Yamaha Discussions about Yamaha ATVs.

Help on1987 225 moto 4

Thread Tools
 
Search this Thread
 
Old Aug 13, 2013 | 03:27 PM
  #1  
storman's Avatar
Thread Starter
|
Weekend Warrior
Joined: Oct 2011
Posts: 5
Likes: 0
Unhappy Help on1987 225 moto 4

I got this thing not running. Took head off and intake valve bent in open position. They had taken thing apart to fix low power. Put new valve in, But.. The arrow on emergency rope pull and book say it should turn counter clockwise looking at it from left side of unit. As you start to turn from TDC position counter clock wise exhuast valve opens first on down stroke.... that ant right....Could they have mixed up valve rocker arms when they took it apart? I don't want to bend new valve.. Timing is lined up on T mark on fly wheel and line on cam gear . Does unit really turn counter clock wise from left side looking at it?? help! please
 
Reply
Old Aug 13, 2013 | 09:10 PM
  #2  
Raptor450's Avatar
Pro Rider
I ride, because football, basketball, and baseball only uses one ball!
Joined: Dec 2006
Posts: 2,407
Likes: 0
Default

If the arrow and the book say it's supposed to turn counter clockwise then I would trust it. I don't see how anyone could have gotten the rocker arms mixed up but that would not make the valves open incorrectly. I would be more worried about having the correct cam installed, if it's wrong that would do what you're talking about, but that normally wouldn't happen, i'm not even sure cams could be interchangeable like that. You could always turn the engine with a wrench a couple of rotations to make sure nothing binds up, you'll know real quick if the valves hit the piston, the engine should spin fairly free. Just don't spin the engine with the starter until you know for sure everythings right. If anything is wrong, I would say it's your timing, make sure the piston is at the top by sticking a screwdriver or something down the sparkplug hole when the crank is at tdc and make sure the valves are 100% closed and have some play in the rocker arms when the piston is at tdc.

I'm a little rusty but if I remember correctly the magneto goes around twice for every one rotation of the crank, so it is possible for the "T" to show but the piston is at the bottom of the cylinder, so make sure the piston is definitely at the top when the T is visible. This would cause your timing to be 180 degrees off.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
wendal
Yamaha
28
Aug 3, 2024 10:03 PM
scman843
Yamaha
1
Jun 18, 2017 10:21 PM
fredrikrosen
Chinese Quads
14
Oct 29, 2016 07:56 PM
zPuls3
1) Engine problems..
5
Sep 12, 2015 08:54 AM
mrmickman123
Technical and How-To Articles
0
Aug 30, 2015 10:37 PM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 



All times are GMT -5. The time now is 05:41 PM.