I just built a 727 Raptor with 12 to 1 compression. If the piston stops top dead center it wil NOT turn over. Its a pain in the *** to bump back and forth to get started. Is there an upgraded starter I can get??? Any help would be appreciated.

JK

 

thats the problem with high compression 727 kits. is your decompression mech working on your cam or is it gone? the starter is not the problem. its the battery. if its a cheap one it wont work. if its a yuasa thats factory that has just enough amps to start a stock one in the cold. try boosting the battery with a charger when starting. do not use a car battery or jump start it with a car. they have too much amps and will damage your cdi.
when you get more run time on your motor it will get better at starting. but do the charger boost to get it going.

 

thats the problem with high compression 727 kits. is your decompression mech working on your cam or is it gone? the starter is not the problem. its the battery. if its a cheap one it wont work. if its a yuasa thats factory that has just enough amps to start a stock one in the cold. try boosting the battery with a charger when starting. do not use a car battery or jump start it with a car. they have too much amps and will damage your cdi.
when you get more run time on your motor it will get better at starting. but do the charger boost to get it going.

 

sounds like there is no decompression

 

sounds like there is no decompression[img]i/expressions/face-icon-small-wink.gif[/img]

 

I have the stock battery which is brand new. Should I get an aftermarket battery? Is there a heavier duty starter too? I put it on the charger and put it on boost and still nothing. I called the guy who did my motor and he told me to put it in 2nd gear and bump the bike backwards. I did that and rolled the engine back a hair and it fired right up. As far as decompression mech, I don't know anything about that. My Raptor is a 2005 with 727 kit, stage 2 hot cam, over size valves, and hd springs. I rode it for the first time after getting it fired and it is definately a rocket. I have an 01 that was pretty much jetted w/ stage 1 hot cam. I thought it was fast until I rode this one. WOW!!!!

 

1st, I would find out if the decompression mechanism is still there (ask whoever built it)

if it is,,,,it sounds like it is not alligned properly

search 'cam' and 'decompression',,,,,there are a few threads related to this,,,,,and specifically the decompression problems on aftermarket cams

 

You can also install a batter from the yamaha grizzly for more cranking amps. But my guess would be that you have a malfunctioning or non-existant decompression mechanism.

 

just out of curiosity how much did that 727 kit run you?

 

I think I paid $350 for the kit and I bought it on EBay. The guy I bought it from has another kit listed right now. The only thing about doing the 727 that I did not reallize was you have to split the case and have the cases machined in order for the 727 sleeve to fit. I have an extra set of cases that have been machined for the 727 sleeve if anyone is interested.

http://cgi.ebay.com/ebaymotors/ws/eB...sPageName=WDVW

Jason Kirby
jtk23@insightbb.com