80 Enticer 300 bog down at start

S

Stauby

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Dec 24, 2004
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Hello, I have an 80 enticer 300 that is having trouble starting. It will fire right up on the first pull, run for 10-30 seconds, then die. There is no unusual smoke volume or color. Sounds to me like flooding but carbs are a mystery to me so I am not sure. I siphoned out the gas and replaced with new high test. I have a strong spark in both plugs. I tore the carb down twice and cleaned all the parts and passages. The float and all needles and jets were replaced at the end of last season and still look great. During the second teardown I found black gasket material or grit at the input passage before the float needle. I thought this was the ticket, but disassembled everything and cleaned & blew out the passages to make sure- but it still acts exactly as before. I replaced the fuel filter and the fuel pump is keeping the filter full. Spark plugs appear wet. Plus, after I pull 3-4 times it will not relight unless I let it sit a while. So I'm still betting on flooding but I can't for the life of me figure out why. Any thoughts?

The next step in the manual is to check the timing. Since it fires up and sounds good for the 30 seconds should that be necessary? I don't mind trying but want to concentrate my efforts on the most promising activities.

Thanks for any advice. We're in Ohio and had a great snow and the kids are dying to take her out.

Merry Christmas to all.
Stauby
 

When you rebuilt the carb at the end of last season did the machine run ok?
 
Check to make shure the choke plunger is seating. follow the cable to the carb, and unscrew the brass nut underneath. it should pop up slightly. Pull out ,make shure it is moving freely, when you move the choke lever. clean out the hole it goes in and reassemble.
 
Nuts, thought we were on to something. I just checked and the choke cable and plunger moved freely. I oiled and sprayed cleaner in the hole just in case. Symptoms remain the same. I moved the choke fine adjustment throughout the thread range and it made no difference. Are there any other moving parts inside the choke that could hang up?

I appreciate all the troubleshooting advice. Any suggestions on what to try next?
 
Think I found it...

After removing the carb again and using ether in the intake manifold to check the cylinders while swapping plugs & caps I found that the I have no spark in the RH cylinder. Removing the plug and testing it on the engine block works fine. So, the RH spark plug cable will give a strong spark when it is in a stretched position but none in its normal position-that's why I couldn't find it when I checked the plugs before. There is a definite break and weak area in the molding around the base of the one in question. So, it looks like I need a new ignition coil assembly.

There is relatively little in my Clymer manual about this assembly. As far as I can tell, the spark plug caps screw into the ends of the cables, but the other ends look like they are molded into the coil body. Does anybody know if there are any serviceable parts on this assembly? Can the cables themselves be replaced?

Thanks again for the help. I'll keep you posted on what I find.
 
Take a razor knife and cut/chisel the molding off. try to get the wire insulation loose, cut the wire about an inch from the coil and try to get the remaining insulation off, and out of the hole. A pic works good. with the tail of wire sticking out , solder the new wire to it. use as little solder as possible. Put some two part epoxy on the new wire and glue it in. The extra wire will coil down in the bottom , no big deal. I did this on my old outboard, and it's be good for 5 years.
 
I found a replacement coil and swapped it in. Unfortunately it did not fix the problem and I am back to where I started. I know I have fuel in the bowl but still no sustained ignition.

The carb has me baffled. If I pull the carb back from the intake and have somebody pull the starter, shouldn't I see a mist of fuel coming out? I see nothing. Or is there engine intake vacuum that has to pull the mist out?

I also took off the starter pulley to look into the timing. It is capacitive start so there are no points to mess with, the timing was well within the expected area, and the screws were all tight.

I'll pull the carb one more time and go over it with a fine toothed comb. Any other suggestions? Is there anything I can check with the valves to see if any are stuck or broken?
 
Check to see if there is anything plugging the exhaust. The symptoms sound like that could be the problem. Engine will start until exhaust backpressure kills it. Good luck.
 
Are you saying the ignition is still cutting out? Sounds like your cdi box my be the problem. make shrue the wires/connections going to it are in good shape. It's common for these to heat up and stop working, then cool down and work again. You should do a resistance check on your coils, including the trigger coil, as this can cause the cdi box to go bad. call central snowmobile they should have the parts.
 
Sorry guys. I removed the exhaust and tried it with no obstructions and it is exactly as before. I REALLY appreciate the suggestions. Tomorrow will be in the 40's and it goes up from there, so I missed this window. I'll get it in the shop & have it ready to go for the next one. It just bugs the heck out of me trying to figure out what the heck it could be!
 
check for signal on wires coming out of bottom of motor. i have heard that they break inside the insulation at or just past the rubber isolator where they come out of the motor underneath. guy that told me about it took 3 weeks to find this on his and then went and checked his cousins with no problem yet and it was starting to do the same thing.
 
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