GC 160 engine problems

Discussion in 'Motorized Bicycle General Discussion' started by Wheelwright Restorations, May 9, 2017.

  1. Wheelwright Restorations

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    Great site. I've been lurking for a while while doing my first build.

    I built a Board Track bike with mostly all Sportsman Flyer components.
    Pat's components are all top shelf and are working great.
    I'm using a GC Honda 160 engine. The fan and shrouding have been remove
    I'm using Amsol 20-50 oil (same as my Harley) I have a 22mm mikuni carb
    The jets are set to run slightly rich. Over heating is not a issue.

    My Problems The exhaust rocker arm cracked creating progressive excessive lash till it finally became to much for it to run. OK cheap easy fix for less than $20. Got it back together running well. While running straight out at about 43 MPH The head of the valve separated from the stem. Looks like a new valve and a piston will fix it $50
    The oil had that slightly silvery look all bearings looked good I suspect rapid cly wall wear.

    I'm wondering if this engine is just not a good choice. I'll have it back up in a week or so but if the valve train fails again I'll change engine type.
    I am considering a GS 190 It basically the same as the 160 larger bore and cast iron sleeve. Same foot print just .300 taller. I think Pat's mounting system should work with the 190
    I would also change the rear sprocket to the next size smaller for lower cruising rpms

    The GS 190 is the same design as the GC 160 so it may have the same valve train issues
    Pat says the 160 is the largest engine he recommends on his bike frames

    I added plates with chain adjusters at the drop outs doubling the thickness
    A plate was added where the rear triangle meets the seat post.

    I think he might be a bit conservative when I look at some of the frames people are mounting the HF 212 on.

    I like the looked of the vertical engine an would like to stay with them but I'm not willing to carry a spare.

    Your thoughts and experiences would be appreciated
    Ray
     
  2. Wheelwright Restorations

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    Photo of the bike I want to get any bugs out before powder coat
     

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  3. Wheelwright Restorations

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    engine from other side The air filler has been change to foam type catch can vented to atmosphere
     

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    #3 Wheelwright Restorations, May 9, 2017
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  4. Wheelwright Restorations

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    Gas tank fabrication
     

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    #4 Wheelwright Restorations, May 9, 2017
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  5. culvercityclassic

    culvercityclassic Well-Known Member

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    We have used that engine in some of our past builds, it’s a great engine but does not do well with hi-rpm runs. We ran it with the jackshaft set-up, and blew the top right off the engine when the con rod let loose...too many RPM's. We switched over to a CVT and limited the rpm's and had no more issues. I would say run it but limit it to no more than 5K rpm's.

    Another choice would be a GX160, you would have to change the motor-mount though to mount it vertical...Pat sells that setup. Much better and performance parts are available.
     
  6. Gbrebes

    Gbrebes Member

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    Hey Ray,

    I have had quite a bit of experience with both the GC160, the GC190, and the GS190. I have personally killed at least 7 of these different iterations of this motor.

    I too was drawn to the vertical orientation of the engine and the 5-6 horsepower. I removed the governor out of each engine, and I raced these engines, so I ran them hard, but I also killed all of these engines with a CVT clutch set up, which theoretically should have limited rpms. I broke valves, dropped into cylinder, dead engine. I bent valve stems, I threw a rod on one. I stripped the plastic timing gear, I lost timing belts. From my experience, this motor series can only be safely run for dependability with the governor in place.

    As for a replacement engine, CCC's suggestion of a gx160 is a strong choice, but if you are going to have to alter the motor mount to make an engine oriented slanted to be vertical, which you would need to do on a gx160, I would suggest going with the predator 212. Cheaper, lots of aftermarket parts, and tons of power. If not a predator 212, you could look into a built Briggs 5hp. It's a vertical motor.

    Good luck, and let me know if you have any more questions about the gc160-190 engines.

    Gilbert
     
    #6 Gbrebes, May 9, 2017
    Last edited: May 10, 2017
  7. Wheelwright Restorations

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    Thanks Gilbert and CCC
    Question on the GS GC 190. Is the valve cover bolt pattern the same as the GC 160? If it is I can use Pat's top mount with out modification.

