Strange engine stumble.. just started today.

kens97sto171 · 05-21-2008, 05:44 PM

Hey all.. I have a 06 Roketa DB07, have 2400 miles on it now. I have NEVER had any trouble with the carb, or any engine issues for that matter. The bike has a 46t sproket, and a UNI filter. There is no fuel filter on it...other than the screen in the petcock.

The bike has been sitting for 3 weeks (have done that many times without trouble) only difference this time is the bike has been outside, and rained on several times... before it was kept in a garage. fuel level was about 1/2 tank.

Bike started right up and idled fine... I let it warm up while I got my gear on.. Hopped on it, took off without any issue.. got about 1/8 mile and it started stumbling very badly... bike would not go except at idle... it idled fine... but when you crack the throttle it would not rev... got it back to the parking spot, and mesed with trying to rev it, put the choke on a little and it could rev up then.. did some WOT reving, and back to idle... seemed to clear it up... went back out to ride, and it was fine again for a short distance... then acted up again.. then cleared up again.

I got it to a gas station and filled up with 93... then to auto parts place and put some HEET stuff in it.. to absorb water.... figured it was worth a try.

Well ... it seemed to help.. but the weird thing is that as long as you are riding the bike.. it runs fine now.. but if you sit at a lite for a while it then will act up a little.. then clears again after a few revs with the choke on, and goes away completely after your moving.

Any thoughts????? I am thinking that some crud is floating around in the carb?? at idle it settles at the bottom and clogs it up.. the vibration from riding must stir it up and unclog it.

Thanks for the help.

Ken

IronFist · 05-21-2008, 05:58 PM

I am thinking that some crud is floating around in the carb

kens97sto171 · 05-21-2008, 06:11 PM

Quote:

Originally Posted by IronFist

I am thinking that some crud is floating around in the carb

FUNNY MAN!!! I guess I did sorta answer my own question...
But really if anything else comes to mind I would appreciate the suggestions.. Dont really have the time to work on it now... if I have to take the carb apart.

Thanks

Ken

VinceDrake · 05-21-2008, 06:19 PM

Just guessing, but by what youy describe, it sounds like some crapola got into the carb, and is resticting the main jet. Putting the choke on and giving her the WFO treatment, would cause extreme high vac, and cause it to suck crap restrictions through-- We used to do the same type of thing to clean out old Toyota Carbs. (No-one wanted to take them apart for some reason...)

Maybe a carby strip and clean is in order....

--Vince

theENIGMATIC · 05-21-2008, 07:13 PM

You ever seen that movie Christine....I think your bikes alive man and it might be pissed off? :twisted:

kens97sto171 · 05-21-2008, 07:41 PM

Quote:

Originally Posted by theENIGMATIC

You ever seen that movie Christine....I think your bikes alive man and it might be pissed off? :twisted:

YEAH!!! Mabye it got pissed off cause I left it out in the rain for the first time in 2 years... It had a nice warm place to sleep before that...

BTW thats a great movie... Loved that 57 Fury...

ambassador · 05-21-2008, 11:16 PM

It got rained on, if that's the only variable then that's where I'd start to look, most of these bikes dont like water...

katoranger · 05-21-2008, 11:18 PM

Check the connections on the CDI/coil for corrosion. Allen

fatboy250 · 05-22-2008, 08:49 AM

CHECK the rubber intake manifold that mounts to the engine from the carb....you may have a crack or split. CHINA RUBBER is terrible. Silicon will fix it if it is the problem...until you can find a permanent solution.

kens97sto171 · 05-25-2008, 09:21 PM

Went out today.. bike acted as before but not as long till it cleared up.. After my test ride.. I thought about the petcock.. and so I tried messing with it.. When you turn off the valve.. nothing happens.. bike keeps running.. turned it back on, bike acted weird again for a min... Then noticed the fuel like is cracked looking around the petcock.. It is the original fuel line and petcock.. I am thinking the rubber is coming apart inside and clogged the carb up or the fuel needle... Bike still running OK though after you get it out on the road... only messes up when you let it sit and idle for a while.... WEIRD... gonna just have to take it apart to see.

Ken

warrior91 · 05-25-2008, 11:54 PM

You are sucking air in with your fuel and probably not getting enough fuel to run right when the carb is demanding it acording to throttle position.
You also have the possibillity of leaning it out if you force it.

