Runs Rough 6500-8500 rpm

[dwcdds93]

I went out for my first ride of the year last weekend after doing a lot of modifications. I discovered a few issues during the weekend. First, it starts and idles good. Runs good till 6500 rpms, then very rough (spittering and popping) till 8500 rpms, then runs great again. If you punch the throttle, no roughness is felt. This is a problem considering trail riding and playing off trail seems to fall right in this rpm range. I will be removing the carbs to clean them, but should I do any adjustments while they are off? It seemed that this started last year after I installed a CPR filter kit and clutch, but has intensified this year. The instructions involved changing the main jets, springs, and needle position.

Next, when at wot, the rpms jump to 10500, then fall to about 10000. I haven't had the chance to run for a long wot burst, but it dropped from where it was last year due to the 144" track and 7 tooth 2.86 pitch drivers. The CPR clutch kit I have uses Heavy Hitters clutch weights. What adjustments can be made to bring the rpms back to the 10400-10600 range that is recommended?

Thanks for any advice.

 

[Len Todd]

You might try a new secondary spring. They last about a year. A fall off of RPMs is symptomatic of a bad spring.

Clean the carbs and make sure you have fresh fuel going into those clean carbs. Are you sticking to 87 Octane fuel?

Have you checked you throttle free play lately. Could you be getting a TORS?

 

[dwcdds93]

Len, thanks for the reply. Yes to the 87 octane fuel. As far as the secondary spring, it only has about 1000 miles on the one that came in the clutch kit. If I replace it, which one and where do I find one?

As far as the throttle free play, I am not sure what this means. I have heard mention of TORS, but still don't completely understand what it is. Will this only happen at a particular rpm? It runs great before and after the 6500-8500 rpm range.

 

[Len Todd]

Do you have an Owner's Manual. TORS is explained it in.

Here is a link to an Owner's Manual Site. Click here for Owners Manuals

With the throttle in the idle position, is there a gap between the flipper and its mount? That gap is the measurement for throttle free-play. If there is no gap, the throttle free-play is inadequate. The throttle has a switch in it. It detects the lack of free play. With no free-play, the switch closes the circuit that tells the ECU that there is something wrong with the throttle. Then the ECU will cut the motor's RPM down. It feels like it is missing.

Seeing how you are not familiar with TORS, this is a good thing for you to check and it may just fix your problem.

But, I suspect you also need a carb cleaning.

 

[standard]

So is the "gap" for throttle free play adjusted at the flipper end, or adjusting the cable length down by the carbs.?



With the throttle in the idle position, is there a gap between the flipper and its mount? That gap is the measurement for throttle free-play. If there is no gap, the throttle free-play is inadequate. The throttle has a switch in it. It detects the lack of free play. With no free-play, the switch closes the circuit that tells the ECU that there is something wrong with the throttle.

 

[Len Todd]

The throttle free-play is adjusted by lengthening or shortening the throttle cable housing at the bracket near the top of the carbs.

The free-play is measured at the flipper. You need about 1/8" of gap between the flipper and the mount, where the cable goes through.

If you think you are having a problem with TORS, you can bypass it by disconnecting it down by the delta frame where it breaks out of the harness to go to the carbs. Plug the harness's two conductors into each other and leave the carb harness dangle. This will bypass TORS. Do this only for testing. Restore TORS when you are done testing. TORS is a critical safety feature.

TORS is explained in the Owner's Manual. Do you need an Owner's Manual?

 

[RedRocket]

Here is the page right from the 2003 RX-1 Service Manual for adjusting throttle free-play:

Click thumbnail for larger image.

Also, here is a picture of the wires to disconnect to bypass the TORS. Disconnect the two coming from the harness and plug them into each other.

Click thumbnail for larger image.
PM me your email address and I will show you where to download the service manual in PDF format.

 

[macgregor]

mine runs fine '04 rx1, idles and starts perfectly, pulls hard and accelerates to about 125kms and then feels like if you try to press on past that, it just has no more in her, the tach is showing about 8,000 RPM, doesn't seem to go past that, read here where I should see 10,000 or 10,500, she never seems to get up to that, does this sound like a good candidate for a new secondary spring?.....thanks Cheers Greg.

Secondary Spring? is this something that is easily changed? what is involved and is it a fairly cheap part?

thanks.....cheers Greg

You might try a new secondary spring. They last about a year. A fall off of RPMs is symptomatic of a bad spring.

Clean the carbs and make sure you have fresh fuel going into those clean carbs. Are you sticking to 87 Octane fuel?

Have you checked you throttle free play lately. Could you be getting a TORS?

 

[Len Todd]

I assume you have a drive belt that is within spec and you have the correct Belt height adjustment.

Clean your carbs first. Let the jets soak for a while in carb cleaner. See the attached Tips for Carb Cleaners and Carb's exploded view Drawing files.

If you have never replaced the Secondary Spring, it is past time to replace it. Also, while you have the secondary apart you may want to inspect the Secondary's Ramp Shoes (Item # 2 on the attached Secondary) File. See attached Secondary Inspection Procedure.

How may miles do you have on the sled. You may need to clean and inspect the Primary Clutch. Take look at the Roller's and Weight's bushings, etc. Check the gap between the Primary's Sliders (Item # 10 on the attached Primary File.)

But, I'll bet your biggest gain will be had by cleaning the carbs.

 

[macgregor]

Hello Len;

I can't believe that you have already, read and responded and with details and attachments to boot, you are an amazing wealth of info......I will look at all the douments and will definetly do the carb cleaning, I am the second owner and there is 8100kms on the sled now, can't confirm if any of the work on the clutch has been done either, so a secondary spring maybe in order too....thanks for all the info to look at, its gonna take me some time to sort through all this stuff, probably should have pulled the carbs off and cleaned them prior to the start of the season. Obviously I am fine to run it the way it is correct?, I won't do any harm to it right, and I can take it apart at my liesure and at best clean the carbs as you say, it should be in my best interest.....cheers Greg

Clean your carbs first. Let the jets soak for a while in carb cleaner. See the attached Tips for Carb Cleaners and Carb's exploded view Drawing files.

If you have never replaced the Secondary Spring, it is past time to replace it. Also, while you have the secondary apart you may want to inpect the Secondary's Ramp Shoes (Item # 2 on the attached Secondary) File. See atteched Secondary Inpection Procedure.

How may miles do you have on the sled. You may need to clean and inspect the Primary Clutch. Take look at the Roller's and Weight's bushings, etc. Check the gap between the Primary's Sliders (Item # 10 on the attached Primary File.)

But, I'll bet your bigest gain will be had by cleaning the carbs.

 

[Len Todd]

You should be O.K. to run it as is for a while. Have fun!

 

[macgregor]

10-4, thanks again Len, going to run it like this for a bit until I get used to the beast, its new to me, I bought it last may '09 and first tiem I am able to ride it is now, so far I have only put on 220kms this season, the rx-1 still has me on "break-in" ;-).....I am learning to tame the beast, but its a much different ride and machine than my '02 vmax 600 tripple thats a given. I mean if I hadn't been reading all the info here, I wouldn't even know there was more to expect from this machine, it runs fine the way it is to me, and it goes plenty fast enough for me in a straight line, I am curious down the road to see what its like when I get it dialed in and running at its best!.

cheers Greg.

You should be O.K. to run it as is for a while. Have fun!