any info or help would be great. Thanks in advance.       
1979 yamaha srx     1975 yamaha gpx 433

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    jschaffer

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    Re: 79 yamaha srx 440 timimg
    « Reply #1 on: January 11, 2017, 03:28:47 AM »
    Did you put a new key on the crankshaft for the flywheel?  That can do it.  They are still available from Yamaha.  An old key can have a slight groove in it, throwing off your timing.
    1975 Yamaha GPX 433G
    1977 Yamaha SRX 440A
    1979 Yamaha SRX 440C

    vern

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    Re: 79 yamaha srx 440 timimg
    « Reply #2 on: January 11, 2017, 09:48:10 AM »
    Idid not use a new key. Going to pull flywheel off this morning and check. The only other thought i had was the crankcase filling up with gas after it sat awhile. But turns over fine was the key off.
    1979 yamaha srx     1975 yamaha gpx 433

    srxpc

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    Re: 79 yamaha srx 440 timimg
    « Reply #3 on: January 11, 2017, 02:46:47 PM »
    Double check your connections from stator to cdi. I changed the stator on my 79 and it would rip the recoil out of my hand also. Check my connection again and found I had two wires reversed.

    vern

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    Re: 79 yamaha srx 440 timimg
    « Reply #4 on: January 11, 2017, 11:45:54 PM »
    Ok i'll double check wires and connections. Did start it this morning and i found pulls over fine at full throttle. I'm thinking now maybe crankcase was loaded with gas?? Runs strong mid-range and up top but seems to be really rich still. going to look at fuel pumps and carbs again. took plugs were black.     
    1979 yamaha srx     1975 yamaha gpx 433

    SRXS

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    Re: 79 yamaha srx 440 timimg
    « Reply #5 on: January 12, 2017, 05:43:19 AM »
    Yes it will do that if the crankcase is full.  You should be fine now except for maybe low speed adjustment.

    vern

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    Re: 79 yamaha srx 440 timimg
    « Reply #6 on: January 15, 2017, 10:23:05 AM »
    Update. I changed cdi and starts alot easier. Of course we lost all our snow so cant take it for a ride. I'm thinking of leaving air box off and getting uni-filters. I'm running the PJ carbs with 35 pilot 310main and 80. Have 2.0 slide. I 'm thinking that would be a close start? Any suggestions?? Thanks     
    1979 yamaha srx     1975 yamaha gpx 433

    y2grey

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    Re: 79 yamaha srx 440 timimg
    « Reply #7 on: January 15, 2017, 11:53:29 PM »
    Removing the air box with PJ carbs = seizure
    06 YAMAHA ATTAK
    04 BMW GS 1150R ADV
    03 YAMAHA RX1
    02 SKI-DOO RENEGADE 800
    01 HARLEY DAVIDSON XL 1200C
    01 YAMAHA XLT-IR 1530
    91 SEA-DOO XP 800
    79 YAMAHA SRX 440
    75 MERCURY 440 S/T
    72 CHAPARRAL FIREBIRD 650 SS
    72 CHAPARRAL THUNDERBIRD 650
    43 WILLYS MB

    jschaffer

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    Re: 79 yamaha srx 440 timimg
    « Reply #8 on: January 16, 2017, 03:32:15 AM »
    x2 on the airbox.  They run better and make more power with the airbox.  Those PJ carbs were made to run with the airbox.
    1975 Yamaha GPX 433G
    1977 Yamaha SRX 440A
    1979 Yamaha SRX 440C

    vern

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    Re: 79 yamaha srx 440 timimg
    « Reply #9 on: January 16, 2017, 10:38:32 AM »
    Ok Air box going back then. Thanks for the advice. Another question i had was the adjustment screw on the bowls,does that adjust  full thottle only? Never had these pj carbs. Thanks again   
    1979 yamaha srx     1975 yamaha gpx 433

    SRXS

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    Re: 79 yamaha srx 440 timimg
    « Reply #10 on: January 16, 2017, 02:07:18 PM »
    Mid range and top end.  It controls the main jet.

    back in the day racing

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    Re: 79 yamaha srx 440 timimg
    « Reply #11 on: January 16, 2017, 04:23:59 PM »
    On my 79 I run stock jetting with air box. Main adjuster screw closed. I am at about 950 ft. Above sea level.
    SRX RACER
    There comes a time when the ice and snow will melt.

    back in the day racing

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    Re: 79 yamaha srx 440 timimg
    « Reply #12 on: January 16, 2017, 04:38:41 PM »
    Trying to up load another chart from service manual but can't.will try later.
    SRX RACER
    There comes a time when the ice and snow will melt.

    back in the day racing

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    Re: 79 yamaha srx 440 timimg
    « Reply #13 on: January 16, 2017, 05:00:56 PM »
    About 1/8 of a turn is equal to one jet size.
    SRX RACER
    There comes a time when the ice and snow will melt.

    vern

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    Re: 79 yamaha srx 440 timimg
    « Reply #14 on: January 16, 2017, 10:20:26 PM »
    Ok thanks for the chart. There is 310 mains in there now. I'll put the 340's back in.  My slides cut out are 2.0  i may change them also. I got 1.0  and 1.5.
       
    1979 yamaha srx     1975 yamaha gpx 433