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baja only starts when i put 2 cycle oil iin piston

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Old 01-05-2009, 01:12 PM
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selena1718
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Default baja only starts when i put 2 cycle oil iin piston

hi,just put a new big bore kit in my baja,i have spark,i have a new plug,ciol gap is good,ive tried numurous things,the only way it starts is if i put a littlle 2 cycle oil in piston,and it only runs for a few seconds,does this mean i have low compression,and how do i fix it,thanks,oh buy the way ,i do have the piston arrow facing the exhaust port,.
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Old 01-05-2009, 02:21 PM
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speedy.d
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Default RE: baja only starts when i put 2 cycle oil iin piston

i just had a similar problem, it turned out to be a bad head gasket,if i were you i would check for air leaks.check out the engine troubles thread there is some info that the guys sent me to help me out
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Old 01-05-2009, 03:34 PM
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Default RE: baja only starts when i put 2 cycle oil iin piston

Could be with new piston & ring..there not seated yet.. so the inside cylinder walls are still polished smooth..You will have to add a table spoon
of 2 stroke oil to get started..to form a seat to get started....You will have to re set you carb back to factory setting and go from there.......
any changes made..like exhaust pipe,gaskets,different carb..you always have to go back to factory carb settings ...Hope this helps..AKASlawhammer
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Old 01-05-2009, 04:17 PM
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SAVAGEJIM
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Default RE: baja only starts when i put 2 cycle oil iin piston


ORIGINAL: selena1718

hi,just put a new big bore kit in my baja,i have spark,i have a new plug,ciol gap is good,ive tried numurous things,the only way it starts is if i put a littlle 2 cycle oil in piston,and it only runs for a few seconds,does this mean i have low compression,and how do i fix it,thanks,oh buy the way ,i do have the piston arrow facing the exhaust port,.
When you installed the new head and gasket, did you check you squish height? It sounds like you have way too much squist height, and thus a very very low compression ratio, and putting in 2-stroke oil to reduce that compression ratio by temporailiy causing a hydro-lock situation that actually temporarily establishes the correct compression ratio, at least until it all burns away.

If your squish height is too much, you must get a thinner gasket. I would get gaskets of different thicknesses so that you can play with them to get the correct squish height.
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Old 01-05-2009, 06:32 PM
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selena1718
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Default RE: baja only starts when i put 2 cycle oil iin piston

hi savagejim,thanks for your reply,i used the gasket that came with the kit,got it from ddm,should i maybe get one of those copper ones,what exactly is squish height,thanks
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Old 01-06-2009, 08:21 AM
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clubin
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Default RE: baja only starts when i put 2 cycle oil iin piston

You need to take a piece of solder bend a 90 on it and put it in the spark plug hole and flatten it till you can turn the crankshaft with the piston squishing it the last little bit and measure the thickness of the solder that is your squish.
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Old 01-06-2009, 07:09 PM
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Default RE: baja only starts when i put 2 cycle oil iin piston

If i were to bet, it would be a 28.5 kit? Some of them need a little help to get the ring seated. The oil seals the ring to the piston, for a short while. Your ring may be stuck in the piston groove. Did you oil teh groove before installation?
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Old 01-08-2009, 08:16 AM
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Default RE: baja only starts when i put 2 cycle oil iin piston

hi ramtech,no i didnt oil the groove,im assuming i should,i dont understand by what you mean by the ring could be stuck in the groove,as i said,im new to this,thanks
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