2003 Ktm 300mxc

[griffbones]

Hey guys, I am going on Monday to pick up a new to me 2003 300MXC that I believe to be in very nice condition. I will be using this bike for recreational woods riding, no MX, no racing, just technical woods stuff just for fun.

I have read that some years of 300MXC's had some jetting issues, is the 2003 one of them? Maybe the previous owner has it jetted well, but I don't know yet.

Is there any thing else about this particular bike that I should look for? I know about the basics like top end maintenance, air filters, trans oil, etc...... I am just wondering about things specific to this model and year of KTM.

Thanks in advance fella's

 

[jrf4x4]

Check out www.ktmtalk.com

 

[griffbones]

Thank You.

 

[Shaw520]

Model related,... the MXC has the tranny and SOME of the power delivery of a race bike,.. that can sometimes be a handfull in the more technical trail situations.
Not to dispair,... power delivery can 'made to fit' through simple jetting and powervalve adjustment.

 

[griffbones]

Say the guy that I am buying the bike from tells me that he just installed a new Wiseco piston and rings and a high compression head. He claims that I can still run 91 octane pump gas in the bike. He is including the stock head in the deal too.

1. Now I just read on KTM talk.com that Wiseco's are a bad idea in KTM's? Why would this be, I have used them with very good results in Jap bikes for years.

2. Do you think I can still run pump gas? (I don't know who made or modified the head, so I realize this could be a hard one to answer)

3. What would be the purpose of installing the higher compression head?

4. I couldn't find much specific on the rumored jetting issues on this particular model, can you guy's shed any light on that side of this year and model?

I hope I am not getting myself into a mess here. I was pretty confident about the purchase until I read some of this stuff over at KTM Talk.com.

Any thoughts fella's?

 

[Shaw520]

Im not sure I'd believe everything the seller told you unless you personally know him. Putting a 'high comp' head and telling you to run pump gas is contradictive. High comp head would be used to create more high RPM power, more designed for desert or MX racing, not something that would suit the type of woods riding you've described.

I would try and get things back to stock, it will be alot less complicated to tune, and more user/woods friendly.

 

[OKKX'er]

Search for "squish band" on KTMTalk. The tolerances the 300 heads were made with left many with more room between the piston at TDC and the head than optimum. Correcting this made them much easier to jet, plus more torque. If the head was only corrected, the compression wasn't raised and pump gas is fine. If even more material was removed, raising the compression, you may need race gas. Given the amount of power in a 300 with the correct squish, there is a good chance they stopped before adding more compression.
Go to an auto parts store and buy a compression tester. Test your motor ( throttle wide open), and record the value. All low-cost testers vary in absolute PSI, but your can retest periodically and this will help decide when you need a top end. Search KTMTalk for compression to learn more.

 

[griffbones]

Turns out the previous owner had the "Clay Mod" done? Some guy named Clay at Munn Racing, I guess does some kind of upgrade to the KTM heads to enhance performance, but still allows use of pump gas.

The guy swears I will love the low end power of this bike for lugging around in the woods. I realize this is still a two stroke and you can't idle them all day long, but I like the idea of having some lugging capability for the tight woods and steep ditches where I ride. An acquaintance of mine has a 2000 300MXC that he still races; he said that he loves his 300 for use as a woods bike, so I hope I like this one too.

Going to look at it tomorrow and hopefully bring her home if it is as nice as the previous owner is claiming. Wish me luck!