[Dtrain412]

First time post on here, this site has been a go to for the last month.
The issue I have is that I bought an 05 CRF250R for my kid from a guy at work, the bike was literally stripped completely down due to throwing the rod through the case. His dad had replaced the L & R cases and had the lower end already built. I finished putting the rest together. Short end of story is got everything back together, put oil and trans oil in bike. Went and put coolant in the radiator and it took the whole bottle which is double the capacity. Decided to check trans and oil and found it all went into the oil. I am by all means no motorcycle mechanic but I am a mechanic by trade. I am looking for some guidance on where to start or replace or the culprit. Thanks in advance!

[JimDirt]

Welcome to the site !!

There could be a few places coolant can go thru the system , possibly case halves not sealed , possibly the dowels for the cyl/head not installed or bent ... possibly the head not flat/warped , water pump shaft seal , head gasket/base gasket issue , old gasket piece left on a spot .....Those would be the first ones I can think of ..... , but unless there is a breach from a cracked part (head , cylinder) damaged when the rod went , it is most likely from a sealing/mating surface ......

[Dtrain412]

I appreciate the response. Thanks! I might just tear whole thing down and go through it with a fine tooth comb. Just frustrating, I’ve been working on this for the last 2 months in my spare time and making sure it was correct, but of course I didn’t start the project and apparently from what I just found out it was sitting like this for 6 years. But I’m not going to complain for only having a total of $1200 into it including the purchase of the bike.
Also any pointers on 2008 CRF450R, I purchased one with a thrown rod and was curious if there is any things I need to know going forward. I ordered the cases, cylinder, complete engine rebuild kit, balance shaft.

Again thanks in advance!

[JimDirt]

Yea , unfortunately , when you take on someone else's project , sometimes , you end up with a project of your own ....... , and with the 08 , I guess it depends on what you are wanting to know .... as far as the 08 itself goes , it is a great bike , with some of the best Honda has to offer , the engine was sought after for its performance , its suspension is one of the best Honda has done , and it was the first year with the steering dampener and 22mm triple clamps to aid in the handling , the same dampener that people are putting on KTM's ....

The only issues with any of the Honda engines is the Intake valve wear ....the Titanium intakes did not like dirt of any kind , and they were the source of many complaints , the solution to valve wear was to go to Stainless intakes and beryllium seats , if you are not a Pro , racing the bike , it is one of the best investments you can make on these engines , 250's included , I run stainless intakes in both my bikes

Keep the airbox clean , make sure dirt does not get past the filter ...... the nice thing about the older generation Honda's is the separate oil for engine and tranny , it keeps the engine side oil much cleaner , much longer than the other brands

No real downsides to the 08 , it is a great platform and one of Honda's shining achievements .....