P700 Camshaft replacement help

D

Dylan23

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Jul 11, 2019
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  1. Big Red
Okay so I have a MUV700 aka big red the pioneer 700s cousin. My camshaft is going out hold throttle half way in neutral and cuts out when driving has no power etc. I adjusted the valves last week to see if that helped and when I finished it did had more power and wouldn’t cut out the other day it started back I guess the adjustments are out again. So my question is has anyone ever changed there’s out and do you have any tips or does anyone know if there is a video or a step by step tutorial. I got the service Manuel just didn’t know if there was anybody with first hand experience with this! Thanks in advance!!
 
H

HondaTech

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It's pretty simple really, get the engine on TDC before ever pulling it apart. Makes it easier to time after the fact. You'll need to drain the coolant as well.

The head will need to come off since the camshaft sits under it.

Study the cam buckets closely as well, most likely they'll be damaged as well.

Make sure to loosen the valve adjusters before reinstalling since theyll be too tight with the new cam being at full height. Oh and don't drop the chain down in the crankcase.
 
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Dylan23

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  1. Big Red
It's pretty simple really, get the engine on TDC before ever pulling it apart. Makes it easier to time after the fact. You'll need to drain the coolant as well.

The head will need to come off since the camshaft sits under it.

Study the cam buckets closely as well, most likely they'll be damaged as well.

Make sure to loosen the valve adjusters before reinstalling since theyll be too tight with the new cam being at full height. Oh and don't drop the chain down in the crankcase.

I was reading the service manual and it said remove the throttle body do you have to remove it also?
 
H

HondaTech

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I was reading the service manual and it said remove the throttle body do you have to remove it also?

Yeah in order to remove the head the exhaust and throttle body will need to be taken off. I usually just unbolt the airbox and slide the whole assembly backwards a little. Then I unbolt the entire exhaust from the machine and lay it to the side, so I dont have to mess with taking the header off the muffler.
 
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Dylan23

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  1. Big Red
Yeah in order to remove the head the exhaust and throttle body will need to be taken off. I usually just unbolt the airbox and slide the whole assembly backwards a little. Then I unbolt the entire exhaust from the machine and lay it to the side, so I dont have to mess with taking the header off the muffler.

I may have bit off more than I can chew here lol I dont know if I feel confident enough to do all this. I am pretty handy with a wrench but digging in a motor is pretty intimidating around how much would a honda dealership charge to do this?
 
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Dylan23

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  1. Big Red
Yeah in order to remove the head the exhaust and throttle body will need to be taken off. I usually just unbolt the airbox and slide the whole assembly backwards a little. Then I unbolt the entire exhaust from the machine and lay it to the side, so I dont have to mess with taking the header off the muffler.

Ok got everything removed including throttle body and exhaust did like you said and just slid the whole air box assembly back and removed the muffler. I'm going to go in the motor tomorrow and wondered if there is anything special I should do or be looking for or just follow the service Manuel pretty much? Also do I need to remove the thermostat or just the coolent hose running to it I already removed the hose but didn't know if I needed to actually remove the thermostat for some reason. I appreciate all your help with this by the way!
 
H

HondaTech

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Ok got everything removed including throttle body and exhaust did like you said and just slid the whole air box assembly back and removed the muffler. I'm going to go in the motor tomorrow and wondered if there is anything special I should do or be looking for or just follow the service Manuel pretty much? Also do I need to remove the thermostat or just the coolent hose running to it I already removed the hose but didn't know if I needed to actually remove the thermostat for some reason. I appreciate all your help with this by the way!

Removing the hose is the only thing needed.

You'll need something to disengage the cam chain tensioner or you can remove it from the engine entirely, but risk needing to replace the gasket.

A tiny flat blade screwdriver will do yo release it, it doesnt need to be released the entire time just when removing and installing the chain off and on the camshaft.
 
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Dylan23

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  1. Big Red
Removing the hose is the only thing needed.

You'll need something to disengage the cam chain tensioner or you can remove it from the engine entirely, but risk needing to replace the gasket.

A tiny flat blade screwdriver will do yo release it, it doesnt need to be released the entire time just when removing and installing the chain off and on the camshaft.

