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Thread: Check those crank case bolts on those surface drives:

  1. #1
    Member mainer_in_ak's Avatar
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    Default Check those crank case bolts on those surface drives:

    I was pushing 70 salmon, two men, and about 30 gallons of water back to the bridge on the Kenai during dipnetting season. The load had the little motor working hard. The rear crank case bolts became loose. I soon discovered this when my motor wasn't getting gas because the pulse pump operates off crank case pressure. I caught it in time and tightened up the three top crank case bolts. Lost a little bit of oil, and the gasket was damaged. Luckily, there is zero damage to the internals of the motor. I'm going to use locktite on all the bolts when I torque them down. I'm uncertain if gasket-maker will work, but I've no time to wait on a real gasket.

    Reach back there with a wrench, and check those bolts occasionally, most of these small briggs, lct, kohler, and honda motors has a crankcase with bolts:

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    Member mainer_in_ak's Avatar
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    torque specs called for 20 ft lbs in the service manual. I set the torque wrench for 23 ft. lbs of torque.

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    Member sayak's Avatar
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    You may want to tab your bolt heads.

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    Moderator stid2677's Avatar
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    Quote Originally Posted by sayak View Post
    You may want to tab your bolt heads.
    Or drill the heads and use aviation safety wire.
    "I refuse to let the things I can't do stop me from doing the things I can"
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    Member sayak's Avatar
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    Quote Originally Posted by stid2677 View Post
    Or drill the heads and use aviation safety wire.
    That's even gooder.

  6. #6
    Member mainer_in_ak's Avatar
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    crank case pressure back, valves adjusted, time to finish up season three. The great stuff gasket maker seems to be holding up fine. It's got about double the viscosity of normal black rtv. Next season, gonna get the head shaved .030" and hopefully bring that compression ratio from 8.0:1, up to about 9.0:1. The lifters and the camshaft are going to get sent off to delta for a re-grind for more torque. Already have a free-flowing muffler installed.

    Man these motors are easy to work on. almost too easy.

  7. #7
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    When an manufacture designs and build an engine they look at hp and reliability. By changing the design you sacrifice reliability for very little gain in hp and you run it harder because you think you can. I would think long and hard about what you want to do, if you blow the engine how will you get out. Just saying.

  8. #8
    Member mainer_in_ak's Avatar
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    when a manufacturer designs an engine, they do so for a global market. Some countries have petrol that is such low quality, it should be named ditch gas. we don't have ditch gas here, we have good 87 octane. Shaving the head on a motor is a very common practice, the valves can be adjusted accordingly. If I wanted unreliabilty.....I'd be running a ford trition engine (remember your thread?).

    Anyhow, getting the compression up for our high quality 87 octane, aint gonna hurt a thing. I've had my fair share of rebuilding landcruisers with shaved heads, and have also dealt with delta camshaft co. Another concern, is the material that the crank shaft is made of: ductile iron, or forged steel. I have a forged steel crank shaft, you aint hurting this. I have the proper exhaust to handle the flow needed for increased compression.

    concerns of difficult starting doesn't apply for the increased compression. This motor has a compression release that slightly bumps the exaust valve when turning the engine over. HEAT can be a concern though, but there are far too many atv's out there running aircooled engines with compression ratio's around 9.0:1

    I appreciate the concern though, thanks.

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