changed jet now it won't start

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KX_Larry
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Posts: 10
Joined: Wed Nov 07, 2018 4:19 pm
Location: Colorado

changed jet now it won't start

Post by KX_Larry »

Almost new RH50. Put on a Prima pipe, new rollers and new clutch spring. Put in a higher main jet and it ran ok for a half mile and was it was bogging coming up the driveway. I put the original jet back in and now it won't start.

I put in a new plug, which has spark, turns over fine, just won't get fire up.

What am I missing? thanks
KX_Larry
Member
Posts: 10
Joined: Wed Nov 07, 2018 4:19 pm
Location: Colorado

Post by KX_Larry »

success sprayed carb clean in there and got it started. still has a bog from the start so next step is pilot jet.

I live at 6,400 feet and have stock main jet. will mess with pilot and go down a size on main.

5g rollers and 1500 clutch spring
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Stanza
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Joined: Mon Jan 29, 2018 8:34 pm
Location: Chicago

Post by Stanza »

If you put on a prima pipe, you need to go up a size, not down. It will have an 82 in there by default, but with a prima you should be going up to a 90 or so, and see what your plug chop looks like. Don't go too lean, you don't want to overheat and lock the piston.
KX_Larry
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Posts: 10
Joined: Wed Nov 07, 2018 4:19 pm
Location: Colorado

Post by KX_Larry »

I had the 90 in and that didn't seem to work very well so I went back to stock.

I'll do some tests on the stock jet to see what the plug looks like. I figured with altitude and colder weather this time of year, the 82 would be a good place to start.

Scooter store said they don't change the jetting with a Prima exhaust, jut run stock. Said 90 was way too big.

I wish there was a standard chart for jetting, altitude and bike mods to give you a good place to start.

Exhaust go up X, altitude go down Y, big bore kit go X, etc.

My KTM 125 was easy to jet compared to a scooter. Don't even have to remove the carb, spin it, take out plug in float bowl, install new jet. 5 min and you are good to go.
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