Polaris ATV Forum
Go Back   Polaris ATV Forum > Polaris ATV Technical Discussions > ATV Repair and Maintenance

ATV Repair and Maintenance Having problems? Doing a rebuild? All Repair/Maintenance Discussions here.

Reply
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old 06-03-2013, 06:09 AM
neal860's Avatar
Junior Member
 
Member #36641
Join Date: Jun 2013
Location: Nova Scotia Canada
Posts: 4
800 EFI Engine problems

I recently had the Camshaft and lifters go in my 2011 sportsman 800 EFI at 151 hours and a little over 2k KM it (about 1000 miles). The machine was of coarse out of warranty so I decided to do the fix myself, I have been working on small engines all my life rebuilding many motorcycles snowmobiles and ATV's so it was not a big deal to me.

Of coarse i purchased a service manual before taking on the task.

First I will tell you that you CAN do this without pulling the motor but the 2 head bolts will give you a bit of a problem to get out. I wont go into the details oh doing the job but I wanted to let everyone know what I am going through with this machine.

When installing the CAMSHAFT the service manual clearly states to use the dots stamped on the gears for timing, there is no other way to do this and if the dots are lined up then there is no way it could be out of time. well in my case they were WRONG .. in going by the dots the engine ran like crap back firing through the intake. I then tore it down again to double check the mark alignment and doubble check the service manual, I put it back together again with same result. the third time I took it apart i noticed a spot of red paint on one of the teeth on the crank gear. I decided to try that tooth instead of the one with the DOT on it and it ran perfect.

After going through that it worked like a new one again .. but that was short lived .. I ran the engine 5 hours and changed the oil and filter .. then again at 15 hours (to make sure there were no filings left in the engine anywhere)

Now I have an issue that the first start of the day (after setting all night) it will start up and idle normal .. however if you touch the throttle at all it dies immediatly .. then the engine had 0 compression in both cylinders . after setting for 15 min or so it will start up again .. this process will repeat unless you let the engine idle and warm up for at leaf 15 min (way too long). then it will Work like a new one all day long with no issues and has 180psi compression in each cylinder.

I have sense taken the head off again and checked all the Valves and springs, there are no bends and they all move as normal . I would say it seems like the cylinders are washing out but the plugs are dry when this happens and if you leave it idle until the fan kicks in then it doesn't do it.

Anyway im still troubleshooting this (next step is maybe planing the head) I think it might be leaking a bit of Antifreeze in the jugs from the head gasket when it sets.

Oh and by the way ... Polaris claims to not have any issue with the CAMS in these engines .. yet I know of another machine like mine within 10 miles that had the same issue and the CAM was on back order for 4 weeks when I ordered it.
Attached Thumbnails
800 EFI Engine problems-img_1045.jpg   800 EFI Engine problems-img_1041.jpg  

Last edited by neal860; 06-03-2013 at 07:43 AM. Reason: Adding Photos
Reply With Quote
Sponsored Links
PolarisATVForums is the premier Polaris ATV Forum on the internet. Registered Users do not see these ads, So Register, It's Free!
  #2 (permalink)  
Old 06-03-2013, 04:49 PM
Bruce!'s Avatar
Super Moderator
Premium Member
 
Member #193
Join Date: Feb 2009
Location: Port Angeles WA
Posts: 19,500
Welcome to the board!
Reply With Quote
  #3 (permalink)  
Old 06-03-2013, 05:13 PM
polman500's Avatar
Polaris ATV Legend
 
Member #1958
Join Date: Nov 2009
Location: SE Kentucky
Posts: 2,692
Hmm...problem with the compression release? or perhaps hydraulic lifters sticking till warmed up?
Reply With Quote
  #4 (permalink)  
Old 06-03-2013, 05:44 PM
neal860's Avatar
Junior Member
 
Member #36641
Join Date: Jun 2013
Location: Nova Scotia Canada
Posts: 4
I was thinking the lifters might have been sticking too ... but i tried this in the morning withe the valve cover off and can see all the rockers moving normal.

I didnt know there was a decompression on these .. is there?

Thanks for your input

- Neal
Reply With Quote
  #5 (permalink)  
Old 06-04-2013, 09:59 AM
CHRISH8846's Avatar
ATV Enthusiast
 
Member #35641
Join Date: Apr 2013
Location: West Bloomfield MI 48323
Posts: 41
Just from a car stand point it sounds like you have way too much cylinder clearance when cold and as the eng finally starts and warms up the clearances get tighter so it starts ok when finally warmed up.
__________________
2006 800EFI just stock stuff
Reply With Quote
  #6 (permalink)  
Old 06-04-2013, 11:04 AM
neal860's Avatar
Junior Member
 
Member #36641
Join Date: Jun 2013
Location: Nova Scotia Canada
Posts: 4
I havent checked the clearance on it yet as i didnt pull the jugs completely off, I figured it was washing out somehow.

Also these engines are strange in the fact that both pistions are side by side instead of staggered

But I can go out cold and it has 180psi on compression test ... I will have to make a video and post it .. its a strange beast

Thanks
Reply With Quote
  #7 (permalink)  
Old 06-07-2013, 04:08 AM
CHRISH8846's Avatar
ATV Enthusiast
 
Member #35641
Join Date: Apr 2013
Location: West Bloomfield MI 48323
Posts: 41
If it has 180 cold no amount of gas would wash the cylinder walls enough to cause no compression. You have to have some mechanical problem causing no compression(broken cam etc.) or you have compression all the time and some other problem.
__________________
2006 800EFI just stock stuff
Reply With Quote
  #8 (permalink)  
Old 06-07-2013, 09:41 AM
turboshelby's Avatar
Extreme ATV Enthusiast
 
Member #35082
Join Date: Mar 2013
Location: Nebraska
Posts: 172
Oil pressure relief sticking can cause things like this, also could help to explain such early wear in cam and lifters.
Reply With Quote
  #9 (permalink)  
Old 06-07-2013, 04:37 PM
Corey850XP's Avatar
Extreme ATV Enthusiast
 
Member #15824
Join Date: Jun 2011
Location: Nova Scotia
Posts: 237
Hi, if you need top end parts, I have an 800EFI junked.
Reply With Quote
Reply

Lower Navigation
Go Back   Polaris ATV Forum > Polaris ATV Technical Discussions > ATV Repair and Maintenance


Search tags for this page
2013 polaris 800 engine problems
,
2013 polaris ranger 800 problem
,

2013 polaris ranger 800 problems

,

2013 sportsman 800 efi problems

,

polaris 800 efi problems

,

polaris 800 engine problems

,
polaris 800 snowmobile problems
,

polaris 800 sportsman problems

,

polaris ranger 800 efi problems

,

polaris ranger 800 engine problems

,
polaris ranger 800 problems
,
ranger 800 efi 800
Click on a term to search our sites for related topics.

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
2012 850 xp Engine Problems BaronVonBo Polaris XP 9 04-28-2014 04:22 PM
Search engine problems trukwest Site Issues & Suggestions 1 03-04-2013 08:05 PM
Hot engine problems stacey05sportsman500 ATV Repair and Maintenance 4 07-14-2011 04:57 PM
Newbie with engine problems Vahoagie ATV New Members 5 11-11-2010 03:56 AM
05 500 ho sportsman engine problems blackbowtie98 ATV Repair and Maintenance 9 06-06-2009 07:01 AM

Motosport.com


All times are GMT -8. The time now is 03:00 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.