bike is destroying carb seals and o rings!?



35 replies to this topic
  • ramcharger

Posted September 04, 2015 - 12:50 PM

#21

Haha...Partly out of guilt since I bailed on him in the chat last night out of frustration, I thought I'd give it another shot to help out since he is only 16...But now I feel like we're going to find out he's actually 18 but uses a birth certificate that says he's 16 because of a witness protection program or something, haha...Crazy info keeps popping up after the questions are partially answered.

im actually 16. the story is just long and confusing of the bike. ill just tell the whole story in one big paragraph. I bought the bike from my buddy last year and had a new rod, rod bearings, crank bearings, water pump shaft, coil, wiring harness, piston, cam chain, all new gaskets put in. Then when my buddy had it he had a shop give it new valves, valve springs, cams, clutch, had cylinder redone at millenium, and had the carb rebuilt. But when the shop rebuilt the motor when i brought it to them they kept having carb problems so they ordered a used carb. So when i picked it up there it started first kick and ran great, then i get home and i couldnt start it. so the next day me and my buddy tried push starting it and after about 30 min we got it running and it ran good. so i shutted it off and brought it to a different shop to find out the timing was off, it had way to much oil in it, and the o rings and everything rubber in the carb was eaten away. 



  • ramcharger

Posted September 04, 2015 - 12:52 PM

#22

so now im stuck with a non running bike that i just stuck 1300 into the motor and it dont run



  • Krannie McKranface

Posted September 04, 2015 - 01:24 PM

#23

Dude, any FCR 41 mx/cr carb will work on that bike. 

Nearly very carb'd dirtbike from 2003 to 2011 used one.

 

The newer 450 carb you bought....of of ebay?  Yes, they sell junk if you don't know where to buy or what to ask before buying.

 

The slide does NOT fit tight into the bore, as there is a slide plate and seal the regulates vacuum.

 

If there are no 'wheel trenches' in the bore, it will be fine. 



  • Aka.Goose

Posted September 04, 2015 - 04:27 PM

#24

Yeah, sorry man, I'm still under the impression it's something other than your carb...And I swear I'm not trying to bust your balls, but things just still aren't quite adding up...Something isn't being conveyed or overlooked..The reason I say that is that "started first kick and ran great, then i get home and i couldn't start it" doesn't make sense to me...I would think that if a shop ordered you a used carb and then installed it and got it dialed in so well as to where it starts first kick, I would think they had a pretty good overview of the carb (and I bet all the seals are shot because either the seller or the shop cleaned that used carb with carb cleaner spray)...But then you say it was running good after push starting for 30 minutes?!? Say what? You shut it off after it was running well, but then couldn't re-start it? and then brought it to a different shop than the one that had it running first kick before you brought it home? If the timing was off, it wouldn't have been running at all...I'm still under the impression that the one thing that may have been overlooked on the rebuild is the cam tensioner, maybe when you brought it home and when you didn't kick it over as smoothly as the mechanic that probably already had the bike start method for that bike dialed in, after repeated attempts the cam chain skipped...Now, how after trying to push start it for 30 minutes it would be possible to realign back to correct timing instead of have the out of time valves slap the shit out of the piston, I have no idea, lol...But you say it ran well, but then just wouldn't start, so I don't know man, just guessing here at this point...


Edited by GOOSE 07 YZ450F, September 04, 2015 - 04:34 PM.


  • ThumpMe

Posted September 05, 2015 - 05:46 AM

#25

Haha...Partly out of guilt since I bailed on him in the chat last night out of frustration, I thought I'd give it another shot to help out since he is only 16...But now I feel like we're going to find out he's actually 18 but uses a birth certificate that says he's 16 because of a witness protection program or something, haha...Crazy info keeps popping up after the questions are partially answered.

 

 You guys are killing me! HA!

 

 Ethanol eats up rubber. That is a fact. Look at the pump face. I believe it is law they post what percentage of ethanol each pump is using.  

 

 Most are at a max of 10% although this gubbament wants to push that to 15% even though most car manufacturers are stating that will void the engine warranties! That will not stop the useless madness of ethanol subsidies and greedy gov't  though.

 

 Check around to see where people using outboard motors or chainsaws are buying their gas as most towns have someplace where you can get no-ethanol fuel as  small engibes seem to hate it the most.

 

 As for cab wear. I have never ever worn a carb out....yet.....and I have put LOTS of miles on lots of scooters.  I imagine it can happen but you are going to have to have a boatload of miles on one to see enough wear to adversely effect  a carb, or be running it without an air cleaner.



