i have had pre 65 and twinshockers for many years.... so i decided to try a gas gas and i bought a 1994 JT 238cc contact just to play on.

 

Starts second kick every time from cold.... it runs for 10 to 15 seconds then sound like its starving and then stops and wont go again..... I then check plug.... no spark.... fit new plug NGK BP5ES and away she goes with good spark.  She will run ok for an hour   no problem.   next day i start it and back to run for 10 to 20 seconds.

 

What is killing the plugs and why??????  i am baffled!

 

I have tried the old used plugs in other bikes and no good at all.

 

Anyone had a problem like this?

 

 

Thanks in advance for any help

 

Chummy

Not sure what your problem is but NGKs are notorious for failing after being oiled. I prefer ngks to champions, but when a champion oils you could always clean it and its fine

Years ago I had a similar problem on a (believe it on not) TY 175. it would start easily and run for about a minute,(enough time to get to the first gate) plug dead. 5 plugs later, (slow learner, and all available plugs stuffed). I went and got a platinum plug and instantly no more problem.

As to why, Sorry no idea, but I'm guessing that maybe combustion created a deposit that shorted the plug, and the platinum one ran hotter/colder and prevented this happening.

These days I would go for an iridium plug.

Years ago I had a similar problem on a (believe it on not) TY 175. it would start easily and run for about a minute,(enough time to get to the first gate) plug dead. 5 plugs later, (slow learner, and all available plugs stuffed). I went and got a platinum plug and instantly no more problem.

As to why, Sorry no idea, but I'm guessing that maybe combustion created a deposit that shorted the plug, and the platinum one ran hotter/colder and prevented this happening.

These days I would go for an iridium plug.

Same here on my Greeves running a brand new electronic ignition, it would do 2 laps of a trial then pack up, swop to a new one (ngk) and would do the same, swoped to a platinum one and it's been fine since

Edited December 8, 20169 yr by hulmie

i have had pre 65 and twinshockers for many years.... so i decided to try a gas gas and i bought a 1994 JT 238cc contact just to play on.

 

Starts second kick every time from cold.... it runs for 10 to 15 seconds then sound like its starving and then stops and wont go again..... I then check plug.... no spark.... fit new plug NGK BP5ES and away she goes with good spark.  She will run ok for an hour   no problem.   next day i start it and back to run for 10 to 20 seconds.

 

What is killing the plugs and why??????  i am baffled!

 

I have tried the old used plugs in other bikes and no good at all.

 

Anyone had a problem like this?

 

 

Thanks in advance for any help

 

Chummy

Your old ignition is breaking down and can't deal with the load , get a iridium plug and/or a new coil and lead.

 Aka ... The plug is never getting to temp to clean itself .  And make sure all of your grounds ( motor mount bolts too .) Are good and clean .

Edited December 9, 20169 yr by axulsuv

I had a husky 250 that had the same type of problem, for me it turned out be the ignition coil dying when it got hot and started to breakdown and the bike would die.

I had similar problems with frequently fouled plugs. Also the engine dis not run well

There where two issues.

Issue #01:

It turned out that the engine did not got enough air due to a hole plate mounted inside the air box provided to little air flow. I replaced it against a much less restrictive (in terms of air flow) plate which is more like a mesh and the engine worked much better

The second issue was the carb and the float valve it worked good while the engine was.off and the bike stood on even ground. But once the engine was started and the bike stood just a bit up or downhill the carb flooded itself and the cylinder causing a much to rich air gas mixture. The issue was a float valve (brand new) that was about 1mm shorter then the old one.

 

Anyway I would check the air filter if it's not clogged and too the level of the floats also if the seals to the carb are still working here the seals to the:

- choke lever (bottom),

- choke jet, o-ring,

- float valve, rubber cone,

- idle and mixture screw the little o-rings inside.