bogging down

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trix
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bogging down

#1 Post by trix » Fri May 05, 2017 5:03 pm

Hi
This relates to my RS250, but thought I'd tap into the general 2-stroke knowledge on here! My RS250 started to run on one cylinder.

New plugs; no real difference.

Stripped and cleaned the carb on the offending cylinder. Set the float height correctly. Helped a lot, both cylinders running ok but running poorly at very low rpm/idle.

Got a new battery and verified that the charging system is working ok, but no improvement in low rpm /idle.

When warmed up, it wants to bog down unless I open the throttle very slowly. If I snap the throttle open it dies. (idle set to 1500 rpm)

Any ideas?

Also in a separate problem, I just noticed that when the brake light is illuminated, the indicator tell tale on the dash lights very dimly. Is that a bad earth somewhere?

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Rick Lance
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Re: bogging down

#2 Post by Rick Lance » Fri May 05, 2017 6:30 pm

Have you been riding your RD500 a lot lately?

Is it possible that after doing so, your RS feels like it's only running on one cylinder?

(well, what kind of comments did you expect to get from a bunch of 500 owners?) :razz:
If I disagree with everyone, that doesn't make me right. If I take the side of only one, it doesn't end the fight. If my position's strong enough from exposure to the light, you may see things my way when we share the same highway.

vdrive
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Re: bogging down

#3 Post by vdrive » Fri May 05, 2017 11:38 pm

my rg400 was acting up , # 3 piston was starting to seize , glad I took it apart as cylinder was still ok after a hone . only 14000 miles

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two-stroke-brit
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Re: bogging down

#4 Post by two-stroke-brit » Sun May 07, 2017 3:42 pm

vdrive wrote:my rg400 was acting up , # 3 piston was starting to seize , glad I took it apart as cylinder was still ok after a hone . only 14000 miles
did you find out why?
She might not be pretty but always a fun ride !!

silverstrom
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Re: bogging down

#5 Post by silverstrom » Sun May 07, 2017 3:46 pm

It still sounds like pilot jets, but electrical issues will often come across as fuel issues. Did you meter your stator? Just wondering about the low speed coils.

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Smoker
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Re: bogging down

#6 Post by Smoker » Mon May 08, 2017 1:10 am

More help here:

http://www.apriliaforum.com/forums/forum.php" onclick="window.open(this.href);return false;

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Re: bogging down

#7 Post by MK » Mon May 08, 2017 2:33 pm

If you quickly open the throttle and it dies off you usually have to few fuel supply.
(Clogged jets)

The only other reason is the electrical issue you mentioned. The RS has a DC CDI which means it needs 12V to run. Have you checked with a multimeter at the battery that the voltage doesn't drop below some 8 or 9 V?
I have similar issues in my total loss race bike when the bat runs low.
Bye
Martin

vdrive
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Re: bogging down

#8 Post by vdrive » Tue May 09, 2017 1:51 am

two-stroke-brit wrote:
vdrive wrote:my rg400 was acting up , # 3 piston was starting to seize , glad I took it apart as cylinder was still ok after a hone . only 14000 miles
did you find out why?
Hi two-stroke-brit , no never figured it out , oil pump good , oil lines good , carbs good , I had bought it with 8900 on the clock , new gas filter ( both sides of stock carbs ) . # 3 piston ( put in new piston & rings ) honed cylinder , put on new head gasket & lower gasket , runs great with Sugaya expansion chambers , Rick Lance air filter kit .

trix
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Re: bogging down

#9 Post by trix » Wed May 10, 2017 4:24 am

MK wrote:If you quickly open the throttle and it dies off you usually have to few fuel supply.
(Clogged jets)

The only other reason is the electrical issue you mentioned. The RS has a DC CDI which means it needs 12V to run. Have you checked with a multimeter at the battery that the voltage doesn't drop below some 8 or 9 V?
I have similar issues in my total loss race bike when the bat runs low.
Checked this and voltage is always over 12v (about 14.3v). I'll clean the carbs again!

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Jeff B
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Re: bogging down

#10 Post by Jeff B » Wed May 10, 2017 2:19 pm

It wouldn't hurt to synchronize them as well. That tends to cause a fast idle though.

trix
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Re: bogging down

#11 Post by trix » Sat May 20, 2017 6:45 am

silverstrom wrote:It still sounds like pilot jets, but electrical issues will often come across as fuel issues. Did you meter your stator? Just wondering about the low speed coils.
Hey silverstrom, you were right. Cleaned the carbs again in the ultrasonic and went up one size on the pilot jets.
problem sorted and driving better from low throttle.

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