Broke crank arm? Loud noise in motor

#1
In need of some feedback please! I recently bought my son this mini bike and at first start I
Gently rode dowm the street and all of a sudden it stopped immediately and smoke came out of the top of engine. Now the pull started is very hard to pull start, but when I try n start it sounds like the pistion is hittiting the spark plug or some other part of the top of engine. I bought it off of a friend but he stated that he had the correct fuel and oil in the bike. Can anyone please help to diagnose the problem to FIXX this. Recommendations are very much apreciated on where to start. I'm mechanically capable for the most part on vehicles and dirt bikes, ect just wanted to get some.professiomal advice considering this is my first time.,working on small enhine as this. Thank you and God bless
 

Attachments

SAS289

Well-Known Member
#3
Take the rocker cover off and see if your valve train is still intact. Pull the spark plug and slowly pull on the pull start. Watch the rocker arms to see if anything unusual is happening.

If a valve broke off or the connecting rod went bad you may be looking at getting a new engine. Which Coleman do you have?
 
#6
Welcome. This is a great site. Have you removed and examined the spark plug? That's the easiest place to start. Are there signs of impact? Drain the oil. Do you see fragments of metal? Once you've confirmed the bad news, head on down to Harbor Freight and buy a new motor. Or maybe just skip those first steps and proceed directly to shopping. Remember to check online for a discount coupon.
 

old shed finds

Well-Known Member
#8
Wish we lived closer I have the short block in front of me.....
Harbor Freight will work but hope one is in stock.ours our sold out often... And early engine of your 196 is often a 5/8 crank..
So you would need a 3/4 clutch to fit that new 212 ...
 

Attachments

#9
...I have the short block in front of me...
Are there any marks on the piston crown or cylinder head and valves? You know, it takes just a few moments to pop off the side cover so you can peer into the crank case. I'm sure that everyone here wants to see inside now. Might as well remove the flywheel too.
 
#11
Are there any marks on the piston crown or cylinder head and valves? You know, it takes just a few moments to pop off the side cover so you can peer into the crank case. I'm sure that everyone here wants to see inside now. Might as well remove the flywheel too.
Thanks everyone I’m working on it now. I appreciate all the feedback. I will post pics here shortly
 
#13
Welcome. This is a great site. Have you removed and examined the spark plug? That's the easiest place to start. Are there signs of impact? Drain the oil. Do you see fragments of metal? Once you've confirmed the bad news, head on down to Harbor Freight and buy a new motor. Or maybe just skip those first steps and proceed directly to shopping. Remember to check online for a discount coupon.
No signs of impact on spark plug.
 

SAS289

Well-Known Member
#16
Just bought the 212 Barbour freight motor. Will the crank be compatible with the Coleman motor so I can use the original clutch.
You will need a new clutch. The Hisun engines have a 16mm crank and the 212's have a 3/4" crank.
 
Last edited:
Top