102 psi of compression

Discussion in 'Engine' started by BlasterPlumb, Sep 8, 2019.

  1. BlasterPlumb

    BlasterPlumb Member

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    Hi everyone , I just picked up a 99 blaster. It was running rough, also heard a knocking sound which seemed to be coming from the top end . Cleaned the carb, made some tweaks , and got it running a little better. Drove it hard for 3 days. It was a little sluggish on the bottom end (don’t think it’s jetted properly for the mods it has) , but was much better on the top end , but still not 100% hitting powerband as it should. On the last ride I ended up having to limp it out in 1st gear, would stall right away trying to give it any more gas. I did a compression test, and came back with just over 100psi. I used a good quality oem gauge with the Schraeder style fitting. What should the compression be in these? Also I realized one of the exhaust studs is snapped , which could be accounting for some of the ticking also. Thanks for any help anyone.
     
  2. Awk08

    Awk08 Administrator Staff Member Technician

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    List mods and current jetting
    check reeds
    check flywheel woodruff key is in place
    check plug boot and connection to wire .... unscrew boot, cut 1/2" off wire, re-screw boot on or replace boot with NGK from auto store
    the exhaust leak is also an air leak as the cylinder scavenges exhaust gases from the pipe
    airleak = fry
    remove TORS, DIY in electrical section
     
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  3. BlasterPlumb

    BlasterPlumb Member

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    Ok thanks for the info I am going to be digging into it shortly and will update. For mods it has a fmf fatty and powercore 2 silencer, I believe force reeds, no airbox lid, oil injection removed. As for the jetting I have no clue what it has for a main , how can you tell are they stamped?
     
  4. Larry's Shee

    Larry's Shee Active Member

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    There's a tiny number on side or end of jet
     
  5. BlasterPlumb

    BlasterPlumb Member

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    I haven’t had a chance to pull the carb yet to check jet size, I will be this evening. But I was able to do a leakdown test yesterday. I found a very bad air leak between the carb boot and reed valve. I put some rtv on it and put it back together. Will be retesting this evening.Also it looks like someone tried to port the reed valve at one point I will post pics. Are these reeds still ok you guys think? Thanks so much for the advice I will update more this evening
     
  6. BlasterPlumb

    BlasterPlumb Member

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  7. BlasterPlumb

    BlasterPlumb Member

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    The current jet is a 230, also the piston looks like it is the one from a Vito’s 240cc kit, so it may be a 240 I’ve yet to come across another piston with that same design
     
  8. BlasterPlumb

    BlasterPlumb Member

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    **UPDATE** after putting rtv black on the carb boot, it fired right up today and seems to be running awesome. I have a little gas coming out of the carb overflow which I believe is just that the float height is off. Can anyone recommend a good aftermarket carb Incase the float itself is no good, I would rather put a decent aftermarket on with easy jet changing for different climates. Also I noticed in the rear axle that there is some up and down play, seems to me that the bearings are shot, Can anyone confirm? I will post a video. And again thanks so much for the help and advice
     
  9. Awk08

    Awk08 Administrator Staff Member Technician

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    STOP !!!! That's going to fry with a 230 main !!!!
    270 thru 310 mains for FMF, lid off, mixed fuel
    start large and plug chop down to required main jet.....
    https://www.blasterforum.com/threads/how-to-plug-chop.53237/

    make sure the oil injection port is blocked off on the carb
     
  10. BlasterPlumb

    BlasterPlumb Member

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    Ok I am putting together an order right now I will try finding them. It also has a hiflofiltro air filter if it makes a difference.
     
  11. BlasterPlumb

    BlasterPlumb Member

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    Yes the oil injection port is plugged, and he put the Vito cog eliminator on as well. I do have a hose coming out if the crankcase though which I haven’t looked into yet I will post a pic. Also do you recommend anywhere to buy the jets , preferably as a kit?
     
  12. BlasterPlumb

    BlasterPlumb Member

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  13. BlasterPlumb

    BlasterPlumb Member

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    Awk thanks for all the help man I just noticed your an electrician, I am a plumber , never got so much help from a sparky in my life respect
     
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  14. BlasterPlumb

    BlasterPlumb Member

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    Im going to run it up under the hood and maybe even put a little filter on to be safe
     
  15. BlasterPlumb

    BlasterPlumb Member

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    I found some on Denniskirk, I’m going to get 250-320 so I have an array of them, all for about $25 shipped . If anyone needs jets they seem the cheapest out there
     
  16. Awk08

    Awk08 Administrator Staff Member Technician

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    All your last posts are good to go, except the filter on that crankcase vent, it'll be fine just hanging up under the hood open to free air
    thumb.jpg
     
  17. BlasterPlumb

    BlasterPlumb Member

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    Awesome, I’m stoked that I got this one pretty much figured out now. I just picked up an 06 blaster, bone stock. Starts right up , runs good but in the top end it is hesitating a bit. Hopefully it’s just a carb issue, but will start with doing a leak down test. For $500 I think I stole the thing, its in great shape. Will update within the next few days, and once again thanks for all the help and support this forum is great.
     
  18. BlasterPlumb

    BlasterPlumb Member

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    I can’t believe it, I just found the same air leak on this new 06 I picked up . Right on the carb boot again, is this a common leaking point?
     
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  19. lucknuts

    lucknuts Member

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  20. BlasterPlumb

    BlasterPlumb Member

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    What do you guys recommend for crankcase oil and capacity?
     

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