Tuning with bolt on mods...2005 CR 125

[trickin30]

Hey all....

I recently made a few mods on my 05 CR 125 and am having a few issues. I installed the Power Now, Power Now Plus, FMF Fatty pipe with shorty silencer, and the V-force 3 reeds. My bike runs but it is fouling plugs rather quickly. Stock main jet is a 430 and stock pilot a 55. I have already put a 400 main, 45 pilot, and raised the clip one notch on the needle and am still having problems fouling plugs. It will start and idle but when I start to give it the gas it loads up and fouls the plug. How much of a difference do these mods make on jetting? Will it be ok to go leaner on the main? Please help!! It already cost me a race and a small fortune in spark plugs. I installed a new Wiseco top end 2 weeks ago before the mods and it ran great but now it just plain sucks.

Rick

 

[MXP1MP]

My friend has an '06 model they are the same bikes It's mostly stock right now except the fmf fatty and shorty silencer. We've been playing around with jetting but so far just tried a #45 pilot the stock needle in stock pos and in the 2nd clip. Also went to the next size leaner needle in the middle clip I think the bike was running best on this needle. He recently tried going one richer over stock and I think the bike is running richer now and went one richer on the main just cause it was suggested in mxa :bang: I need to kick his ass to go back to the one leaner needle like before going richer was definetly the wrong direction.

No experience with the V3 on this bike and have never messed around with those power now things I thought they only worked on 4 strokes anyways I'd take'em off personally they sound like they are the problem to me cause the bike ran okay on the stock jetting for us it didn't foul out but it was still rich.

The stock needle is something #68 leaner is #69 and richer is #67 the 67 is the last one we tried with the richer 440 main. It ran best with the #69 needle #45 pilot stock main. Plus we mix it at 50:1 with 927.

 

[motoguru]

Hey all....

I recently made a few mods on my 05 CR 125 and am having a few issues. I installed the Power Now, Power Now Plus, FMF Fatty pipe with shorty silencer, and the V-force 3 reeds. My bike runs but it is fouling plugs rather quickly. Stock main jet is a 430 and stock pilot a 55. I have already put a 400 main, 45 pilot, and raised the clip one notch on the needle and am still having problems fouling plugs. It will start and idle but when I start to give it the gas it loads up and fouls the plug. How much of a difference do these mods make on jetting? Will it be ok to go leaner on the main? Please help!! It already cost me a race and a small fortune in spark plugs. I installed a new Wiseco top end 2 weeks ago before the mods and it ran great but now it just plain sucks.

Rick

check your plug after you get it to temp. if its still black & wet go leaner. v-force reeds will make your bike run richer. if jetting doesn't help check your timing and make sure there is no exhaust restrictions (stuck power valves) try a hotter plug

 

[hammy56]

I had to lean mine quite a bit to stop fouling plugs....2 sizes leaner on the pilot and one on the main....it runs much better for sure, and no more fouling plugs :cool: Im wanting to try the 1 size leaner needle but havent ordered it yet....Im at sea level (FL) and have a PC pipe and shorty silencer. Ive never had a bike that ran well on stock jetting, theyve all needed to go leaner.

 

[briguy125]

I run a BR8ES plug in my cr125 and it runs much better

 

[MudlakeRacing]

Float is set to high

Your float is set to high and gas is slashing up and in and no jetting will fix it. Have some one reset your float hieght and then rejett and you will be happy.

 

[Patman]

The thread is from 2005.

 

[hot125mod]

damn you run 927 at 50:1 that seems awful lean to me

 

[inotocracy]

2006, actually. Yikes.