[Gremlyn71]

Hey I just picked up a 2001 cr125 and after looking at gearbox oil found it very low, topped off oil fitted new plug and mixed fresh 32:1 fuel but it looks like gearbox (trans) fluid comimg out exhaust ?

[Back2-2]

Hello, first at 32:1 mix you are going to get quite a bit of oil spuge out the muffler. If it is in fact transmission oil which I doubt, you would have to have crack in the gear case allowing the trans oil to migrate to the crank case. I think you are seeing the heavy oil mixture out the muffler and very possibly jetted to rich. You should be using a quality 2 stroke oil in the 50:1 mixture range. Quality fuel also. Check your plug and see if it is very oily / wet. You need to get the jetting dialed in on the 2 strokes for good performance.
The 2001 is a great bike and year for Honda CR's. I rode a '01 CR 250 for several years in the sand dunes and MX track.

[bosshaug1]

Agree with Neil, definitely learn to check your plug and jet correctly. We ran our CR80 a smidge rich from a perfect setting to keep it running cool and we always had some exhaust sludge out the silencer. Just remember you will have to repack the silencer more often than on a 4-stroke.

[JimDirt]

I agree on the repack , to tell what is going on , you should repack the muffler/silencer , if it was exceptionally rich , the packing will be saturated with the oil and you should notice a continual decrease in oil out the muffler/silencer after a repack ...

Also elevation plays a part in spooge at a specific mixture , in other words , 32:1 at sea level is different than 32:1 at 3,000 ft , it will run richer at the higher elevation with the same fuel mixture because the air is thinner , so you may need to rejet if the bike came from a different elevation than you are currently riding it

For Sea Level you should be at a 380 main jet and a 45 pilot , the AIR screw should be around 2-1/4 out , and the needle 3rd groove from the top , Honda does recommend 32:1 for that bike , Also you could have a leaking Right Crank Seal , that will affect the mixture as well ..

Here is the jetting specs for your bike per elevation changes from the Factory Honda Service Manual:

[Back2-2]

If he continues to run the 32:1 mixture he will continue to get crap dripping out the silencer and heavy coking in the exhaust port. Modern 2 stroke oils are intended to be run 50:1 or even leaner. Remember when Bel-Ray showed up back in the 70's and people tried to run it at 20:1 like the manuals told them to? Gave Bel-Ray a real bad image until the word got out to run it at 50:1.

[JimDirt]

Yea , I know , in the 70's I used to run Power Stroke (Bel-Ray) at 40:1 in my 76 YZ125C at around 1,000ft , as well as in my 79 YZ250 ....... it was Synthetic and it was all I ever ran , I think even Yamaha back then also recommended 20:1 ..... just stating what the Manual says as far as "stock" settings , my buddy I ride with rides 2 smokes a lot , he is always spooging , and I think he runs 32:1 as well (Honda oil) ,I keep telling him to run 40:1 but he says its too lean a mixture .....

The jetting was more of the focus of my post , if he is jetted rich , then that will exacerbate the issue .... , he needs to make sure his jetting is correct for the elevation/temp first , otherwise , he is not going to help the situation .... and none of his settings , like air screw , are going to be where they need to be if he is fighting a jetting issue , so it is just going to make dialing it in that much harder , he did not mention if the person he bought it from was at the same location/elevation , nor did he mention his elevation or jetting , so I always assume it is different , and to eliminate that from the equation .... , then he has a place to work from .... get the jetting correct , so the bike runs like its supposed to , then dial in the mixture ... ... but yea I agree he needs to go to at least 40:1 to stop the spooging

That is why I like 4 strokes now .... way less hassle , get jetting right , then adjust the fuel screw for about 2,500 ft difference in changes and no spooge to clean after every ride ......

[Gremlyn71]

Hey guys thanks for the reply, bike came from same elevation and did have tons of crap in the exhaust this is the first time I have started the bike so drained fuel and mixed fresh fuel but will try dropping the mix down to around 40:1 after I have pulled carbie to see what jets are in it and will pull exhaust and try cleaning it out and see what difference that makes. Thanks again for the pointers been a few years since owning a 2 smoke its given me a bit more hope thinking it is most likely too rich

[Aussiecrf230]

Talk about a nostalgia post from my younger day.

Best advice I can give is choose a brand of oil and a mixture ratio and stick with it. Then adjust jetting to suit.
My sons 200exc flowed black crap out of the exhaust. Stayed with the ratio in the owners manual but changed jetting including the needle. Stopped the black river and woke the bike up.
It was unburnt fuel it was so rich on factory jetting not the oil.
Remember guys the PE250 made best horsepower on a 16:1 mix.

[Back2-2]

I agree with you Jim. The jetting being correct is the number one on the list to get corrected. But at 32:1 is to rich of oil for modern bikes and modern oils. But the jetting also has to be done at whatever he decides to use as the ratio and stick to it.
More oil in the fuel is less fuel. You can actually adjust jetting be changing the oil ratio - to a point. But coking is an issue for the exhaust valves and the exhaust port that needs to be concerning. Otherwise you will be taking it apart and cleaning the build up way more often than should be required.

I love 2 strokes and have both because both 4 and 2 strokes have their place.

[Gremlyn71]

Thanks again guys for getting back to me, So I got the carbie off tonight and have found it to have 380 main 50 pilot needle clip in the 4th position and screw 2 turns out. Now I didn't mention it has a pro circuit pipe and after looking on their site it says for 2001 cr125 use a 370 main 37.5 pilot needle is a 6BEG20-69 set on 2nd position and 1.5 turns out as a starting point.
What is the difference between standard 6BEG20-68 needle and the 6BEG20-69 ? Taper ? and length ? Cheers guys Steve.

[Back2-2]

The taper will have a different profile between the two different needles. Probably thru the middle section of the taper. If you want to try the suggested jetting without changing the needle you can do that and use the clip position to make mid range fueling adjustments to get you in the ball park. I do not if the 125's in 2001 had the erratic carb the 250's did but the 250's were a bear to get dialed in perfectly. The needle change is probably a good suggestion.

[Gremlyn71]

So I have changed main jet to 370 pilot to a 45 and move clip on needle to 3rd position set the screw two turns out as a base to start with but I broke the cable holder that screws into top of carb slide so have ordered a new one and waiting for it to arrive.
So I thought while I am waiting may as well have a look at right side crank seal and found it damaged and only just sitting in the case so its looking like it was the crank seal letting trans fluid into crank case, so I have changed the seal and started putting kick start spindle and clutch etc back in when I have found a dowel pin 4mm x 11.75mm just sitting in the bottom of the exhaust power port casting area and for the life of me cant work out where it has come from ?

[Gremlyn71]

Here is a pic of where I found the dowel pin

[Back2-2]

Crank shaft seal. Well Jim won that one. I have not seen a crank seal leak in many, many years. Good catch.

That dowel looks very familiar but I cannot place it? I think I remember it is part of the power valve assy. A limit pin or something like that- I just can't remember. It's just been too many years since I had my 2001 CR250. I suggest going to the parts diagrams on the site here and look at the parts layout and see where it goes.
Maybe Jim will know.

[Gremlyn71]

The limit pin is still in place you can see it in the pic top left of the power valve assembly, but just above where I found the pin there is two holes a small one on the bottom could be a drain hole ? and slightly larger hole above the small one could this be a dowel to line up cases ? only place I could see it coming from. Thanks Steve.