  • grayracer513

Posted September 05, 2015 - 10:05 PM

#26

Dude, any FCR 41 mx/cr carb will work on that bike. 

 

 

The 400+cc YZF line has always used 39mm carbs, not 41's.  The 41's will work if properly retuned, but the FCR-MX 39 that I recommended will drop in place with very little work, and a YZ400 will run very nicely on stone stock YZ450 jetting.  It's a far simpler solution for most beginners.  

 

 

 

 As for cab wear. I have never ever worn a carb out....yet.....and I have put LOTS of miles on lots of scooters.  I imagine it can happen but you are going to have to have a boatload of miles on one to see enough wear to adversely effect  a carb, or be running it without an air cleaner.

 

The early FCR carbs were quite prone to wear at the bottom corners of the vacuum release plate, and in the corresponding lower corners of the slide bore.  They also have a nasty habit of gumming up the internal passageways between the upper and lower body, and when they get into that condition, they're a major PITA to straighten out.  Mileage doesn't have much to do with it, particularly the second problem.



  • ThumpMe

Posted September 06, 2015 - 12:11 AM

#27

 

The early FCR carbs were quite prone to wear at the bottom corners of the vacuum release plate, and in the corresponding lower corners of the slide bore.  They also have a nasty habit of gumming up the internal passageways between the upper and lower body, and when they get into that condition, they're a major PITA to straighten out.  Mileage doesn't have much to do with it, particularly the second problem.

 

 

 I have never had any problems with slides  on any of my bikes. What do you think causes/starts it? Do you think the wear is caused or started  by a poor size fit or a bad casting? Or do you think it is due to the casting or slide wearing from one material being harder then the other? That is why I had stated dirt getting into it like it would get from running no air filter or a real dirty one might have something to do with that.

 

 I have had the internal passages gum up, on bikes as well as chainsaws, boat motors, log splitters, trucks, etc., mostly due to this garbage "they" are forcing us to use called gasoline!  I have also learned the best way to prevent this from happening is to be sure to start up each and every machine at least every 3-4 weeks especially if sitting (like during the Winter). That or drain the gas out. If you try to go much longer than that without starting them up you WILL get good at cleaning out carbs. 



  • grayracer513

Posted September 06, 2015 - 06:26 AM

#28

Dirt can play a part in it, but the early FCR bodies were also soft, and bigger thumpers put a lot of pressure on a closed or near closed slide during the intake stroke.  Wear in the area depends a lot more on the cumulative number of openings and closings and intake cycles than mileage. 



Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • ramcharger

Posted September 06, 2015 - 06:48 AM

#29

Yeah, sorry man, I'm still under the impression it's something other than your carb...And I swear I'm not trying to bust your balls, but things just still aren't quite adding up...Something isn't being conveyed or overlooked..The reason I say that is that "started first kick and ran great, then i get home and i couldn't start it" doesn't make sense to me...I would think that if a shop ordered you a used carb and then installed it and got it dialed in so well as to where it starts first kick, I would think they had a pretty good overview of the carb (and I bet all the seals are shot because either the seller or the shop cleaned that used carb with carb cleaner spray)...But then you say it was running good after push starting for 30 minutes?!? Say what? You shut it off after it was running well, but then couldn't re-start it? and then brought it to a different shop than the one that had it running first kick before you brought it home? If the timing was off, it wouldn't have been running at all...I'm still under the impression that the one thing that may have been overlooked on the rebuild is the cam tensioner, maybe when you brought it home and when you didn't kick it over as smoothly as the mechanic that probably already had the bike start method for that bike dialed in, after repeated attempts the cam chain skipped...Now, how after trying to push start it for 30 minutes it would be possible to realign back to correct timing instead of have the out of time valves slap the shit out of the piston, I have no idea, lol...But you say it ran well, but then just wouldn't start, so I don't know man, just guessing here at this point...

the second mechanic thought it was just hard to start bc it had way to much oil in it



  • Aka.Goose

Posted September 06, 2015 - 07:04 AM

#30

the second mechanic thought it was just hard to start bc it had way to much oil in it

Go back to the guys that had it running first kick...

I've never heard a mechanic say a bike is hard to start because it has too much oil in it...Sure it can damage the motor, blow seals/gaskets, blow a bunch of oil out your breather, etc...but be the reason it's hard to start? huh?

