Spark Plug

[Johanv]

Hi , I've a Gasgas300 2003 model 2stroke- replaced the plug for a 3rd time now in 3 weeks- bike starts easy and then just dies- take the plug out and put in a new one and starts first kick again- old plug not even 1 hour old but wet when taken out, is this due to fuel problem and what plug should it be? I put in a NGK BR8EG- is this the right plug? Also want to ask- the bike is strong from 3rd gear but 1st and 2nd gear not running smooth and strong but more of a spatter- is this fuel or reed valves? Thanks in advance

 

[Anders]

Hi , I've a Gasgas300 2003 model 2stroke- replaced the plug for a 3rd time now in 3 weeks- bike starts easy and then just dies- take the plug out and put in a new one and starts first kick again- old plug not even 1 hour old but wet when taken out, is this due to fuel problem and what plug should it be? I put in a NGK BR8EG- is this the right plug? Also want to ask- the bike is strong from 3rd gear but 1st and 2nd gear not running smooth and strong but more of a spatter- is this fuel or reed valves? Thanks in advance

I would guess it's jetted a tad too fat, or that you ride it less aggressively (keep the motor running closer to idle / low throttle) than the previous owner. Or both. I experienced the same when I got the 2006 some years ago.

Read the jetting threads, check your jetting. Being a 2003 model, the carb may be worn, which does not help when you try to find the optimal jetting for your riding and conditions.

 

[SS109]

Plug is correct. The jetting is more than a tad off if you're killing plugs that fast. What is your current jetting? Have you checked the float level? If PWK carb, is the jet block gasket good?

 

[swazi_matt]

plug is correct but if you're battling with jetting it will be much cheaper to test with a BR8ES

 

[Jacob 'Berg]

I would also check the float level as well if you have not done so.

Check to make sure you are not burning gear oil due to a leaking crank seal, which can cause plugs to foul and the bike to run like crap.

 

[Johanv]

Spark Plug Issue

Hi, Thanks for the many replies- will have a look at the jetting etc.and when the problem is found will post my reply.

 

[Johanv]

Spark Plug Issue

Plug is correct. The jetting is more than a tad off if you're killing plugs that fast. What is your current jetting? Have you checked the float level? If PWK carb, is the jet block gasket good?

Current Jetting is a 38/170 - tried a BP6RES plug and it actually lasted for 2 weeks without issues, now this morning fouled the plug again after startup- bike started- ran for 3 secs and died, what is an easy way to check if the crank seal is blown?

 

[Doc Brown]

Current Jetting is a 38/170 - tried a BP6RES plug and it actually lasted for 2 weeks without issues, now this morning fouled the plug again after startup- bike started- ran for 3 secs and died, what is an easy way to check if the crank seal is blown?

This spark plug is far too hot. Changing the spark to a hotter one masks the problem but does not cure it.

Which oil (brand) and which mix are you running? Which fuel (brand and octane number) are you currently running?

 

[Johanv]

Hi, running a 50:1 ratio on 95 unleaded fuel. Read a reply that over oiling an air filter can also result in killing the plug- had a look at my air filter and I think I was a bit eager on the air filter oil spray. When I removed the carb I also took out the reed block-its a boyesen block and the previous owner tried to modify another brand reed valves in there with some modification on the holding plate- the reed tips was also open- will replace them. What is the correct fuel? Should I rather use 93 unleaded?

 

[(F5)]

I had a bike with a weak ignition that would kill plugs. Try a new plug cap, or better yet a coil and cap off another cdi ignition bike.
The stators themselves do fail but I'd expect more erratic behavior.

 

[Doc Brown]

Hi, running a 50:1 ratio on 95 unleaded fuel. Read a reply that over oiling an air filter can also result in killing the plug- had a look at my air filter and I think I was a bit eager on the air filter oil spray. When I removed the carb I also took out the reed block-its a boyesen block and the previous owner tried to modify another brand reed valves in there with some modification on the holding plate- the reed tips was also open- will replace them. What is the correct fuel? Should I rather use 93 unleaded?

No, stay with 95 unleaded and 50:1 but get a correct spark plug.

 

[Johanv]

I will give it a shot- thanks

 

[Johanv]

Spark Plug Issue

Well, I replaced the reed valves with that of a Banshee ( Carbon Fibre) and now my bike runs like a beast. Will check the plug cap if it fouls again and also be a bit leaner on the hand when applying air filter oil. Thanks for the replies and advice.

 

[motorhead]

Singletrack/Low RPM'S = BPR7ES
P - projected tip, 7 - one step hotter than 8, =Less plug fouling

 

[Doc Brown]

Sorry, but fighting plug fouling with a hotter spark is not the right way. If you have toothache you can take a painkiller, it may help. But it is not the final solution.