1984 Rm 250 - Motorcycle-Journal Forums

robcromwell · 04-23-2006, 11:39 PM

I'm having problems with my bike. When accelerating, the bike spits and backfires and reaches high speeds very slowly. Once the RPM's get up, the bike has lots of power and doesn't sputter at all. The airflow screw is set to 1 1/2 turns out. The plug is black with carbon, and when I bought the bike, the baffle was plugged solid with carbon and what appeared to be oil. Also, when it is idling, there is fuel coming out of the carbeurator from the openings in both sides. Any suggestions?

Dave2122 · 04-24-2006, 10:46 PM

You need to adjust the float height inside the carb float bowl. Find out the propper specs in your service manual or from a dealer. You may have to change to a brand new plug once the float height is corrected. The old plug may be fouled and no longer any good.

robcromwell · 04-25-2006, 10:23 PM

I adjusted the float to the factory specs of 10,9-11.9mm, and changed the plug, and the problem is still there. Once I get past the spitting and sputtering and the bike gets up to high RPM's, it's fine. It starts ok, and idles ok too, and after adjusting the floats the carb stopped leaking. Could it possibly be an electrical problem? To me, it sounds like fuel, but I think I've tried everything.

bigE · 04-25-2006, 11:12 PM

I am having similar problems with my 86 rm250. It has no bottom end power and a very small top end power band. I adjusted the timing and it is much better than what it was, but it still runs pretty bad..... Mine wont start when its cold without a shot of carb cleaner and it wont idle either though.....

Dave2122 · 04-26-2006, 08:29 PM

If that is the case then you need to clean your carbs by removing the Brass Needle valve and mainjet and air screw etc........Also check for a minor air leak around the intake manifold and the base gasket.

robcromwell · 04-27-2006, 10:00 PM

Found it!!! There was a loose ground on the coil. Also, the circlip for the jet needle fell off, and the needle was just bouncing around with no way of regulating the amount of fuel to the engine. Thanks for your suggestions

stingray_69 · 05-15-2006, 01:32 PM

I have an 84 rm250 and I don't think I have an air screw. There is nothing where the Clymer manual shows it to be. I dont know if its because it looks different than on the other bikes I've owned or because the carb I have is not the stock carb. Can you tell me where and what yours looks like robcromwell

robcromwell · 05-15-2006, 10:57 PM

The air screw is located near the airbox intake. On the link that follows, it's #18 on the chart. The manufacturer suggests it be turned 1 and a half turns out.

http://alpha-sports.com/smoto/1984%20RM250/02.htm

04-23-2006, 11:39 PM	#1 (permalink)
robcromwell Newbie Joined: Apr 2006 Bike: 1984 RM250 Location: Alberta Canada Posts: 11	1984 Rm 250 I'm having problems with my bike. When accelerating, the bike spits and backfires and reaches high speeds very slowly. Once the RPM's get up, the bike has lots of power and doesn't sputter at all. The airflow screw is set to 1 1/2 turns out. The plug is black with carbon, and when I bought the bike, the baffle was plugged solid with carbon and what appeared to be oil. Also, when it is idling, there is fuel coming out of the carbeurator from the openings in both sides. Any suggestions?

04-24-2006, 10:46 PM	#2 (permalink)
Dave2122 Sprocket Pilot Joined: Sep 2004 Bike: Which one of the 9? Location: USA Posts: 887	You need to adjust the float height inside the carb float bowl. Find out the propper specs in your service manual or from a dealer. You may have to change to a brand new plug once the float height is corrected. The old plug may be fouled and no longer any good. Last edited by Dave2122; 04-24-2006 at 10:51 PM.

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04-25-2006, 10:23 PM	#3 (permalink)
robcromwell Newbie Joined: Apr 2006 Bike: 1984 RM250 Location: Alberta Canada Posts: 11	I adjusted the float to the factory specs of 10,9-11.9mm, and changed the plug, and the problem is still there. Once I get past the spitting and sputtering and the bike gets up to high RPM's, it's fine. It starts ok, and idles ok too, and after adjusting the floats the carb stopped leaking. Could it possibly be an electrical problem? To me, it sounds like fuel, but I think I've tried everything.

04-25-2006, 11:12 PM	#4 (permalink)
bigE Kickstand Operator Joined: Apr 2005 Bike: 2000 SV650 & 2000 Marauder Location: DFW, Texas Posts: 278	I am having similar problems with my 86 rm250. It has no bottom end power and a very small top end power band. I adjusted the timing and it is much better than what it was, but it still runs pretty bad..... Mine wont start when its cold without a shot of carb cleaner and it wont idle either though.....

04-26-2006, 08:29 PM	#5 (permalink)
Dave2122 Sprocket Pilot Joined: Sep 2004 Bike: Which one of the 9? Location: USA Posts: 887	If that is the case then you need to clean your carbs by removing the Brass Needle valve and mainjet and air screw etc........Also check for a minor air leak around the intake manifold and the base gasket.

04-27-2006, 10:00 PM	#6 (permalink)
robcromwell Newbie Joined: Apr 2006 Bike: 1984 RM250 Location: Alberta Canada Posts: 11	Found it!!! There was a loose ground on the coil. Also, the circlip for the jet needle fell off, and the needle was just bouncing around with no way of regulating the amount of fuel to the engine. Thanks for your suggestions

05-15-2006, 01:32 PM	#7 (permalink)
stingray_69 Newbie Joined: May 2005 Posts: 22	I have an 84 rm250 and I don't think I have an air screw. There is nothing where the Clymer manual shows it to be. I dont know if its because it looks different than on the other bikes I've owned or because the carb I have is not the stock carb. Can you tell me where and what yours looks like robcromwell

05-15-2006, 10:57 PM	#8 (permalink)
robcromwell Newbie Joined: Apr 2006 Bike: 1984 RM250 Location: Alberta Canada Posts: 11	The air screw is located near the airbox intake. On the link that follows, it's #18 on the chart. The manufacturer suggests it be turned 1 and a half turns out. http://alpha-sports.com/smoto/1984%20RM250/02.htm

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