So, OK, you brought it to a different shop than the one that had it running first kick (why you didn't go right back to the shop that had it running first kick after you couldn't start it, I can't figure out). And this new shop told you there was too much oil, timing was off, and carb seals were shot...So what did they do?



  • ramcharger

Posted September 06, 2015 - 07:20 AM

#31

Go back to the guys that had it running first kick...

I've never heard a mechanic say a bike is hard to start because it has too much oil in it...Sure it can damage the motor, blow seals/gaskets, blow a bunch of oil out your breather, etc...but be the reason it's hard to start? huh?

So, OK, you brought it to a different shop than the one that had it running first kick (why you didn't go right back to the shop that had it running first kick after you couldn't start it, I can't figure out). And this new shop told you there was too much oil, timing was off, and carb seals were shot...So what did they do?

i didnt go back to the shop that had it running bc he wont do anything about it bc he said it ran good when i left. Then the new shop re set the timing and said he cant get new seals for the carb so then i would have to buy a different used one and i dont have money right now to buy a used one right now



  • ramcharger

Posted September 06, 2015 - 07:22 AM

#32

does anyone know if a yz250f carb would work on it or just the 450



  • Aka.Goose

Posted September 06, 2015 - 07:43 AM

#33

Gray will have to verify this, but no, I'm pretty sure the 250 is a 37 and the 450 is a 39...You are getting hosed by both mechanics (don't know if it's because you're young, or went to the shop with hot-head parents, or what)...But any mechanic I know would WANT the bike back if he just fixed it and you couldn't get it running...It's common and not a big deal to miss something that didn't present itself on inspect and tests, and it's normal for something ELSE to break or go wrong after fixing a different problem...I'm surprised he didn't simply say, bring it back in, let's see what's up...If your response from him was , "Get lost kid, it ran fine when it left here" there is again more to the story you aren't telling us...And then this new guy, "can't start because too much oil?!?" but the timing was off? Can't repair a carb that was just purchased used and ran fine? Can't order OEM seals? Say what? So he fixed the timing, changed oil and couldn't get it started then told you this bike needs it's 3rd carb!?!

Dude, get a service manual and start at page 1, you aren't out 1300 bucks, you just need to put time in and do it right yourself...You obviously must not have access to a decent mechanic.



  • ramcharger

Posted September 06, 2015 - 10:11 AM

#34

Gray will have to verify this, but no, I'm pretty sure the 250 is a 37 and the 450 is a 39...You are getting hosed by both mechanics (don't know if it's because you're young, or went to the shop with hot-head parents, or what)...But any mechanic I know would WANT the bike back if he just fixed it and you couldn't get it running...It's common and not a big deal to miss something that didn't present itself on inspect and tests, and it's normal for something ELSE to break or go wrong after fixing a different problem...I'm surprised he didn't simply say, bring it back in, let's see what's up...If your response from him was , "Get lost kid, it ran fine when it left here" there is again more to the story you aren't telling us...And then this new guy, "can't start because too much oil?!?" but the timing was off? Can't repair a carb that was just purchased used and ran fine? Can't order OEM seals? Say what? So he fixed the timing, changed oil and couldn't get it started then told you this bike needs it's 3rd carb!?!

Dude, get a service manual and start at page 1, you aren't out 1300 bucks, you just need to put time in and do it right yourself...You obviously must not have access to a decent mechanic.

the reason the mechanic wouldnt stand by it bc hes been working on it for 5 months and has never got it right. every time he told me it was good to go id go their ride it and give it back to him bc it would never run right. Then it finally runs good once their then wont start when i get home and he dont stand by his work



  • ramcharger

Posted September 06, 2015 - 10:13 AM

#35

and the second carb the shop ordered was a 250 carb not a 450 carb. could that be my problem?



  • Aka.Goose

Posted September 06, 2015 - 10:38 AM

#36

:banghead:







Related Content

Wiki
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info


Articles
  • 0 replies
Forums
Photo

Michigan Motocross Tires by 288yz450


Dirt Bike   Dirt Bike Regional Discussion   North
  • 1 reply
Forums
Photo

YZ450F 03 Sparks driving me crazy by SirAttard


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 5 replies
Forums
Photo

Is it worth it? (Cam and High compression piston) by macgi77


Dirt Bike   Make / Model Specific   Honda   CRF 150/230 F/L
  • Hot  36 replies
Forums
Photo

Megabomb Fitment by 288yz450


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply
 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.