Trouble Reving

mcintyre_aerospace · 10-14-2007, 09:01 PM

Well I cant really think of a way to sum up my bikes problems. Yesterday I tried to start it, and got nothing at all ,almost ran the battery down trying everything I could. Today I removed the carb and cleaned all the jets and holes and anything I could think of, I also checked the float hight. I reassembled it and put it back on the bike a little while ago. Now the bike sometimes has real trouble starting, but on occasions it'll start right away. The biggest problem I have is that it will not rev past id say about 2000rpm when the choke is off. Somehow it runs with the choke on, i don't really understand why. Third when try and test ride it I hear a lot of popping sound from the muffler. Does anyone out there get any of these kind of problems?? Please help.

Easy Rider · 10-14-2007, 10:42 PM

Quote:

Originally Posted by mcintyre_aerospace

Does anyone out there get any of these kind of problems?? Please help.

It would help with the continuity of the suggestions if you would NOT start a new message thread every time the symptoms change a little bit. :cuss:

It would be better if you continue with the thread you already started !! :oops:

IIRC, you've had two tries at cleaning the carb, right? It still sounds like a carb problem.
In an earlier message, you said something about buying a new carb. I suggest you DO THAT.........or take it to a shop for proper carb repair.
Somehow I feel that you taking a THIRD try at it wouldn't accomplish much.

Jaime · 10-15-2007, 09:25 AM

Lean mixture sympthoms. If the carburetor is in good condition, check for any false air entrance to the cylinder or before the carb.
When I modified the air filter, the bike wasn't reving over 1/3 throttle and I had to richen the mixture.

mcintyre_aerospace · 10-15-2007, 04:37 PM

Well excuse me, I thought it was about the choke, hmmm. This carburetor isnt as complicated than the ones Ive had on my 302 Tiger, and ive repaired them many times. I guess ill remove the exhaust, check for blocks, and try the needle shim mod. If anyone actually knows where you can buy a mikuni BSR32SS carb, itd help. I cant really spend 350 dollars for one, I only spent around 500 for the entire bike. I guess ill try dealerships, but they allways want a lot. There may be other carbs I can use too. thanks Jaime.

Jaime · 10-15-2007, 05:24 PM

You should do a major overhaul of the carb if you haven't completed it already: Check the throttle valve membrane, possibly blocked air jets or fuel valve filter -outside of the carb-, or maybe broken old rubber joints. Also, verify that the intake pike isn't slashed and that there are no air entrances between the carb and the air filter (properly connected oil sump gas tubes). Run the motorcycle with the fuel valve on PRI (or constant fuel supply), to check if the vacuum membrane is damaged and the fuel isn't filling the float chamber. Once corrected the problem, you can "shim" the jet needle, not before.

Remember that when you use the choke, you're closing some air entrance and richening the mixture, so the condition improves somewhat. That doesn't mean that you've got a choke problem.

Some sympthoms of a lean mixture are: Popping exhaust when retaining the engine (mid revs and no throttle), engine overheat, loss of power, acceleration unstable, irregular reving and not going down to idle inmediatly after realeasing the throttle, etc...

(Sorry, it's hard for me to explain in English all those things)

Badbob · 10-16-2007, 05:45 AM

Quote:

Originally Posted by Jaime

(Sorry, it's hard for me to explain in English all those things)

You seem to be explaining it fine to me. Better than I could.

**jonathan180iq** · 10-16-2007, 09:16 AM

I have a good deal of respect for Jaime's knowledge of carbs. He's the one that carried on the re-jetting thread that I so hastily started.

If you look in the "how-to" section, there is a lot of good carb talk. (It may actually be in the "mods" section, I can't remember.) This might lead to some insight into your problem or you may be able to see other symptons previously unspoken of.
There are also some helpful photos in that section.

Jaime said, "Once corrected the problem, you can "shim" the jet needle, not before" He is right. If you start adjusting things in the dark, you'll never know what ONE thing was needed to correct the problem.

Get the carb back to all of it's default settings (this includes making sure that all of the parts are still good, as mentioned by other members) and then adjust one thing at a time. It sounds redundant, but if you made 5 changes and the carb started working properly, you would never know what it was that was actually the problem, or what it was that you "corrected".

**jonathan180iq** · 10-16-2007, 09:23 AM

Quote:

Originally Posted by mcintyre_aerospace

If anyone actually knows where you can buy a mikuni BSR32SS carb, itd help. I cant really spend 350 dollars for one, I only spent around 500 for the entire bike..

Have you tried www.ronayers.com

I use them for all of my factory part needs. They are fairly reasonably priced.

mcintyre_aerospace · 10-17-2007, 11:58 PM

Well I got the carb taken apart, I think the main prob with it was the main jet, in the main throttle body on the engine side. I got a stiff piece of wire to clean it out, and also did the needle shim. Its running pretty strong, despite it being cold outside. I'm gonna ride it a day and see how it does. I still have a slight popping from the exhaust, ill remove it to see what there is to see. I may bring out the welder for another exhaust, don't know yet. Ive taken this carb off enough times to know now the easiest way it to loosen the air box. Two bolts, one visible on the left side, one hidden under the battery holder. Thanks everyone for the advice. Ill try to help people in the future.

**jonathan180iq** · 10-18-2007, 08:44 AM

Popping like afterfire?

Or are you getting the low gear gargle?

If it's the gargle, which I get while just rolling in second gear, you are pretty close to factory.
Afterfire, of course, would mean you are running a little rich and the unburned gas fumes are exploding in the muffler.

10-14-2007, 09:01 PM	#1
mcintyre_aerospace Member Join Date: May 2007 Location: Fort Stockton, TX Posts: 78	Trouble Reving Well I cant really think of a way to sum up my bikes problems. Yesterday I tried to start it, and got nothing at all ,almost ran the battery down trying everything I could. Today I removed the carb and cleaned all the jets and holes and anything I could think of, I also checked the float hight. I reassembled it and put it back on the bike a little while ago. Now the bike sometimes has real trouble starting, but on occasions it'll start right away. The biggest problem I have is that it will not rev past id say about 2000rpm when the choke is off. Somehow it runs with the choke on, i don't really understand why. Third when try and test ride it I hear a lot of popping sound from the muffler. Does anyone out there get any of these kind of problems?? Please help. Login or Register to Remove Ads
	0

10-15-2007, 09:25 AM	#3
Jaime Senior Member Join Date: Jul 2007 Location: Spain Posts: 102	Lean mixture sympthoms. If the carburetor is in good condition, check for any false air entrance to the cylinder or before the carb. When I modified the air filter, the bike wasn't reving over 1/3 throttle and I had to richen the mixture. __________________ Trying my best in English Login or Register to Remove Ads
	0

10-15-2007, 05:24 PM	#5
Jaime Senior Member Join Date: Jul 2007 Location: Spain Posts: 102	You should do a major overhaul of the carb if you haven't completed it already: Check the throttle valve membrane, possibly blocked air jets or fuel valve filter -outside of the carb-, or maybe broken old rubber joints. Also, verify that the intake pike isn't slashed and that there are no air entrances between the carb and the air filter (properly connected oil sump gas tubes). Run the motorcycle with the fuel valve on PRI (or constant fuel supply), to check if the vacuum membrane is damaged and the fuel isn't filling the float chamber. Once corrected the problem, you can "shim" the jet needle, not before. Remember that when you use the choke, you're closing some air entrance and richening the mixture, so the condition improves somewhat. That doesn't mean that you've got a choke problem. Some sympthoms of a lean mixture are: Popping exhaust when retaining the engine (mid revs and no throttle), engine overheat, loss of power, acceleration unstable, irregular reving and not going down to idle inmediatly after realeasing the throttle, etc... (Sorry, it's hard for me to explain in English all those things) __________________ Trying my best in English Login or Register to Remove Ads
	0

10-15-2007, 04:37 PM	#4
mcintyre_aerospace Member Join Date: May 2007 Location: Fort Stockton, TX Posts: 78	Well excuse me, I thought it was about the choke, hmmm. This carburetor isnt as complicated than the ones Ive had on my 302 Tiger, and ive repaired them many times. I guess ill remove the exhaust, check for blocks, and try the needle shim mod. If anyone actually knows where you can buy a mikuni BSR32SS carb, itd help. I cant really spend 350 dollars for one, I only spent around 500 for the entire bike. I guess ill try dealerships, but they allways want a lot. There may be other carbs I can use too. thanks Jaime.
	0

10-16-2007, 09:16 AM	#7
jonathan180iq Super Moderator Join Date: Jan 2007 Location: Dalton, GA Posts: 3,996	I have a good deal of respect for Jaime's knowledge of carbs. He's the one that carried on the re-jetting thread that I so hastily started. If you look in the "how-to" section, there is a lot of good carb talk. (It may actually be in the "mods" section, I can't remember.) This might lead to some insight into your problem or you may be able to see other symptons previously unspoken of. There are also some helpful photos in that section. Jaime said, "Once corrected the problem, you can "shim" the jet needle, not before" He is right. If you start adjusting things in the dark, you'll never know what ONE thing was needed to correct the problem. Get the carb back to all of it's default settings (this includes making sure that all of the parts are still good, as mentioned by other members) and then adjust one thing at a time. It sounds redundant, but if you made 5 changes and the carb started working properly, you would never know what it was that was actually the problem, or what it was that you "corrected".
	0

10-17-2007, 11:58 PM	#9
mcintyre_aerospace Member Join Date: May 2007 Location: Fort Stockton, TX Posts: 78	Well I got the carb taken apart, I think the main prob with it was the main jet, in the main throttle body on the engine side. I got a stiff piece of wire to clean it out, and also did the needle shim. Its running pretty strong, despite it being cold outside. I'm gonna ride it a day and see how it does. I still have a slight popping from the exhaust, ill remove it to see what there is to see. I may bring out the welder for another exhaust, don't know yet. Ive taken this carb off enough times to know now the easiest way it to loosen the air box. Two bolts, one visible on the left side, one hidden under the battery holder. Thanks everyone for the advice. Ill try to help people in the future.
	0

10-18-2007, 08:44 AM	#10
jonathan180iq Super Moderator Join Date: Jan 2007 Location: Dalton, GA Posts: 3,996	Popping like afterfire? Or are you getting the low gear gargle? If it's the gargle, which I get while just rolling in second gear, you are pretty close to factory. Afterfire, of course, would mean you are running a little rich and the unburned gas fumes are exploding in the muffler.
	0