You do not remove the head, you go through the plugs in the valve cover. You must first make sure the engine is at TDC (top dead center) on the compression stroke by viewing through the inspection plug. I would highly recomend getting a service manual, they are very usefull for regular maintence as well as a rebuild. I just got my sons 250 rebuilt about a month ago it runs great. The manual is a must have for work like this, you can get it from your dealer for less than $50.

 

I just got a service manual for my 300 4X4 from www.repairmanual.com
It was $36.00 shipped to my door.

Now that I am armed with the manual I want to adjust my valves. I have everything I need to do it, except the knowledge to determine TDC on the compression stroke. The manual says to remove the timing inspection plug, but doesn't show where it is at. I see a rubber plug on the left side of the head. Is that it? And how do you know if you are on the compression stroke?

 

No that is not it on the side of the head. It is a 17mm I think down on the case on the shifter side about 11:00 position. It will be on the flat part of the cas3e allmost top, right next to the cylinder. To determine TDC just remove the spark plug and rocker cover plugs. Turn the engine over with e the pull rope or remove the pull starter to turn it over. I find it easier to just remove the pull starter and turn the crank it's self. feel for the intake valve to operate go down then when it comes back up watch in the timing plug for the TDC mark. This is very important that you get it at TDC. When it is at TDC both valvs will be loose you should be able to feel them. Check it out and if you need anymore help just ask.

 

Mudcat,

You said to ask if I need more help. Well I need more help!!

I messed around with it for several hours today and feel like I am missing something. I am able to find TDC. I felt for the intake valve to operate and then come back up. As soon as it comes back up I can feel looseness in both valves. I then bring it to TDC and there is absolutely no looseness in either valve. They are both up but are not loose. There is no gap at all. Am I missing something here? When they need adjustment is it usually because they are too tight or too loose?

Thanks

 

Yes it is possible that your valves have gotten too tight. The 250 and 300 seem to have this problem. Just make sure you are on the compression stroke and at TDC. Then adjust to the correct specs. Like I have said before the 250 and 300 need valve adjustment about every 500 miles or so. It never hurts to check them. Most idle and cold starting problems can be eliminated with a valve adjustment. The 400 and 500 need very little adjustment, they just seem to hold their specs better.

 

I got it figured out. I wasn't on the compression stroke. I adjusted them to what I hope is right. I know that the intake is correct, it's the exhaust that was hard to get at and get the feeler in at the correct angle. If anything it is maybe just a little bit too much. The manual gives .005 intake and .010 exhaust. Is there a tolerance range like on the 400/500?


Thanks for the help mudcat!

 

I believe there is a tollerence range, but I don't have my service manual here right now. Glad to be of some help, that is what these boards are for. Good luck, and ride safe.