Realy hard to pull start 49cc 2 stroke

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Poboy kartman

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4 stroke engines have valves, a cam, and timing.

2 strokes don't, your hard cranking problem is hydrostatic lock from fuel in the combustion chamber.

Poboy out.
 

maxpower49

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I'm with poboy and rail rider, hydro locking from flooding or to throw my own theory in it could possibly be a sheared timing key causing it to spark at the wrong time and jerk the pull cord out of your hand. Try unplugging the spark plug and pulling it over a few times with no spark if it still gets really tough to pull then it is flooding if it pulls easily with no jerking then it may be a partially sheared timing key.
 

pearl111

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With the plug out I looked with a flash lite down in the plug hole and WOW there is a lot of caked on blacked stuff carbon I'm gessing? If the cause is to much carbon build up is there something I can put down in there to get that out with out taking the motor apart? If not what would be the best way to clean that out? thanks for all the help and comments.

---------- Post added at 07:48 AM ---------- Previous post was at 07:39 AM ----------

I just thought off something could I spray carb cleaner down in the hole without doing any damage?
 

ML-TOYS

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With the carb. off the motor and the plug dry I also used air to dry plug hole. Pulling the cord was really easy. With the carb still off the motor I put the dry plug back. Pulling the cord was still very hard to do. In the past I had a 47cc and 49cc pocket bikes though they were never this hard to pull. I believe the person who gave this mini quad, took the pull cord cover off to replace the cord. Is it possible there could be something wrong or broken in this area? thanks for any help or suggestions.

Yeah, check direction of pull.
Probably reversed
 

Poboy kartman

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If you're seeing carbon deposits on top of the head, then theres even more you can't see on the head.

I don't see anyway other than pulling the head.

(There are ways like pouring water in while running) and some concoction another member has touted (I forget what), but ...realistically, it needs a good physical cleaning and maybe a ring job.

---------- Post added at 08:27 AM ---------- Previous post was at 08:23 AM ----------

Yeah, check direction of pull.
Probably reversed

Good idea, I think those pull cord assemblies are like $6 complete, but it takes a week or two to get here from China.
 

itsid

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....
2 strokes don't, your hard cranking problem is hydrostatic lock from fuel in the combustion chamber.

Poboy out.

frankly even hydrostatic lock is difficult on a two stroke.. since they all "vent" the cylinder against the crankcase at some point..

so unless the cylinder is pointing downwards and/or somebody thought it might be a good idea to fill the crankcase itself to the brim with oil... I don't see it hydrostatic lock happening tbh.

frankly.. it's more likely there's a mechainical issue or some part just dropped into the cylinder (broken leaf from the reed valve or something) or the crank is seized (bent/broken) a pistonring slipped for unknown reason.

that engine need to be disassembled IMHO to find and fix the issue.

'sid
 

pearl111

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I guess I might attempt to pull the head on the 49cc for cleaning. When I attempt this (first time doing this) do I need to be aware of parts flying off and out off the head? Hopefully I can get it apart and cleaned up. Any one know the ft lbs for putting the bolts back? I only have ftlbs torque wrench.

If I mess this up I'll cut the frame and try to stuff a pred. 212 hemi in it that's sitting on my work bench. I know I'll have to upgrade the back axle, sprocket, wheels and such. This will be my next project if I can't get the 49cc mini quad going. Does any one know if there are any mini quads with 200cc or more? If so that might give me some guide lines to follow.
 

Randy H

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I haven't personally worked on an engine like yours. But I can't imagine any spring loaded gizmos will come flying out.

Did you try pulling it with the ignition off?

Might save time by cleaning the carb while your at it too.
 

Randy H

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Assuming your acorn free. I'm guessing you found lots of carbon buildup. Hopefully, done deal.

Not likely you have a sheared key/timing issue.
 
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