ok so i have a bent valve and was told that i would have to do an engine rebuild. where do i start? do i get all new valves? where do i get them from? piston rings? is it worth the money? all i wanna do right now is cry. my 929 was/is my only source of transportation. i went out riding the other day and since the temp switch is bad i hooked up a manual switch and forgot to turn the fan on while i was riding and the bike was running hot all day which caused the valve to go to ****. any input will greatly be appriciated!!

 

why touch the bottom end if there isn't any damage? bottom end can make things get expensive - very quickly


and how hot was the motor running? how hard did you run the motor (rev). what was the ambient temp?


and how did you diagnose bent valves?


you can buy replacement heads off of ebay or fix yours with new valves, valve guides, and seals.



i mean, you didn't drop a valve did you? (because that would certainly destroy the entire motor)

 

well i was told its most likly a valve.. i forgot to turn the fan on while i was riding.. temp was usally around 220-230. first thing im gonna do is pull the throttle body off and clean it out and hhave someone sync it.. if it still runs bad then.. idk.. problem is its laggin getin to 70 mph.. after that it wont go above 75mph and it sputters.. kinda sounds like a lawnmoer.. i guess ill have to check compression while in the works.

 

230 is not overheating.
Sounds like you have a different issue. Are all 4 cylinders firing?

 

Hey. Chettoboy I have a 954 engine that would fit perfectly in your 29 and ecu and cluster .

 

told by who?



230 wouldn't bend a valve - and the gauge would have thrown a red light at 250

 

I don't know about the valve issue but you have your manual fan switch wired wrong if you have to turn it on/off because it would otherwise stay running all the time with the key off. If you wire it to a power source that is only hot when you turn the key on then you can leave the switch in the ON position all the time until you get the temperature switch replaced.

I did a "how-to" on adding a manual fan switch to the 1000RR. Your wiring may be similar. What it does is it switches a ground signal to the fan relay, since the +12V is always there. The computer normally sends the ground signal to the relay when it reaches a certain temp but the manual switch turns it on whenever you want. The bonus of doing it this way is that if you leave the switch in the ON position the fan still turns off when you turn the key off. Plus, it will still come on when it reaches a certain temp, even if the manual switch is in the OFF position. The "how-to" article is in the 1000RR section if you want to read it.

Custom Fan Switch for 08+ CBR 1000RR

 

ok so it is not a bent valve. it was a throttle body issue. one of the black screw on seals that holds this small valve was broken. I'm gonna try to put pics up soon. so I took it apart completely cleaned it up and put it back together but for some reason now it's only running on 3 cylinders. I'm going to take it apart again and brain storm for a bit. this time I'm going to test all the injectors and take more pics. worst case scenario I need a new throttle body and fuel rail. stay tuned.

how can I change the subject of this thread? Since I'm not rebuilding the engine. mechanic said the engine is in great shape, problem is the throttle body/ rail/ sensors

some questions I have, how can I test the fuel pressure regulator, map sensor? what should I look out for in rebuilding the throttle body? and I believe I lost the thrust spring. what purpose does that have and do I really need it?

 

What do you want it to say?

 

bad FPR - the fuel pump does shut off when the key is in the on position before you start it, rough idle, bad mpg, etc.