Blew the motor

So, mid wheelie in 2nd, I was trying to get the lead on two friends on sport bikes the bottom end let go. It was a power wheelie and I was about 3/4 throttle about to roll off (or go over) and there was a hell of a bang and the motor locked up. It was so sudden it skidded the rear tire mid-wheelie, tossed me onto the front tire for a bit then landed the rear again. The tire skid marks tell the story....skid...space...then more skid which varies in width as the suspension oscillated. It was actually exciting...then sad...

So...what to do.

Obviously rebuild. The cases are cracked at the front, where the counterbalancer lives. I can see inside a bit, think it's the right side bearing journal but until I get it apart I'm not sure. it looks pitted with perfectly round holes, kinda like and AERO Chocolate bar.

Yes, I have photos and will post them when I get a minute.

Now, what parts to collect is my question and the point of this thread. I'd go for the HRC kit but... As that is not available my thought is a slight bump in power without losing the bottom end torque. From my limited research I have in mind:

11:1 piston
Stage 1 cam
Slight porting to smooth flow.

I will be sending the head out, not screwing it up myself.

So if anyone would like to make an informed suggestion I'd appreciate it, and yes I expect to get some verbal bashing...Mauser...

Thanks Guys,

hi icelander, sorry to hear of the explosion!.., its a worry when you see holes, it may be advisable to obtain a less damaged bottom end if the conrod has been a wrecking ball inside those cases, surely it was giving a few signs prior ...?,anyway now the thing is in need of some careful diagnosis and a chunk of cash to remedy, i highly recommend the upgrade parts, also replace the std carb if funds permit- unless you still have the std exhaust , that should be the first thing to toss on the scrap heap, stage 1 upgrades really liven the xrr up and dont put undue strain on std bottom ends, enjoy the process

Spotted this thread on Facebook...I think, gutted about your motor I brought a set of cases the other week as a "just in case" only cost £80 delivered so happy to sit them in the loft lol....
I would build a stock motor myself as the bike runs great in stock form, but if you feel the need for more power then go for it

I had some time to get the motor out of the frame, snapped a few photos and tried uploading them to Photobucket to embed them in this post... Aparently Photobucket is crap now, so slow it's unusable...it's been a few years since I've posted anything. Does anyone know a good photo hosting site to use? The motor is getting dissassembled Friday and I was going to share with the other children.


To answer Temporary Kiwi's question, there was no indication at all that a catastrophic failure was imminent. I'm a truck mechanic and am a bit obsessive about maintenance, especially on my stuff. I cut open the oil filter after each change (1000km or 625mi), and look for something not liking something else inside the motor. I'd just done an oil change the day before and rode maybe 150km or 93mi. Bike was running as it normally does. I'd explain what I've found so far but I think the photos are worth waiting for.

If you're on Instagram (the only "social crap" I'm a member of), you can see them there. I'm Icelander71 or just search for XR650R...

Soon as I can find a photo hosting site that lets me embed and I learn how to use it I'll post photos here

It was motor disassembly day today. I've got a bunch of photos, I'll post them as soon as I find a decent photo hosting site.

So, what made the con-rod punch through the counterbalancer shaft and blast two holes in the front of the case? Well, it was not caused by the con-rod failing. I'd first thought it was, then found half a roller bearing for the con-rod. Yep, HALF. one roller split perfectly in half down it's length.

So, a bearing split in two, one of the two half-round pieces ended up with is broke flat side against the crank journal, the next bearing following runs into and up over it and apparently you can't stack a bearing and a half in these motors. it actually broke the lower half of the con-rod big end off almost perfectly symmetrical. It kinda looks like an automotive style end on the rod, just no bolt holes or bearing shells. The now loose con-rod was free to flap around and do whatever it liked. Evidently it didn't like the counterbalancer very much.

It's time to start looking for parts... I'm looking for a new cam, on the XR's Only site they have two available. The Hot Cams Stage 1, and the HRC Copy Camshaft. Does anyone know about these cams and the differences?

Yo Icepick

those cams are 'hotter' than the std one, surely you know that bit?
If that's what you want then fine, and know XRsOnly found a genuine HRCcam for me (exceedingly rare mind!).
In my opinion this (or the copy-cam) is the way to go as few will be able to improve on Honda's cam, simply because they are 4stroke gurus..... oh wait, Yamaha is too, but they don't make cams for this bike
Oh, I've not mounted it yet, can't tell you on the performance but put it this way: I've never ever read about someone who complained about this cam!

Thanks for the reply BuRP, I do know the cams are a little hotter, just wasn't sure which was the better choice. This is definitely not a limitless budget build but I want to put the best parts into the bike I can. I don't want to do this again soon so I'm going to try to build the best motor I can. I'll give XR's a call and see what they can find. So far the plan is new crank, counterbalancer, cam, cam chain and guides, piston and rings, Falicon rod kit, new oil pump rotors and cover, new waterpump, new stator, new bearings and seals, new valves and seals into the head, which is getting a mild port/polish (pretty rough casting in the intake and there is quite the step between the head and the valve seats). Ebay the cases and a flywheel. I'm sure there will be more... I believe this will provide a small but noticeable performance improvement without sacrificing the reliability. I don't know what use the bike saw before I got it, I know it's been on the track, and flogged hard. I ride it hard myself. The fact that the motor looks as good as it does inside with almost no wear makes me believe that a slightly modded motor would not affect the longevity.

