Fouled Plugs, Chain Breaking

Discussion in '2-Stroke Engines' started by bigkev81, Aug 2, 2016.

  1. bigkev81

    bigkev81 Member

    Hey guys,

    A while ago I bought myself a motorized bicycle with an r80 engine kit installed.
    Was purchased fully assembled and brand new from the shop.

    Anyways, while running the motor in, I found that it constantly fouled up spark plugs which I changed 3 times in its short life. Also, the chain broke just as often.

    On my last ride, the chain snapped, the bike bucked and I had a nasty crash in the middle of the street. Luckily it was a quiet cul de sac with no traffic at the time.

    That was 3 years ago, and the bikes been sitting in my garage ever since. I've always meant to fix the bike up again, but have lost contact with the guy who used to re-do my chains for me.

    I am wanting to have a go at fixing it myself. Can anyone out there shed some light on what may be going on with my bike? I haven't ridden it much, maybe gone through less than half the petrol tank.

    Why do the spark plugs get fouled so often and why does the chain keep breaking?

    Kev :)

  2. crassius

    crassius Well-Known Member

    fouled plug is probably bad mixture in mixing oil & gas, or in carb being too rich - no biggie to sort out

    chain breaking means something wrong with sprocket alignment or incorrectly tensioned

    all info you need is here on the board
  3. bakaneko

    bakaneko Active Member

    Yeah, and you need to clean and oil your chain periodically. It will extend the life of your chain and keep it from reaching that critical stretching and breaking point. I like to do it ever 200 miles. WD40 and toothbrush to clean and just regular oil to lube or if you can get actual motorcycle chain lube...
  4. bigkev81

    bigkev81 Member

    Thanks guys.

    Now the fuel tank is almost full and has been sitting for a couple years. Should I drain the tank and start again? Or should it still be okay.

    Also, I can't remember what ratio to mix the petrol and 2strokeoil. Any advice?
  5. bakaneko

    bakaneko Active Member

    definitely drain the tank and safely discard the petrol. the ratio is 32:1.
  6. Steve Best

    Steve Best Well-Known Member

    Try good synthetic oil at 32:1 to keep from fouling.
    Chain alignment is critical for chain life, as is a small amount of slack.
    That said, cheap chain is garbage.
    I am having good luck with Giant brand BMX (410 or 1/2"x1/8") bicycle chain. Light, cheap, strong.
    Make sure all your (esp drive) sprockets are under 0.125" wide to use it.

    Cleaning? I pull my chain off, slosh it in a coffee tin of lamp oil (kerosene) and hang it to dry.
    Next day I lube it up with my favourite lube of the day. Have not found a perfect one yet.
    Chainsaw chain oil, soaked the chain in it overnight in a coffee can. Very cheap, effective.
    Beeswax, often from a toilet seal, heated up in a pot, often with additives like alox bullet lube or moly or graphite.
    Soap, either heated and melted into the links, or a liquid soap like dish detergent soaked overnight.
    Dry lubes like moly, teflon and graphite applied with a solvent and allowed to dry.
    And of course, all the commercial preparations, sprayed or soaked, heated or cold.

    All worked about the same.
    Maybe the soap and dry lubes needed more frequent applications but worked better in sand.
    None would make a cheap chain last longer and a good chain worked with them all.
    When MX'ing with a non-"O"ring chain in sand and grit, it was practice to remove, clean and lube the chain every night.

    This was all from 30 to 40 years ago. Since "O"ring chains came out I "ride and forget".
    Might clean and lube it before a big run, but "O"ring chains are hard to remove.
    This might be fertile area for study...

    Last edited: Aug 3, 2016
    Diamond Back likes this.
  7. It's possible that your sprocket teeth may need to be brought down a bit, if they are too big and pointy? They may Mr catching the edge of your chain.
    I had a similar accident buy the chain just broken. Twisted, & wrapped aroundy rear sprocket. Hzf to pedal home . My problem was that the front engine mount was off by s FRACTION! Wich caused a clicking sound (IT WAS SLIGHTLY OF CENTER) so. I got a billet mount smd all was better.
    Accept my soiled frui-o-da-looms that scared the sh*t out of ME.
    P.S. I USE a 415 chain.
  8. bigkev81

    bigkev81 Member

    Thank you for all the helpful info everyone.

    I have ordered spare parts which should be delivered tomorrow. A 415 chain, and an air filter. My mate pulled the bottom cap off the filter 3 years ago and its been sitting like that so long, it will no longer close.

    Both tyres were flat but luckily they reinflated with a bike pump.

