Jump to content

XR600R 1986 XR600R Head, Bore and Transmission Q's

Recommended Posts

I have my 1986 XR600R stripped down and I'm ready to begin the rebuild.   I am doing the 2nd and 5th gear trans mod.  Will most likely bore the cylinder and put a new piston in and then work on the head.  I have a few questions regarding each of these.

#1- On the 2/5 transmission mod as I read through the posts and as I understand it, I will need the 2/5 gears (2nd PN# 23421-MN9-010 & 5th PN# 23491-MW2-780) but I will also need to purchase the adjacent gears to 5 because being newer they have more dogs? So in the pic attached (I hope CongoXR650L doesn't mind me using the pic cause it works great) I would also need C2?  And for someone else possibly looking for the same answer it would apply to any XR/XL pre 88.  I read one post where someone stated the 86 XR600 only had issues with 3rd gear but that is the only one I have read about 3rd being an issue.  I will change the shift springs while I am in there.

#2- I know this question comes with some opinions and is subjective but I would like to know if the 629 kit works well.  I haven't found much of a write up on it, it seems that most jump to the 654 kit instead. I'm not really interested in the 654 kit and I will still have to kick start the thing.  I will be using dual carbs.  My cylinder is currently .50mm over so I will either resleeve to 100mm or I can hopefully bore to 98mm with my current cylinder.  Cost if probably close to the same but what about performance?  I will be adding a cam as well.  I know I have the 650 cylinder option but I'm not sure I want to redrill for pins and the 9mm tap.  I will get the Wiseco or JE piston for it.

#3- Is the XL600 head worth it? Hotcam or other brand?  Considering I follow the two above statements and have a 629 with the 2/5 trans mod, Is the XL head going to get me that much more over my XR head.  If I have to send my head off for work on the center cam channel then I may buy an XL head anyway.  I would rather not run hardened anything on the cam or rockers.  I have read opinions on both ends on the Hot Cams. Is rewelding the stock cam as good? 

As soon as I can decide on what direction to go I'll get some parts ordered and update my other post with progress as I go.  I have been reading about the oil pump issues and will be using some of those ideas and a few of some others and my own as well.

Thanks in advance for the input.

2nd 5th trans mod.jpg

Share this post


Link to post
Share on other sites
18 hours ago, 67chevl said:

I would rather not run hardened anything on the cam or rockers.  I have read opinions on both ends on the Hot Cams. Is rewelding the stock cam as good? 

May want to reconsider that.  

"Hardfaced rocker arms are STRONGLY RECOMENDED with all profiles to prevent damage to cam lobes from worn or chipped chrome plating on used rocker arms."   

Pg. 30     https://www.megacyclecams.com/catalog/catalog.pdf

    Might contact these guys    415 472-3195   FAX 415 472-1497       Megacycle Cams 90 MITCHELL BOULEVARD SAN RAFAEL, CALIFORNIA 94903

GOOD LUCK!

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:


×
×
  • Create New...