Jump to content
Sign in to follow this  

Rebuild time

Recommended Posts

I am do for a rebuild on my bike. I haven't actually pulled it apart yet to see exactly whats wrong. Just trying to get some info together. Searched and found some answers but not all.

1) It won't start cold unless I bump start it.

Valves zeroed out. I was thinking about sending my head out to CRF Heads to have it redone. I was thinking about the $599 package. http://crfheads.com/ How is their work? Another place that you would recommend?

2) While it's apart I was going to do the piston anyway but also because in about 4 hrs run time it burns about half way between the high and low marks on the dip stick. Not much but more than it ever used to. I was going to go with CP piston 13.5:1 stock bore. What is the difference between the standard piston and the project x piston? Also, where is a good place to buy them, I haven't found many places that sell them.

Other parts/things to get:

Cam chain, cam chain tensioner, 08 cam

Any other tips for the rebuild?

Share this post


Link to post
Share on other sites

How many hours are on it? That helps us to help you. May want to think about replacing the crank on it also. The 13.5:1 will give it more power through out the entire range. CP is now Moose so look for a Moose piston. JE, Wiesco are about the same quality piston with the CP, so don't hold yourself to just the CP. Loosing oil is a pretty good symptom of needing a rebuild or some work period. Could be a valve guide or valve seal that's helping it to burn some of the oil. On the head, maybe someone else will help you out with that part, I don't know anything about crfheads. The 07 head is a real good candidate for porting if not the best year for porting.

Share this post


Link to post
Share on other sites

There's about 100 hrs on it. It doesn't smoke on start up and no visible smoke while riding but it's definantly using oil. I've owned it new since Sept. 2009 and have never touched anything internally but oil changes. Oil changed with amsoil and filter about every 6 hrs. Lemme know if there is anything else you need to know to help out.

Share this post


Link to post
Share on other sites

O yeah it has only been trail ridden exept one time to the track but was my first time to a track so not ridden hard.

Share this post


Link to post
Share on other sites

Personally, I'd replace the crankshaft. Never know when it's going to go and with 100 hrs on it, better to be safe than sorry. At that point, you have a completly rebuilt engine. They sell crankshaft kits that come with the crankshaft, main bearings, oil seals and lower end gasket set on e-bay for around $225. It's great insurance!

Share this post


Link to post
Share on other sites

So is the bike being ridden hard? If it is CRF Heads looks like it would be a good option. If you are to just going to be taking it easy on the trails, you could also check out bigborethumpers.com.

Share this post


Link to post
Share on other sites

Well I would say it's being ridden fairly hard since I am a big hill climbing fan. Alot of full throttle climbs.

Share this post


Link to post
Share on other sites
Well I would say it's being ridden fairly hard since I am a big hill climbing fan. Alot of full throttle climbs.

Do yourself a favor and replace the crank. You'll thank me later! Nothing worse than it going out in 10 hrs after you just rebuilt the top end.

Share this post


Link to post
Share on other sites

I think I am def going to replace the crank. Trying to keep the cost around $1200. How is porting with keeping the 07 cam? Plans are still 13.5:1 piston, crfheads valve/port job, replace crank. I will be doing the work myself. Also Charlie C the crank setup you were talking about, is it a hotrods crank? Hotrods about the same quality as OEM?

Share this post


Link to post
Share on other sites
I think I am def going to replace the crank. Trying to keep the cost around $1200. How is porting with keeping the 07 cam? Plans are still 13.5:1 piston, crfheads valve/port job, replace crank. I will be doing the work myself. Also Charlie C the crank setup you were talking about, is it a hotrods crank? Hotrods about the same quality as OEM?

It was actually a Wiesco crankshaft kit. They're all about the same quality until you start getting into the high dollar connecting rods like Falicon or Carillo. I'm pretty impressed with the Wiseco so far. Before I install them, I have them checked to make sure they are assembled correctly, and so far they've been 100% on the money.

The 07 cam is fine. The 08 cam would be better with an 07 ported head.

Share this post


Link to post
Share on other sites

Your not worried about having to run race gas with the 13.5-1 compression ratio? Pump gas wont work. Call Je, Wiseco or CP, they will tell u NOT to use pump gas. And yes, people on here are gonna tell you its "ok" but I would trust the people who actually engineered the piston, and take their advice over random people on an internet forum. Sorry if thats kinda harsh, its not meant to be. I just cant type my tone of voice. haha

Edited by ridered4life250
spelling

Share this post


Link to post
Share on other sites
Your not worried about having to run race gas with the 13.5-1 compression ratio? Pump gas wont work. Call Je, Wiseco or CP, they will tell u NOT to use pump gas. And yes, people on here are gonna tell you its "ok" but I would trust the people who actually engineered the piston, and take their advice over random people on an internet forum. Sorry if thats kinda harsh, its not meant to be. I just cant type my tone of voice. haha

They'll tell you to run race gas to cover their a$$. It's perfectly fine to run pump fuel. A minimum of 91 octane with 13.5:1 compression, but I recommend running 93 minimum. I've been building these engines for a good number of years and so far in my experience and a lot of others including one of the most respected names in the industry, (which I won't mention because he'll probably read this and comment), it's fine. Everyone is entitiled to their opinion and you're right, these are just random people on an internet forum, but, I can speak from experience and running numerous engines without the fear of detonation which is where the high octane fuel plays a role. If you have 8 dollars a gallon to blow because it smells good, hats off to you! I don't, so I run 93 and I have for years without any issues what so ever.

And I'm not being a smartass, just voicing my experience, not opinion!

Share this post


Link to post
Share on other sites

OK to run GOOD quality pump gas 91-93 octane up to 13.5:1. This ASSUMES the jetting is correct though. You need to run higher octane if you go higher than that on compression ratio. Notice I avoided the term race gas, since race gas comes in virtually any octane. Not sure I'm spelling octane right though...

Share this post


Link to post
Share on other sites

In my area all the high test is 93 octane so I'm good there. I'll check out the Wiseco crank. Since jetting was brought up, with the mods that I'm doing will there be a change in jetting? I don't have any problem tuning a carb just wondering if that is something I will have to look for. Trying to get all my ducks in a row before tax returns. haha

Share this post


Link to post
Share on other sites
In my area all the high test is 93 octane so I'm good there. I'll check out the Wiseco crank. Since jetting was brought up, with the mods that I'm doing will there be a change in jetting? I don't have any problem tuning a carb just wondering if that is something I will have to look for. Trying to get all my ducks in a row before tax returns. haha

Unless you're doing some major porting work, jetting will not come into play. May be just a little tweaking but that's about it.

Share this post


Link to post
Share on other sites

Ok that's good to know. Still looking for anyone that has any comment on the CRFHeads work.

Share this post


Link to post
Share on other sites

I would also like to know how the CRFHeads work! I read their stuff and it seems like a good idea. Kind of expensive though.

Share this post


Link to post
Share on other sites

Just a small update, bought a crank yesterday from ebay, Wiseco $192.95 shipped. Its a top seller on there and he has 25 more I think. Great deal bearings, bottom end gasket kit and seals.

Share this post


Link to post
Share on other sites

Also decided I'm getting the 08 cam and just getting the valves redone still might go with crfheads.com but the cheaper package that doesn't have porting. For that I need the 08 springs and retainers and everything else is the same? Just making sure.

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:

Sign in to follow this  

×