Long story
#31
I wanted to update my old thread.
I fixed the problem with the low idle and stalling at low revs - I did a valve clearance check and found that 14 of the 16 valves were out of spec. I changed the shims to put the valves within spec, and replaced all the vacuum tubes while I had the throttle bodies off. Put everything back together and it ran like a champ; the revs went up and down quickly and the throttle response was excellent.... for about a week.
I went to test ride the bike last night and it was running like the plugs were fouled; it was bogging down when I try and pull away from a stop and when I gave it some gas it would back fire. Sure enough, I took the plugs out again this afternoon and they are black with soot, plus cylinder 3 and 4 plugs were also wet with gas.
Does anyone have any idea why this keeps happening? I have replaced the FPR, I have tested the fuel injects, I took a voltmeter to the TPS and its within spec, the battery measured 13.2V with the bike off. I have a clone slip-on exhaust muffler, but thats the only non OEM mod to the bike. I have been through scores of old posts on this site an others and the only answer seems to be that these bikes just do that.... I can't accept that answer. There's no way that a healthy CBR should need the plugs pulling and cleaning once a week after very light use. What do I check next? What am I missing? Any advice is greatly appreciated. Thanks.
I fixed the problem with the low idle and stalling at low revs - I did a valve clearance check and found that 14 of the 16 valves were out of spec. I changed the shims to put the valves within spec, and replaced all the vacuum tubes while I had the throttle bodies off. Put everything back together and it ran like a champ; the revs went up and down quickly and the throttle response was excellent.... for about a week.
I went to test ride the bike last night and it was running like the plugs were fouled; it was bogging down when I try and pull away from a stop and when I gave it some gas it would back fire. Sure enough, I took the plugs out again this afternoon and they are black with soot, plus cylinder 3 and 4 plugs were also wet with gas.
Does anyone have any idea why this keeps happening? I have replaced the FPR, I have tested the fuel injects, I took a voltmeter to the TPS and its within spec, the battery measured 13.2V with the bike off. I have a clone slip-on exhaust muffler, but thats the only non OEM mod to the bike. I have been through scores of old posts on this site an others and the only answer seems to be that these bikes just do that.... I can't accept that answer. There's no way that a healthy CBR should need the plugs pulling and cleaning once a week after very light use. What do I check next? What am I missing? Any advice is greatly appreciated. Thanks.
#32
#33
UPDATE.
I wanted to close out this thread as I solved the problems.
The rich running was due to the ECM not working correctly. It would allow the bike to start and run, but did not appear to be processing any inputs from the MAP, air temp, or coolant temp sensor.... when these were unplugged there were no FI codes from the ECM. I bought a replacement on eBay and the bike now runs perfectly.
To summarize: the rough running at idle was solved with a valve clearance adjustment, and the rich running was solved with a replacement ECM.
Thanks everyone for your help with all of these issues.
I wanted to close out this thread as I solved the problems.
The rich running was due to the ECM not working correctly. It would allow the bike to start and run, but did not appear to be processing any inputs from the MAP, air temp, or coolant temp sensor.... when these were unplugged there were no FI codes from the ECM. I bought a replacement on eBay and the bike now runs perfectly.
To summarize: the rough running at idle was solved with a valve clearance adjustment, and the rich running was solved with a replacement ECM.
Thanks everyone for your help with all of these issues.
#34
UPDATE.
I wanted to close out this thread as I solved the problems.
The rich running was due to the ECM not working correctly. It would allow the bike to start and run, but did not appear to be processing any inputs from the MAP, air temp, or coolant temp sensor.... when these were unplugged there were no FI codes from the ECM. I bought a replacement on eBay and the bike now runs perfectly.
To summarize: the rough running at idle was solved with a valve clearance adjustment, and the rich running was solved with a replacement ECM.
Thanks everyone for your help with all of these issues.
I wanted to close out this thread as I solved the problems.
The rich running was due to the ECM not working correctly. It would allow the bike to start and run, but did not appear to be processing any inputs from the MAP, air temp, or coolant temp sensor.... when these were unplugged there were no FI codes from the ECM. I bought a replacement on eBay and the bike now runs perfectly.
To summarize: the rough running at idle was solved with a valve clearance adjustment, and the rich running was solved with a replacement ECM.
Thanks everyone for your help with all of these issues.
Glad you finally got it figured out, and I hope you get some nice fall days to enjoy it before winter really sets in!
#35
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