    If the seats didn't get distorted and a valve will fix the GC 160 I'll just take it easy with it. If not I'll use a GC or GS 190 with a smaller rear sprocket.
    Any thoughts on engine oil. 20 50 too thick not splashing around enough?

    I'm reluctant to do a non vertical eng on this bike as I have all the time and $ into engine mount manifolds and hours removing unused engine bosses

    My next bike will likely have the HF 212. I want to do a spring seat full fenders and all the comforts a BTR lacks
    I love the look of the BTR but I'm over 6' and over 50 so it's not a easy ride. Perhaps I'll hire a kid to ride it around while I watch

    I've picked up a lot here. Thanks again
    Ray

    After this photo a 'sausage' type muffler was mounted horizontally
     

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    #7 Wheelwright Restorations, May 10, 2017
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  8. sportscarpat

    sportscarpat Bonneville Bomber the Salt Flat record breaker

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    Hi Ray,
    Cool looking build. Interesting feedback from all on the GC160. All news to me as I had not heard of problems associated with the GC. What I have found out over time is the cost to build out a GC160 bike is close to that of a 212.
    I make what I call my pedal bike frames, then step up to the beefier Sportsman 200 for the GX series engines. The pedal bike frames use clamp in mounts for the smaller engines and the frame comes standard with the Worksman INB rear triangle as a partnership with Worksman. These triangles use 110mm spacing and the INB dropouts. My concern with the bigger motors is mostly with the 110mm coaster brake hub being used with the bigger engines. I prefer to see the 135mm option on my pedal bike frames when used with the bigger GC160. This option is not available through Worksman but I offer it when the frame is purchased direct from my shop. The wider spacing and beefier dropouts allows the use of my drum rear hub and sprocket system. With your skills it would be easy enough to stretch your frame and move to the bigger hub for use with the GC190, but will not help with the engine problems you are having. Keeping speed and rpm down will certainly help with engine life. Unfortunately there are not many speed parts available for the GC line of engines. As far as oil, I just use good old fossil based 30 wt and always add a bit of high pressure additive zinc. Not looking at getting into the pros and cons of oil choices, just stating what I use in all my engines.
    Pat
     
  9. Wheelwright Restorations

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    Thanks for the reply Pat and thanks for all the advise during the build.

    Here are a couple of mods I did to your frame.

    I would like to learn more about your 135mm hub
    Do you have them available for sale?

    I think I'll leave this one pretty much as is, but use the new hub on the next bike one with fenders, lights, a trailing link front fork like one of the other members did.
    I plan to title it as a CB 175 honda I will use a few of the parts from the 175 but mostly just the vin
     

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  10. Potato_In_Exhaust

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    I don't think the GC160 are built for high RPM's....... with that said, if you want more power you should focus on torque. These engines are pretty much throw-away cheap engines that Honda developed to the lawnmower/water pressure/etc. market to cut cost with cheaper materials compared to the legendary GX line. I think the cam lobes on those motors are even plastic?
     
  11. Wheelwright Restorations

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  12. culvercityclassic

    culvercityclassic Well-Known Member

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  13. Wheelwright Restorations

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    I figured I couldn't go wrong with a Honda engine. How can you build a BTR and not want to beat the pi$$ out of it?
    I will say this for the engine.. it does look good!
     
  14. Potato_In_Exhaust

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    These motors can be modded, I swear I remember seeing someone turbocharged this motor on a pit bike or something...... saw it on Youtube.
     
  15. Gbrebes

    Gbrebes Member

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    Yes, I believe the valve covers are the same dimensions for both the gc160 and the go190.

    And yes, the motors do look the part with their vertical design, that's why I kept trying to work with them on my bike for 3 years or so. I finally got fed up with breaking them, so I rebuilt my frame to accept the 212 Predator motor tilted to be standing vertical.

    Gilbert
     
  16. Wheelwright Restorations

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    Thanks for the input.
    I won't stick with the GS for too long but I do have parts coming for this one.
    The valve train on the GS looks to be a week link.
    On ereplacmentparts the exhaust valves for the GX and the GC look very similar
    The GC one is $10 and the GX is $25
    If you could run the GX exhaust valve it would be a improvement. The head of my exhaust valve separated from the stem at speed
    Any one have a GX 160 exhaust valve to measure?
     

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