Honda CR 125 ?

[Uptown_Blaster]

My cousin has a 1998 honda cr 125. I figured someone on here would be able to help. He just had a rebuild done and it rode good for about a week but now it keeps fouling out the plugs. We put a new plug in, it kicks right on. Then if he cuts it off, it does not want to start. Then we replace the plug and kicks right on again. The fouled plugs come out pretty wet.

What the hell could be causing this?? Thanks

 

[bobdryerr]

running to rich......

 

[stephen12091985]

the jetting is way rich it sounds like

 

[Uptown_Blaster]

OK, Ima little new to jetting. Does he need to purchase new jets that run leaner or is this something that can be adjusted?

 

[bobdryerr]

depends some jet kits r adjustable an some u have to buy new jets

 

[blasters/banshees]

try running a hotter spark plug and rev the piss outta it and you wont have this problem...........if you going really slow in tight woods with the recommended plug(for mx) the bike is going to foul plugs all the time..........run a hotter plug maybe 2 sizes down and keep the bike in powerband all the time and (clear it out every now and then pull in the clutch and rev it hard) if your in tight woods

 

[jostith]

The last one sounds about right. Or you could rejet for what you ride but then on open flats it would run lean and tear up. Did he normally ride in the same area or has it changed? Also did he replace the spark plug with the rebuild and change it?

 

[Uptown_Blaster]

We are going to try this with the hotter plug.

He normally rides on straight flats. Only been on a tight trail a few times, but not recently. The plug was changed immediately after the rebuild. I think if the hotter plug does not work then I am going to try to check the jets.

 

[blasters/banshees]

my cr85 I just got the topend rebuild and its fouled about 5 of the plugs until I went to the hotter plug.......just make sure you stay on the pipe and clear it up all the time

 

[Uptown_Blaster]

my cr85 I just got the topend rebuild and its fouled about 5 of the plugs until I went to the hotter plug.......just make sure you stay on the pipe and clear it up all the time

What brand of plug did you use and what did you gap it at? I havent been gapping the plugs at all when we get them. Sorry but what exactly does stay on the pipe mean?

Gotta learn somewhere . . .

 

[Whitty21]

to find a hotter plug, just take your size for example the blaster is a br8es, a hotter plug would be a br7es and on and on, but check the plug a lot, if the end starts going white at the end then you are running too hot then got to a cooler plug

 

[Brute71]

to find a hotter plug, just take your size for example the blaster is a br8es, a hotter plug would be a br7es and on and on, but check the plug a lot, if the end starts going white at the end then you are running too hot then got to a cooler plug

wrong, white means lean. The plug will have a yellow glazing on it from a sudden increase in combustion chamber temps (too hot of a plug for riding conditions).

 

[BustedassYZ]

Deff try a hotter plug, then If that doesn't do it I'd think about replacing the clutch side crank seal before I started swapping brass.

 

[mystahagy]

Correct your jetting before straying from the recommended plug. Also avoid starting it unless you are actually gonna take it for a ride. Running for only a few secs doesn't let the plug come up to temperature and they'll come out wet.

 

[Jrodfolyfe]

it sounds like your mix is tooo rich lean it up a lil bit

 

[blasters/banshees]

What brand of plug did you use and what did you gap it at? I havent been gapping the plugs at all when we get them. Sorry but what exactly does stay on the pipe mean?

Gotta learn somewhere . . .

no I didnt gap the plugs I run ngk plugs only..........stay on the pipe means keep it in powerband at all times

 

[blaster99]

98 were notorious for plug fouling

 

[mystahagy]

it sounds like your mix is tooo rich lean it up a lil bit

Just in case there's any confusion, you DO NOT correct jetting problems by adjusting premix ratio or running hotter/colder plugs. There is no shortcut that doesn't bring problems of its own. Do it right.

Also, what many do not realize is that when you put less oil in your premix you actually run richer.

Nothing personal or directed towards you bro, there's just way too much bad advice that gets repeated over and over on this forum. It's been bugging me lately.

 

[blasters/banshees]

Just in case there's any confusion, you DO NOT correct jetting problems by adjusting premix ratio or running hotter/colder plugs. There is no shortcut that doesn't bring problems of its own. Do it right.

Also, what many do not realize is that when you put less oil in your premix you actually run richer.

Nothing personal or directed towards you bro, there's just way too much bad advice that gets repeated over and over on this forum. It's been bugging me lately.

hotter and colder plugs can make a big diffrence and thats all it was in my bike

 

[mystahagy]

hotter and colder plugs can make a big diffrence and thats all it was in my bike

Hotter plugs can self clean quicker in a rich environment, but that doesn't mean your jetting is correct and it's not the ideal way to compensate. This hotter plug increases your risk of detonation and preignition. In some applications it's ok, but it's not a catch-all solution, ESPECIALLY if this bike was running fine for a period of time before it started eating plugs.

But oh well, put in a hotter plug. That seems to be the popular advice right now.