91' Rm 125

[DirtDigger1]

Im running a 91' RM 125 with a fuel capacity of 2 Gall. 8 Ounces. My question is, using the mobile one MX2T oil, how much of the oil do I put in the bike with standard gas for it to run properly without fouling plugs? I cant even kickstart my bike, i have to run it down a hill to get it started. Experimenting is costing me alot of time and trouble, above all money. So maybe someone here could help me on this issue. Thanks alot in advance, any help would be greatly apreaciated,

 

[Hucker]

Clymer says run 32:1. My 90 RM250 is rich on the bottom end so i leaned out the pilot and that helped a bit. I run 40:1, which is 3.2 ounces for every gallon of gas..

32:1 is the easiest to mix however, at 4 ounces of premix for 1 gallon of gas. Do some simple math and you'll have it figured out. Also what heat range are you using for your plug? 8? 9? You might want to either lean the jetting out, or try a 1 range lower on the plug...

 

[DirtDigger1]

k, i guess that kinda makes sense. I always thought dif brands of oil make a big difference. Im running 4 ounces of mobile 1 with my 2 gal 8 ouces. To lean? Well plugs dont have oil on them...... so maybe thats true. But how does that ruin the plug?

 

[DirtDigger1]

oh by the way, im not sure what you mean by heat range, im 16, lol gotta put it in simple language...... i use champion, instead of NGK, (only thing auto zone carried, and I was desperate :)) so maybe that will help.

 

[David Trustrum]

Note; if it is too rich using less oil will make it richer & confound fouling problems. Just trust us on this one. Remember it is possible to be too rich on some jets & too lean on others.

Excuse the cut & paste I save old answers

Do the simple stuff first. Sparkplug, Sparkplug cap, clean or replace airfilter (replace by now) Check that the coil is grounded properly. (clean plug contacts, check with meter etc).

Clean carb out properly esp pilot jet (never poke with wire though).

Then start reaching for the jets.

New bikes are usually set up too rich as it is the safe option. If you are using a decent oil at the ratio recommended on the bottle then it will not be the problem, ever.

Once a plug fouls it may not recover properly. Out in the open it may spark well but in a combustion chamber may just foul up again. I really would look at the HT lead & cap as well as they might have been the initial reason for the plug fouling. Use the recommended heat range.

Buy a correct heat range sparkplug first off!

Start playing around with the jetting particularly at low throttle positions (Pilot etc).

Further your coil or stator coil may be weak & once heated up is a bit pathetic so fouls a plug.

 

[Chili]

The heat range is referenced in the number on the plug i.e. BR9 EGV with the lower the number being a hotter plug. Get the recommneded plug for your bike for a start and save the champion plug for a lawnmower.

 

[los36]

Alright DD1,
Here's what I think you are after.
By mixing 4oz per tank, you are running somewhere near 80:1 ratio. That's way too lean of an oil mixture. 4oz per gallon is what you need to run. You may have done some serious damage to your piston and cylinder because of this.
Get the correct spark plug. Find an NGK BR8ES.
Don't worry about your adjusting the jetting yet. For now, you need to get to a baseline.
Do you have the manual? If so, make sure the stock jets are in the carb.
If starting is still hard, check your reeds for chipping or cracking. If they're fine, then check the piston and cylinder for wear.
Good luck!

 

[Stew312]

Try lying the bike on its left side for approx. 30 seconds, then pick her up and give her a kick with the throttle open. Try this and let me know how it works out. I've been messing with my 88 RM250 for months now trying to get it to start easier, but she won't go unless you lie her on the left side. Good luck to ya.

 

[SuzookKING]

not being able to kick start it and only being able to roll-start (push or pull) sounds like you might have lost some compression due to the lack of lubrication (top end damage *piston,ring,cylinder) :eek: .
run a compression check on it if possible :ugg:


depending on how you ride 32:1 to 40:1 should be fine on a 250. :thumb:
get ngk plug even if you have to order one. :thumb: