2005 Yamaha RX one lacking power on top end

[mikecorwin]

Hello last season I purchased a 2005 Yamaha RX1 with 2000 miles on it. It drove flawlessly for the first few days but towards the end of my trip, it felt that it wasn't providing as much power on the top end, as it was the first few days. I was very amazed with how strong it pulled when the secondaries opened I believe, but the feeling completely went away, and it did not pull how it did before. It's still felt fine in the lower rpm and lower speeds but not nearly as fast as it was before. I am open to all advice and comments. I have the sled in my garage ready to dive in. I appreciate any comments you have. Thank you

 

[CaptCaper]

Isn't that year carbureted? Maybe old gas got in to the jets. Obvious things to do which you probably did was drain old gas. Add Gumout cleaner for a few tanks.
Worse case clean the jets etc. The fuel today wreaked havoc on all my carburated machines since it came into my life. Nasty stuff.

 

[thrasher]

I would definitely be looking at your clutches and belt. These machines eat drive belts. After high speed runs, the clutches get very hot and the belt gets glazed and slips or explodes. Check the status of the slide buttons on your secondary. You may want to lightly sand the faces of the primary and secondary if highly polished. Try a new belt or deglaze your old belt if shiny and polished. If none of these, then something robbing power from your engine.

 

[mikecorwin]

I would definitely be looking at your clutches and belt. These machines eat drive belts. After high speed runs, the clutches get very hot and the belt gets glazed and slips or explodes. Check the status of the slide buttons on your secondary. You may want to lightly sand the faces of the primary and secondary if highly polished. Try a new belt or deglaze your old belt if shiny and polished. If none of these, then something robbing power from your engine.

Thank you very much for the input. I will definitely check this. Are there any other common things to check that would rob power while I'm looking at the clutches?

 

[mikecorwin]

Hello last season I purchased a 2005 Yamaha RX1 with 2000 miles on it. It drove flawlessly for the first few days but towards the end of my trip, it felt that it wasn't providing as much power on the top end, as it was the first few days. I was very amazed with how strong it pulled when the secondaries opened I believe, but the feeling completely went away, and it did not pull how it did before. It's still felt fine in the lower rpm and lower speeds but not nearly as fast as it was before. I am open to all advice and comments. I have the sled in my garage ready to dive in. I appreciate any comments you have. Thank you

Now that I'm thinking about it, I towed my brother home, and then after it started acting this way

 

[thrasher]

That could do it. You may just have to clean things up a bit clutch and belt wise.

 

[mikecorwin]

That could do it. You may just have to clean things up a bit clutch and belt wise.

The belt is 2 mm skinnier than a new spec one. I also discovered the secondary clutch has a lot of In and out play from what I’ve read it is normal. When I look up the parts schematic, it shows 2 .5 mm spacers between the bolt head washer and the collar inside of the clutch housing where the splines are and mine only has one. Should I add a second one? Separate to that, I’m opening the carburetors right now and under the diaphragm cap there is a very small O-ring and someone installed one of the caps backwards at one point and the O-ring was missing. Could this do anything? My brother tells me he remembers it bogging in the mid range.

 

[RobX-1]

Between the missing o-ring and your RX-1 having carbs (ie. not fuel injected), I would also suggest going thru the carbs, disassemble, clean jets and re-sync. These carbs have small jets that get easily plugged where running fuel treatment doesn't always work. Although you don't have to remove the carb rack, I opt to when servicing the carbs on my RX-1. And yes, missing one of those o-rings can cause issues as there were numerous post back in the day where guys were removing the caps and the slide springs pops the cap off and the o-ring goes for a ride.

 

[mikecorwin]

Between the missing o-ring and your RX-1 having carbs (ie. not fuel injected), I would also suggest going thru the carbs, disassemble, clean jets and re-sync. These carbs have small jets that get easily plugged where running fuel treatment doesn't always work. Although you don't have to remove the carb rack, I opt to when servicing the carbs on my RX-1. And yes, missing one of those o-rings can cause issues as there were numerous post back in the day where guys were removing the caps and the slide springs pops the cap off and the o-ring goes for a ride.

Greatly appreciate your input and knowledge. How would you recommend I re-sync the carburetors I know they make kits I can buy one which screw do I turn to make the adjustments and do you have any good videos you can recommend or just some kind of a walk-through

 

[RobX-1]

If you become a VIP, you'll have access to a service manual with pictures to go along with the sync process. Some guys say its not needed but if you remove the jets and needle valves and such, IMO it's a must. As for the following steps, they can be found using the Search button from prior posts but was something I saved along with all the other helpful information Freddie of ECP provided in his posts before his passing. Hope it helps:

warm the engine up good before connecting the manometer. Make sure the engine idle speed once warmed up is between 1200 and 1450 RPM's. If it is not raise or lower the idle to this specification. Shut engine off when it is good and warm, then disconnect the 2 black hoses going to the #1 and #4 intake manifold. Connect these 2 hoses together as this is what operates your fuel pump. A small piece of tubing of some kind works nicely for this. This will prevent the pumps from going airbound thereby giving you a little more time to run the engine off of what is in the float bowls only. The other alternative would be to hang an auxilliary fuel tank up and use this as your fuel source by connecting these 2 hoses via a "T" to the auxilliary fuel source. If you are reasonably efficient, you can usually get the carbs synch'd before running the float bowls dry. Okay, so now the #1 and the #4 hoses are connected from the manomometer to the intake manifolds spigots located at the top of each manifold directly in front of the valve cover. Next, remove the black rubber plugs on the #2 and the #3 intake manifolds and connect the remaining 2 lines from the manometer to these. Note that the manometer (If you bought it from me anyways) is numbered. You should put the cylinders corresponding to the number for each number on the manometer. Start the engine and let it idle. if all 4 mercury tubes are even within a small amount or very close there is no need to adjust anything. Start by adjusting the # 2 carb to the #3 carb. The adjusting screws are located between each carburtor and are a phillips head screwdriver configuration. There are 3 phillips head screws for doing this. One is between carb 1 and 2 one is between carb 2 and 3 and another between carb 3 and 4. The reason there is only 3 on a 4 cylinder engine is due to the fact that when you make an adjustment, you are adjusting one carb up and one carb down. Perform the same procedure for the #3 and the #4 carbs. These phillips head screws can be seen by looking straight down between each carburetor. If a cylinder is showing high on the manometer, adjust the screw counterclockwise. Note that you will not only be lowering that carb but also raising the one next to it so slight movements are only necessary. If it is low try moving the adjusting screw clockwise. Give then engine a few "raps" of the throttle between each adjustment to allow the engine to "stabilize" to the new setting. High revs are not required so be very careful not to allow the clutch to engage. A quick tip too...when you press down on the screwdriver to adjust each carb, you will actually change the snych due to the fact that you are pressing on the adjustor. Don't let this fool you. Make a small adjustment and remove the screwdriver pressure from the adjusting screw and give it a moment to respond to the new setting. Reconnect all your hoses to their appropriate locations and reinstall the plugs for the to #3 and #4 manifolds. Try to get the carbs synch'd within .19 PSI of each other. Also, it is good to know that your valve lash is within the factory tolerance. Adjusting valve lash changes the manifold pressure thereby changing the carburetor synchronization. You are done.

All you are doing is matching the other three carbs to the base carb. Base carb is # 3 in an RX-1. You do not need to worry about setting all the carbs to a specific setting. It is very helpful to have a 4 tube manometer because all the carbs interact and the mercury is bouncing around to much to get a specific reading. You just want all 4 tubes equal. The throttle cable is connected to Carb #3. The bolt to adjust #2 is right next to the throttle cable. That makes #1 on the PTO side and #4 on the mag side.

 

[RobX-1]

As for a carb sync, I have one of the ole school 4-carb mercury Motion Pro carb sync tools. Was not a fan of their liquid blue enviro friendly crap and jumped on the mercury one when I found it many years back.

 

[mikecorwin]

If you become a VIP, you'll have access to a service manual with pictures to go along with the sync process. Some guys say its not needed but if you remove the jets and needle valves and such, IMO it's a must. As for the following steps, they can be found using the Search button from prior posts but was something I saved along with all the other helpful information Freddie of ECP provided in his posts before his passing. Hope it helps:

warm the engine up good before connecting the manometer. Make sure the engine idle speed once warmed up is between 1200 and 1450 RPM's. If it is not raise or lower the idle to this specification. Shut engine off when it is good and warm, then disconnect the 2 black hoses going to the #1 and #4 intake manifold. Connect these 2 hoses together as this is what operates your fuel pump. A small piece of tubing of some kind works nicely for this. This will prevent the pumps from going airbound thereby giving you a little more time to run the engine off of what is in the float bowls only. The other alternative would be to hang an auxilliary fuel tank up and use this as your fuel source by connecting these 2 hoses via a "T" to the auxilliary fuel source. If you are reasonably efficient, you can usually get the carbs synch'd before running the float bowls dry. Okay, so now the #1 and the #4 hoses are connected from the manomometer to the intake manifolds spigots located at the top of each manifold directly in front of the valve cover. Next, remove the black rubber plugs on the #2 and the #3 intake manifolds and connect the remaining 2 lines from the manometer to these. Note that the manometer (If you bought it from me anyways) is numbered. You should put the cylinders corresponding to the number for each number on the manometer. Start the engine and let it idle. if all 4 mercury tubes are even within a small amount or very close there is no need to adjust anything. Start by adjusting the # 2 carb to the #3 carb. The adjusting screws are located between each carburtor and are a phillips head screwdriver configuration. There are 3 phillips head screws for doing this. One is between carb 1 and 2 one is between carb 2 and 3 and another between carb 3 and 4. The reason there is only 3 on a 4 cylinder engine is due to the fact that when you make an adjustment, you are adjusting one carb up and one carb down. Perform the same procedure for the #3 and the #4 carbs. These phillips head screws can be seen by looking straight down between each carburetor. If a cylinder is showing high on the manometer, adjust the screw counterclockwise. Note that you will not only be lowering that carb but also raising the one next to it so slight movements are only necessary. If it is low try moving the adjusting screw clockwise. Give then engine a few "raps" of the throttle between each adjustment to allow the engine to "stabilize" to the new setting. High revs are not required so be very careful not to allow the clutch to engage. A quick tip too...when you press down on the screwdriver to adjust each carb, you will actually change the snych due to the fact that you are pressing on the adjustor. Don't let this fool you. Make a small adjustment and remove the screwdriver pressure from the adjusting screw and give it a moment to respond to the new setting. Reconnect all your hoses to their appropriate locations and reinstall the plugs for the to #3 and #4 manifolds. Try to get the carbs synch'd within .19 PSI of each other. Also, it is good to know that your valve lash is within the factory tolerance. Adjusting valve lash changes the manifold pressure thereby changing the carburetor synchronization. You are done.

All you are doing is matching the other three carbs to the base carb. Base carb is # 3 in an RX-1. You do not need to worry about setting all the carbs to a specific setting. It is very helpful to have a 4 tube manometer because all the carbs interact and the mercury is bouncing around to much to get a specific reading. You just want all 4 tubes equal. The throttle cable is connected to Carb #3. The bolt to adjust #2 is right next to the throttle cable. That makes #1 on the PTO side and #4 on the mag side.

Amazing thank you so much. Couldn’t find that information anywhere. I will do this the first chance I get. Just going to order some parts and o rings, how reliable are the ignition coils on these machines should I get a new set they are original? And what are you opinions on OEM va aftermarket for the coils

 

[RobX-1]

Also, regarding the vac lines to the fuel pumps, I just bought a plastic T so that I could connect the sync tool line and the fuel pump line together so as to have as much as time you need (ie. will not be running the fuel bowls dry).

With you having an 05, your coils should be good. It was the 03-04 that were notorious for arching. If you are concerned, start sled at night and open hood and see if you see any light shows. On my 03, I did have to replace two of then and when doing so, ordered the superseded (2005) ones.

 

[mikecorwin]

Also, regarding the vac lines to the fuel pumps, I just bought a plastic T so that I could connect the sync tool line and the fuel pump line together so as to have as much as time you need (ie. will not be running the fuel bowls dry).

With you having an 05, your coils should be good. It was the 03-04 that were notorious for arching. If you are concerned, start sled at night and open hood and see if you see any light shows. On my 03, I did have to replace two of then and when doing so, ordered the superseded (2005) ones.

Thank you for the tip about the tee that’s the right way to do it for sure. Just out of curiosity how does this little o ring on the diaphragm bowl work the channel it sits in his recessed, but there is no pathway into the carburetor?

 

[RobX-1]

Not sure of its use exactly. Just know my 08 Kodiak 450's carb cap has the recessed area for the o-ring but does NOT have the o-ring.