Hotter Spark Plug?

[kendunn]

Originally Posted by marjastaja

So if I run mx, I would be able to go for a BR9 plug to run engine cooler?

Does not make your engine cooler, it means your plug doesn't get as hot. If you run wide open all the time like in an open MX or desert race you may want to run a colder plug to prevent pre-ignition.

[Todd5774]

Think everyones getting the wrong idea here..

nothing wrong with my jetting, bike pulls cleanly at any rev, with no hesitation or bogging, dosent foul a plug.

what i was asking was on the very few occasions that i race in tight woods where you are not getting into the power, i asked if it would harm the engine to run a hotter plug for that race rather than go to the hassle of changing my jetting.

Im in the UK where we havent got lots of space to ride so tracks tend to be very tight and twisty, and being as i dont race that often my bike is not set up for that particluar enviroment, mine is set for trail riding.

[kendunn]

Originally Posted by Todd5774

Think everyones getting the wrong idea here..

nothing wrong with my jetting, bike pulls cleanly at any rev, with no hesitation or bogging, dosent foul a plug.

what i was asking was on the very few occasions that i race in tight woods where you are not getting into the power, i asked if it would harm the engine to run a hotter plug for that race rather than go to the hassle of changing my jetting.

Im in the UK where we havent got lots of space to ride so tracks tend to be very tight and twisty, and being as i dont race that often my bike is not set up for that particluar enviroment, mine is set for trail riding.

What did you mean when you said you went through 8 plugs if it doesn't foul a plug?

[Todd5774]

Dosent foul a plug in normal operation.. Had the same plug in the bike for 6 months no problems, the problem came from one particular race in a wood with very deep ruts where you couldnt get into the power.

And my question originated from a riding friend, who suggested changing to a hotter plug just for that particular race.
I was just wondering if it could be done with out harming the engine, as i dont particulary wish to mess with my jetting for one 2hr race.

[kendunn]

You can go one stop hotter and be fine, but I still bet you have a jetting issue somewhere around 1/4 throttle. It shouldn't foul 8 plugs in 2 hours. Start here-http://www.keihin-us.com/am/_media/pdf/slide_valve.pdf

[swazi_matt]

so if you ride mostly tech stuff where you are hardly off the pilot jet you could go for an 8 or 7? I have noticed that often on the riding i do i come out of a long tech stuff onto a track and open up the gas and the bike splutters a bit (like a cold engine) before it kicks into powerband

This caused me to flip at the last race because i cam out of a tight section to a v steep climb with a short run-up so i opened it up at the bottom but the first few meters of run-up were used up by splutter and i was trying to get going on the slope. second attempt was fine

[swazi_matt]

Also GG recommends a BR9EG for my bike, I cannot get these at the moment as the bike shop is out of stock, what would be the implication of running a BR9ES? or BR8Es if i decide to go slightly hotter

[GMP]

Hot plug is a bandaid for bad jetting. I run the basic cheap BR8ES with good jetting and 36;1 mix, in very technical stuff, and have no issues. I could run the plug for an entire season if I want, I just pull it occasionally to check.

[widebear]

If you want to run the correct heat range but want a plug that is less prone to loading up, consider running a projector nose plug. NGK BPR8. It will tolerate poor jetting and low speed fouling much better than semi shrouded types.

[fabulous furry]

yes i did that too on my 300 i see you leave in a hot country like me and i was so fed up with the jetting around problem and went for a hot plug 6 but strange enough i could not get high rev power.i have 35 pilot and 168 main with cck needle.i think i will try the float level.my 250 never had an isssue like this.