My 2 cents for what that is worth with inflation and all. :roll:

05-21-2008, 05:44 PM	#1
kens97sto171 Join Date: Mar 2007 Posts: 193	Strange engine stumble.. just started today. Hey all.. I have a 06 Roketa DB07, have 2400 miles on it now. I have NEVER had any trouble with the carb, or any engine issues for that matter. The bike has a 46t sproket, and a UNI filter. There is no fuel filter on it...other than the screen in the petcock. The bike has been sitting for 3 weeks (have done that many times without trouble) only difference this time is the bike has been outside, and rained on several times... before it was kept in a garage. fuel level was about 1/2 tank. Bike started right up and idled fine... I let it warm up while I got my gear on.. Hopped on it, took off without any issue.. got about 1/8 mile and it started stumbling very badly... bike would not go except at idle... it idled fine... but when you crack the throttle it would not rev... got it back to the parking spot, and mesed with trying to rev it, put the choke on a little and it could rev up then.. did some WOT reving, and back to idle... seemed to clear it up... went back out to ride, and it was fine again for a short distance... then acted up again.. then cleared up again. I got it to a gas station and filled up with 93... then to auto parts place and put some HEET stuff in it.. to absorb water.... figured it was worth a try. Well ... it seemed to help.. but the weird thing is that as long as you are riding the bike.. it runs fine now.. but if you sit at a lite for a while it then will act up a little.. then clears again after a few revs with the choke on, and goes away completely after your moving. Any thoughts????? I am thinking that some crud is floating around in the carb?? at idle it settles at the bottom and clogs it up.. the vibration from riding must stir it up and unclog it. Thanks for the help. Ken
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05-21-2008, 05:58 PM	#2
IronFist Join Date: Apr 2007 Location: Toronto Ontario Canada Posts: 2,585	I am thinking that some crud is floating around in the carb __________________ IronFist ___________________________________ The "chain" of command is used for beating spammers. ___________________________________
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05-21-2008, 06:19 PM	#4
VinceDrake Join Date: Nov 2007 Location: Southern Saskatchewan Posts: 491	Just guessing, but by what youy describe, it sounds like some crapola got into the carb, and is resticting the main jet. Putting the choke on and giving her the WFO treatment, would cause extreme high vac, and cause it to suck crap restrictions through-- We used to do the same type of thing to clean out old Toyota Carbs. (No-one wanted to take them apart for some reason...) Maybe a carby strip and clean is in order.... --Vince __________________ "Sometimes it is better to say nothing, and let people think you're an idiot, than to open your mouth and prove it."
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05-21-2008, 11:16 PM	#7
ambassador Join Date: Jan 2007 Location: Bradenton, Florida Posts: 1,200	It got rained on, if that's the only variable then that's where I'd start to look, most of these bikes dont like water... __________________ 06 Lifan 200 GY-5
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05-21-2008, 11:18 PM	#8
katoranger Join Date: May 2007 Location: Altamont, Kansas Posts: 15,103	Check the connections on the CDI/coil for corrosion. Allen __________________ You meet the nicest people on a Honda Clone.
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05-21-2008, 07:13 PM	#5
theENIGMATIC Join Date: Feb 2008 Posts: 392	You ever seen that movie Christine....I think your bikes alive man and it might be pissed off? :twisted:
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05-22-2008, 08:49 AM	#9
fatboy250 Join Date: Sep 2006 Location: COLUMBIA, SC Posts: 973	CHECK the rubber intake manifold that mounts to the engine from the carb....you may have a crack or split. CHINA RUBBER is terrible. Silicon will fix it if it is the problem...until you can find a permanent solution. __________________ 2008 Jonway MC-70-150 2007 Roketa DB-07B (RSM-200E) 2006 Roketa DB-07A (RSX-200E) 1995 Kawasaki Concours (ZG1000)
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05-25-2008, 09:21 PM	#10
kens97sto171 Join Date: Mar 2007 Posts: 193	Update on weird problem Went out today.. bike acted as before but not as long till it cleared up.. After my test ride.. I thought about the petcock.. and so I tried messing with it.. When you turn off the valve.. nothing happens.. bike keeps running.. turned it back on, bike acted weird again for a min... Then noticed the fuel like is cracked looking around the petcock.. It is the original fuel line and petcock.. I am thinking the rubber is coming apart inside and clogged the carb up or the fuel needle... Bike still running OK though after you get it out on the road... only messes up when you let it sit and idle for a while.... WEIRD... gonna just have to take it apart to see. Ken
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05-25-2008, 11:54 PM	#11
warrior91 Join Date: Nov 2007 Location: N.E. Saskatchewan, Canada Posts: 679	You are sucking air in with your fuel and probably not getting enough fuel to run right when the carb is demanding it acording to throttle position. You also have the possibillity of leaning it out if you force it. My 2 cents for what that is worth with inflation and all. :roll: __________________ '91 Yamaha Warrior- stage 2 '83 Honda ATC 70 '08 Yongjiang 125cc mx (Loncin) '08 Yongjiang 150cc atv (Jinlong)
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