Hard to start - need advice

I have a Tomos with a 70 cc kit. It is always very hard to get it started. Sometimes it just won't start. I changed the gas (new) and installed a new gas line. Yesterday, after several kicks and some starting fluid it started and I ran it for 7-10 minutes. Today it won't start. It there a best combination for starting between choke (on or off) - starting fluid (or not) and giving it throttle (or not) that is best?

Re: Hard to start - need advice

Overpriced Parts /

Since it’s not stock it’s probably not Timed, tuned, jetted correctly Or carburetor jets/holes are blocked fuel filter or petcock blocked or could have seize piston or cylinder Damage, you may just need a new plug,

Post more info of your setup on the bike,

Re: Hard to start - need advice

Yeah that bike isn't tuned. Hopefully you diddnt damage the engine.

Re: Hard to start - need advice

Here's some moreinfo. It's a 1993 Tomos Golden Bullet too tank. A35 with. 70 cc turbo kit (piston, head, carb and biturbo exhaust. Getting the timing right was tough but a good mechic (Chris K) got it going. That was a copule years ago. I've put 600 miles on the 70cc . It's been sitting for over a year.

Re: Hard to start - need advice

Clean the carb , meticulously . ;)

Re: Hard to start - need advice

Yup sounds like a dirty carb.

Re: Hard to start - need advice

^yes, if its a sha carb, and its been sitting for a year, it tends to plug up that idle hole under throttle slide. important to run a fuel filter inline as well. i know its overkill but it is visable. check fuel flow, clean carb, points or not, if so clean, then compression.

if its cold in cinci, choke it for a while.

Re: Hard to start - need advice

♣Slew Foot♣ /

Nope kitted Tomos are cold blooded.

Check vent fueline length and dia it is flooded and then its a bitch.

Choke on fuel off. Start disengage choke when it starts dying. It may be immediate.

Gas type. Winter blends screw jetting and ratios all ways deal with known quantities. You can instead of rejetting play with the ratio it takes a long time to get rite...fu gramma nutzis...

Re: Hard to start - need advice

The carburetor is an Arreche Amal 15mm. I will take it apart and clean it. Should I do anything with the air filter screen? It looks like it is made with two metal mesh screens with a thin foam in between. The foam looks like it has some deterioration and gaps.

Re: Hard to start - need advice

not familiar w that carb but sounds cool Arecheeeee. Id remove n replace foam.

Re: Hard to start - need advice

I cleaned the carb very carefully including the main jet and adjustment screws. Changed the fuel line and install a new inline fuel filter. Gas is new with 50:1 mixture. Cleaned the spark plug. Have good spark. Spark plug was black and had fuel on it.

Still won't start. Sometimes it rumbles a couple times like it is going to start but doesn't. Any thoughts on next step?

Re: Hard to start - need advice

I installed a new NGK b7hs spark plug. It has a good spark, cleaned carb, new gas, new fuel line and filter, and still wont start. What's next to check? Could it be the timing or points/condenser?

Re: Hard to start - need advice

could be, try squirting some premix down the plug hole with petcock off. does it fire? if not then compression, tighten head bolts, clean points, disconnect kill. wirr

Re: Hard to start - need advice

Update: I got the moped running tonight. Over the past couple weeks I cleaned the carb, got fresh gas, new fuel lines and filter, and new spark plug. To start it I had to give it full throttle when I kicked it. Does full throttle seem odd? It crackled and popped for a while but then idled well then ran ok. A few hesitations mixed with good acceleration when riding. I am leaking some oily black fluid at the exhaust pipe. Maybe too rich?

Re: Hard to start - need advice

It is definitely not tuned correctly regardless if it was at one time. You are probably flooding out from a dirty float needle/seat if you have a lot of black oily fluid dripping out the pipe. Gas is leaking down through the cylinder and into the exhaust. Everything you described points to that. Sitting for a long time, ran but now hard to start, having to hold the throttle wide open to start, takes a while once you start it to run decent, etc. Having to hold the throttle wide open to start is your engine needing and trying to get more air to lean out out the mixture.

Take the carb back apart again and re-clean everything and really focus on the float valve seat. The tiniest little particular will cause it not to seat and gas will seep into the engine when sitting . Never ever refuse spark plugs when trying to sort or or diagnose these kinds of issues. Often, plugs that have been fouled due to flooding or a rich running engine may be still causing issues too but may look fine to the human eye.

Re-clean the carb

Put in new plug

Clean and gap points.

Check timing

Clean air filter

If possible, clean out exhaust

Start engine.

Run for as long as you can at high speed to clean out the engine...do not let it sit and idle for more than 15 seconds at a time.

If running good now, you win

If not, start the rejecting process by dropping a size. You can also experiment with the air intake flow by removing the filter temporarily and see if that made a difference.

Re: Hard to start - need advice

∆∆ he meant rejetting not rejecting.lol

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