125 hotter plug?
- Thread starter spooly
- Start date
If I saw that color on a plug taken from what some call a "throttle chop" type of test I would call your bike running pretty rich. if it is just a removal after 4 hours of running a 125 I wouldn't draw the same conclusion. it looks decent from a jetting standpoint. in the how to section here I notice 'chokey' reposted his jetting advice from when he was known as "spanky". It is probably about as good a jetting primer as I have seen. I wouldnt miss reading it.
Some things I found: Plugs for weather or jetting (weather and jetting being closely related) are not a good "fix". all that said they can be a bandaid, if you know how to use bandaids. Eg: you are going to ride from 2000 feet to 8000 feet in one ride. Lots of downhill coasting. I carry a hotter plug with me as a replacement if my rig doesnt like the big change in jetting requirements. Just know you can't hold the throttle on for as long as you could with the colder plug without creating a spot that may be hot enough to bring on detonation and preignition.
Eg. I am going to do a flat out run on a dry river bank that is double digit miles long. Then I will pick my way back by some single track. ( do this ride several times a year) I start out with a colder plug than I would normally run and probably go a little more to the "chicken side" of jetting. on the way back on the single track i will probably switch to what i usually run. Eg. Setting up a two stroke for a supercross inspired track. Lots of sharp jumps in other words, close to one another. For that kind of riding you need a bike that doesnt bounce the float bowl so empty that you come up with air instead of fuel running up the needle jet. Doing that makes the motor want to die in the worst places That means a higher float level that can end up sending raw gas down the intake more than usual. The pros ran higher float levels to get around that and a hotter plug. 6's were really popular. Be ready to ring the r's up with the clutch, as the pros constantly did though.
For colder weather you get a leaner running engine than the same jetting in warmer weather. I used to see lots of guys put hotter plugs (mostly atv owners) in their rigs and come out to the ice races after taking a parts person's advice on plug selection. I saw lots of them pushing rigs with seized pistons and holes in pistons too.
Too cold is a cheaper fix than too hot.
Heat ranges will not solve a top end rpm shortcoming as far as I have ever seen.
Some things I found: Plugs for weather or jetting (weather and jetting being closely related) are not a good "fix". all that said they can be a bandaid, if you know how to use bandaids. Eg: you are going to ride from 2000 feet to 8000 feet in one ride. Lots of downhill coasting. I carry a hotter plug with me as a replacement if my rig doesnt like the big change in jetting requirements. Just know you can't hold the throttle on for as long as you could with the colder plug without creating a spot that may be hot enough to bring on detonation and preignition.
Eg. I am going to do a flat out run on a dry river bank that is double digit miles long. Then I will pick my way back by some single track. ( do this ride several times a year) I start out with a colder plug than I would normally run and probably go a little more to the "chicken side" of jetting. on the way back on the single track i will probably switch to what i usually run. Eg. Setting up a two stroke for a supercross inspired track. Lots of sharp jumps in other words, close to one another. For that kind of riding you need a bike that doesnt bounce the float bowl so empty that you come up with air instead of fuel running up the needle jet. Doing that makes the motor want to die in the worst places That means a higher float level that can end up sending raw gas down the intake more than usual. The pros ran higher float levels to get around that and a hotter plug. 6's were really popular. Be ready to ring the r's up with the clutch, as the pros constantly did though.
For colder weather you get a leaner running engine than the same jetting in warmer weather. I used to see lots of guys put hotter plugs (mostly atv owners) in their rigs and come out to the ice races after taking a parts person's advice on plug selection. I saw lots of them pushing rigs with seized pistons and holes in pistons too.
Too cold is a cheaper fix than too hot.
Heat ranges will not solve a top end rpm shortcoming as far as I have ever seen.
not really it was more trail and error.. i was pleasantly surprised with the results i got..before this i thought my jetting was all wrong but now i think its pretty good..there's even torque low down in 2nd gear she'll pick up front 0mph..which i think is good for a 125 with a 12 stone man on it.. can any other 125 riders tell me what kinda power/torque there getting out of there bikes..or should she pick up in 3rd and 4th from 0/5 mph. . mine will slug away in 3rd iv i let it..i must post some videos of me riding to show the pick up..
I dont have any 125's that are still 125's. I have some 144 and 139cc ones. It surprises some about how differently they work. I asked about floats, because for a very long time doing that has been one of my first procedures when tuning anything. Over the years I have gotten a whole lot of great deals from people who just figured the bike was too old to ever run right again. (some of those were in the 3-5 year old range.)
I have been so bad about not keeping pics, I do have some of one of my favorite short trackers. It is an xl350 in a champion frame. (street tracker now) I should get some fresh pics of that. i dont know if anyone likes spanish rigs or not, but I have an Ossa and a Montesa vr414 that can look kind of photogenic.