im al little scared of my motor

Message

iWantaTurbo · #1 Post by **iWantaTurbo** » Mon Apr 30, 2007 10:11 pm

i don't think it has ever been opened up, and i have put a lot of miles on it. i asked when i got it if he had any of the updates done and he said probly not. i try to change the oil often, but i know the mantnace has not been great on this thing.

don't get me wrong it still runs like the day i got it, and still runs right beside a modded 700 raptor and a piped 450 yamaha

should i take it out and send it to someone and have it rebuilt now, or wait? i would like to add 10 more hp to it at the time of rebuild but i really don't to do any thing right now but what do you think?

cannondale27 · #2 Post by **cannondale27** » Mon Apr 30, 2007 11:58 pm

I think you should but now is riding time.Tough one.Maybe crank is junk by now anyway and if thats case riding it till end of season as long as it doesnt frag nothing will be lost.

iWantaTurbo · #3 Post by **iWantaTurbo** » Tue May 01, 2007 3:05 pm

why would the crank be junk, what goes bad? i got a video of me riding it ill post it later

kdeal · #4 Post by **kdeal** » Tue May 01, 2007 3:55 pm

C27 has always taken some verbal abuse for recommending changing the crank rod bearing from the get go, so I will answer this one. The factory connecting rod bearing is a poor choice for the application from the factory. We as a group have been replacing them with a connecting rod bearing from a Z400 motor. The bearings are identical except the Z400 bearing will not "eat" into the rod journal like the stock bearing does. For a reason unknown to most of us the factory bearing and crank has been known to last anywhere from 5 hours to a couple hundred hours (yes there are a few of them). The arguement has always been whether to drop the motor and fix the problem immeadiately or ride it until it breaks. Replacing it before it breaks does not always promise to be cheaper as the connecting rod and crank may be scored too bad to be reused. At that point you are looking at $400 minimum to replace or repair the problem. If they are reusable, you are looking at about $100 total. If you ride it until it breaks you will probably spend more money as you will definitely be replacing several other parts (crankshaft, piston kit, etc). This is not to mention the mess of metal that will now be strewn throughout your motor and worst yet the frame (oil tank). This can take several hours to flush and get back to usable condition. I have taken apart several motors with crank failures, and none were a cheap fix. I have recently took apart two motors that were new or close to it and needed less than $200 in parts to make them fully updated.

Food for thought: Ask the people who think you should ride the bike until it breaks, would they put a stock crank bearing back into their rebuilt Cannondale motor? I have yet to find anyone who would. So the thought is universal that the stock rod bearing is junk. We only disagree on when to fix it.

Let the flames begin!!!!!!!!!!!!!!!!!!!

thedeatons · #5 Post by **thedeatons** » Tue May 01, 2007 4:28 pm

I fixed mine before it broke for $115... But then again, you never know when they will break and whether they are even fixable! Tough call.... Honestly though I would do it now, before you HAVE to replace other parts due to a failed crank.

MyCannibal · #6 Post by **MyCannibal** » Tue May 01, 2007 8:13 pm

kinda off topic but I thought the Z400 bearing had more rollers than our stock?....

kdeal · #7 Post by **kdeal** » Tue May 01, 2007 9:55 pm

QUOTE (MyCannibal @ May 1 2007, 04:13 PM) <{POST_SNAPBACK}>

kinda off topic but I thought the Z400 bearing had more rollers than our stock?....

I believe you are correct. I think the extra rollers and design keep the Z400 bearing from scoring the crank like the stocker does. The stock bearing will eat into the crank, it's only a matter of time.

kdeal · #8 Post by **kdeal** » Tue May 01, 2007 9:56 pm

QUOTE (MyCannibal @ May 1 2007, 04:13 PM) <{POST_SNAPBACK}>

kinda off topic but I thought the Z400 bearing had more rollers than our stock?....

I believe you are correct. I think the extra rollers and design keep the Z400 bearing from scoring the crank like the stocker does. The stock bearing will eat into the crank, it's only a matter of time.

iWantaTurbo · #9 Post by **iWantaTurbo** » Tue May 01, 2007 10:19 pm

so i can take it out right now and send it out and have it fixed for $200 if the crank is good and $500 ish if the crank is bad?

a stock motor is around 32 hp right? what would it cost to get to 40 or 50 hp???

cannondale27 · #10 Post by **cannondale27** » Wed May 02, 2007 12:50 am

Very well put Kdeal agree fully.

iwanaturbo if you update the crank and its good yet piston and sleeve are still good yet.Get yourself a open filter setup,exhaust and port the head and you could easily get 50hp out of it.Probably for less than $1000 with exhaust.Lots of options and variables all affect price.Timbo is who you talk to about porting and if crank is good there are a couple places doing them including Timbo.If its bad then you need to decide on keeping stock stroke or more stroke.If going stock stroke talk to BlackWidow for a new crank.Stroking it talk to Timbo.Doing the assembly work yourself will save you a ton.Help is here.