    As for the chain breaking, everytime it happens the chain seems to get stuck in the engine. If you look at the sample photo, the chain tends to get bunched up going around the top leftcorner.


    And everytime the chain has broken, it has gotten stuck in the same manner.
    I am thinking that maybe my chain has too much slack in it?
  9. That's kinda what happened to me with my chain except mine was rubbing it on the seat post motor mount so I took a grinder and took a little off this the motor mounts just the hair. However that didn't solve the problem it was my dad like I said off kilter just a little bit so I got a big mouth and straightened it out. Like I said the front engine mount was off by just a fraction which made the engine off to the one side just a little tiny bit and that's enough to make it cockeyed, and grab the teeth on the rear sprocket and get caught up. And snap good luck to you mate
  10. P.S. I Also switch to an idle arm tensioner chain tensioner. It's a crescent-shaped piece of metal that goes Across the frame on the rear at the wheel to both bars
  11. bigkev81

    bigkev81 Member

    Damn Damn damn! lol
    Got my order delivered this morning. And the Air filter I ordered. But I didn't need one. I meant to order the inline fuel filter, lol.

    So placed another order for the fuel filter, as well as some spark plugs, just in case these ones are fouled. I don't know how easy or difficult it is to clean and regap them lol, I'll have to learn those skills.

    Unfortunately because the parts vendor is away, he can't send my order until Tuesday, which means I won't recieve till wednesday next week! :(

    Do you think as a temporary fix, I can glue the bottom cap back onto the fuel filter? Should I use superglue? Epoxy? Silicone? Liquid Nails? Gorilla Glue? lol

    Thanks for the info so far guys! :)

    WINDY CITY BOB: I have seen those tensioners before, and I like it! Will have to find a supplier in Oz, or who ships to Oz.
    I like your nickname. Is it a reference to Chicago? I'd love to visit the US, maybe even migrate, as long as Donald Trump doesnt win, hahahah

    As a thanks to all those who have been so helpful and patient for me, here is some pictures of my cycle. I hope you guys like it.
    I took the front wheel guard off when i first got the bike, am thinking of putting it back on.

    Also wanna get a rear rack to stow away my bag, some tools plus whatever else. I ordered one 3 years ago, but it didn't fit, didn't agree with my bikes setup.

    Well, I am now off to watch some netflix, and will probably have a go at putting the new chain in later tonight.

    Kev :)
  12. Yes windy city is a nickname for Chicago.
    Zamm Also you can get an inline filter and an auto parts store or small engine store like a Lawn mower fuel filter or something along the lines of that or a small motorcycle filter in any kind of auto parts store. I don't know what you said they're available but that's what we have here.
    If you visit Chicago let me know hit me up
  13. bigkev81

    bigkev81 Member

    Thanks for the tip WCB, will check them out this weekend.

    Oh yeah, I've got a couple spark plugs which fouled with prolly less than 10kms on them. I'm gonna try giving them a clean.
    If I need to re-gap the plug, what is the measurement I need to regap it to?

    Kev :)
  14. I honestly don't know,I just buy new ones from autoparts store.
  15. I keep extras in one of my workbenches
  16. Diamond Back

    Diamond Back Active Member

    Steve my man,,whatz up buddy... i been away for a week so i missed somethings,,,lol,,,,lol
    hey STEVE !!!! TRY THIS OIL, I AM LIKE YOU ALWAYS LOOKING FOR THAT AWESOME LIQUID THAT DOES EVERYTHING GREAT .. ITS CALLED*******MARVEL's MYSTERY OIL************* its in auto stores red,white,black container liquid looks like trans fluid...but STEVE this stuff is great great stuff,,, i have used on everything, cleaning best degreaser out there to where 1 one cap full in your gas tank will rebuild your engine in 2 days...LOL But its good stuff !!!!! how ya been ? i gotta finish my bike upgrades and paint,,, got my 2004 Suzuki RM 85 pipe welded on finally... but i havent fired it up yet or riden,,, and I swear by now days to only do one mod at a time so I can see and now what differences were made where....

    Before I would do like 5 things and something go wrong or is wrong you have a bitch of a time telling what is what,,,,uugggggggggg!!!!!!!

    one thing at a time from now on !!!! what you think ?????
    Steve Best likes this.
  17. bigkev81

    bigkev81 Member

    Okay guys, tomorrow I'm expecting delivery of a few things I've ordered.

    One of the items is a bike chain tool.

    When it comes to closing the chain, do I need to use the master link clip?
    Would the chain be stronger if I forgot the master link and just used the tool to close the chain?