Well I got the cam shaft off yesterday and the exhaust side lobe was almost round so found my problem! Couple more questions for you when I install the new one I know it has marks on the camshaft to make sure you put the chain on right is there a trick to doin this or is it pretty straight forward? Second when I screwed in the cam chain tensioner it never released and stayed turned in to back this off do you just turn counter clockwise or did I not turn it in all the way chain was a little hard to come off? Thanks for all the help!
 
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HondaTech

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Well I got the cam shaft off yesterday and the exhaust side lobe was almost round so found my problem! Couple more questions for you when I install the new one I know it has marks on the camshaft to make sure you put the chain on right is there a trick to doin this or is it pretty straight forward? Second when I screwed in the cam chain tensioner it never released and stayed turned in to back this off do you just turn counter clockwise or did I not turn it in all the way chain was a little hard to come off? Thanks for all the help!

The lines on the cam will be even with the surface of the head at TDC.

Sounds like you may need a tensioner as well, its trying to stick.
 
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Dylan23

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  1. Big Red
The lines on the cam will be even with the surface of the head at TDC.

Sounds like you may need a tensioner as well, its trying to stick.

Ok the tensioner is spring loaded right? So it should of went back tight when i let off pressure from the screwdriver?
 
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H

HondaTech

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Ok the tensioner is spring loaded right? So it should of went back tight when i let off pressure from the screwdriver?

Yeah, they usually sound like a clacking or knocking that's inconsistent when it starts going bad.

Common on the 700 platform.
 
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Dylan23

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  1. Big Red
Yeah, they usually sound like a clacking or knocking that's inconsistent when it starts going bad.

Common on the 700 platform.

Got everything put back together this weekend and man that thing is a whole new machine. I bought it used from one of my buddies and it has WAY more power than when I bought it. I let my buddy drive it and he said its got more power than when he had it. Leads me to believe this cam shaft has been going for a long time. Thanks HondaTech for all your help it was greatly appreciated!! If anyone has any questions about this feel free to shoot me a message and I will try to help I feel like I know my way around this machine now!
 
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Reloder28

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Oct 21, 2018
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Deer Park, Tx
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  1. 700-2
Okay so I have a MUV700 aka big red the pioneer 700s cousin. My camshaft is going out hold throttle half way in neutral and cuts out when driving has no power etc. I adjusted the valves last week to see if that helped and when I finished it did had more power and wouldn’t cut out the other day it started back I guess the adjustments are out again. So my question is has anyone ever changed there’s out and do you have any tips or does anyone know if there is a video or a step by step tutorial. I got the service Manuel just didn’t know if there was anybody with first hand experience with this! Thanks in advance!!

I have first hand experience with grammar, punctuation & spelling.
 
R

Reloder28

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Oct 21, 2018
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  1. 700-2
Looks like someone has jokes! I am sorry didn't know I needed someone to proof read my message before posting it. Move along if you have nothing positive to add to this post.

Moving along.
 
SWB

SWB

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I have first hand experience with grammar, punctuation & spelling.


From what I understand you are only suppose to use &. When joining two companies or partnerships together such as a law firm Howard & Stern or AT&T, to name a couple.
 
M

mt1950

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  1. Big Red
Honda should be ashamed of themselves from the most trouble free powersports to one that can't even go 6000 miles and needs the cam replace and the valve adjustment is considered maintenance oh yeah I have to replace mine also Honda was no help at all. The dealerships around me have a 4-6 week waiting period to even diagnosis it...
 
DG Rider

DG Rider

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Honda should be ashamed of themselves from the most trouble free powersports to one that can't even go 6000 miles and needs the cam replace and the valve adjustment is considered maintenance oh yeah I have to replace mine also Honda was no help at all. The dealerships around me have a 4-6 week waiting period to even diagnosis it...
Plenty of them go far, far over 6000 miles and never have an issue. It's unfortunate that this happens, but the majority are just fine. What I'd like is a definitive answer from Honda as to why it happens, so we can take steps to avoid it.
Valve adjustment is a normal maintenance item. There are still a lot of cars out there that are supposed to have adjustments. Nobody ever does them.
 
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M

mt1950

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  1. Big Red
This one was never abused driving by my wife mostly around the place for work. No EFI car produced requires valve adjustment as a standard maintenance that I know of. And if you research this problem on the Honda MUV700 it is a lot more common than you think.
 
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