New piston?
I'd get a higher-compression one, 10.5 I have ready myself.
I know there's a few 11:1 also but this ratio proves, in my CRF230, to 'ping' when the going gets really tough in hot weather, so I'm glad I got a notch less for my pig.
Hey, by all means try if you want the maximum...
The HRC-Copy cam I'd say is best-tailored for this engine, my hunch is the 'StageX' is just a generec profile - which may be good, dunno but as said I've bought the Honda cam.
Have fun building!

I've managed to compile a list of parts and prices from one of the main on-line suppliers which I'll enter into a spreadsheet and then be able to easily browse other sites and compare, as well as seeing what my local Honda dealership can do. The dealership treats me well so it will be interesting to see the difference. With the Canadian and US dollar where they are plus duty it might be close. If there is a place that I can purchase parts cheaply I'd love to know about it.

I dropped the crank off a shop called Performance Improvements, I was given their name as one of the places that can split a crank and install a new rod. When I explained what had happened to my motor they suggested I bring my crank by to determine if it is actually damaged. When I arrived they gave it a visual examination and saw no indication that it could not be used, as I was installing an aftermarket new rod and pin. I'll know tomorrow if the crank specs out fine, if so they can get the Falicon rod and press it in.

I'm also going to go with the Wossner 11 to 1, HRC copy, and a mild porting, new valves and springs. Speaking of valve springs, does anyone know if there is any truth to the comments about Kibblewhite valve springs failing or causing other components to fail? I don't want to make a negative decision about a manufacturer based on internet hype. If so is there a better option?

So a quick update. Cycle Improvements tested the crank and it's fine, I'm having them install a Falicon rod kit. Received engine cases from the Ebay Easter Bunny that look amazing with no damaged threads in any holes. Have to order a cylinder, balancer, cam and piston. Couple months and it'll be ready I hope.

First thing I hear about Kibblewhite springs not being good, got a set lying in wait myself.
Keep us informed please about this?

nothing wrong with them, they are quality stuff, used em in all my mtrs, revved to 9300rpm no problems, cant say that about the persons who may or may not know how to install them though- alot of muppets around, bewary

temporary kiwi wrote:cant say that about the persons who may or may not know how to install them though- alot of muppets around

Aww come on now, how difficult can that be?
A cutting torch & gloves: heat them up until red, then install them with a big hammer and Bob's your uncle - easy peasy Bru!





Disclaimer: IF ANYONE BELIEVES THE ABOVE THEN GO FORTH, DO IT AND FORGET TO MULTIPLY PLEASE, AND DO NOT BLAME ME BECAUSE IT IS A JOKE!

Sorry for the delay in replying...kinda busy.

The process is ongoing with the XR, I received the crank back with the Falicon rod and it looks awesome. Bought a counter balancer and cylinder from Ebay, the balancer looks very good, the cylinder looks like it's new with no marks at all on the outside and the crosshatching is still very prominent without a mark inside the cylinder. I got lucky with both the previously mentioned cases and this cylinder. Got a free stock cam and stock piston with the counter balancer, not sure what I'll do with them. If someone needs something we can discuss that through PM. (Just be patient I'm not on here often but will respond)

Except for the camshaft and piston, which I'll get to in a minute, every other item was ordered from my local Honda dealership. They should be in soon and then I'll decide on which stator to go with as that is still up in the air...I'm open to suggestions, my stator was damaged so rewinding it is not an option unless I stumble across an inexpensive used stock one. I have a friend who with be doing the electrical for me (I paid for his ticket to the Toronto Supercross so he's rewiring the XR) He's an electrical engineer and is familiar with rewinding stators. He'll be looking to make a wiring harness similar to the ones that used to be available from Vancouver Supermoto (VSM), which they called a "Warness". Using my old broken cases he'd like to set up a jig to be able to do full testing on a stator and regulator/rectifier to do bench testing. The electrical schematic is done he's just waiting for a stator to make the harness connectors match.

I wanted a HRC Copy Cam, however after much research I will not take the chance of dealing with XR's Only. Yes, I know this is possibly a contentious subject but I have done my research and I am not willing to deal with them. If you disagree do your own research, I did mine. I looked for another supplier of the HRC Copy but was unable to find one. If there is another supplier I'd appreciate learning about it. So I'm left with getting a Hot Cams stage 2. An 11:1 Wosner piston will be coming from a local distributor.

Ok, about the Kibblewhite springs. They are apparently hit and miss, the original reason why I asked is that I have a close friend who had a DRZ400SM and a K.W. spring broke. The motor was assembled by a well respected motorcycle shop. The shop dealt with the result without issue, however my friend who actually works in sales at a dealership did some research when the valve spring broke and found that indeed they are known to fail even when installed properly by knowledgeable persons. The bike was sold immediately upon receiving it back from repair. I wanted to know if the XR650R crowd had similar experiences but have not had anyone provide first-hand information that would indicate that there are any issues. As I'm now going to use a Stage 2 cam, stock springs are just fine so it has become a moot point as new stock rockers and springs are going in. While I don't wish engine failures on anyone or any type of bike, lets hope it's a DRZ application issue and not a KibbleWhite issue, or at the very least an XR650R issue!

I think a couple months and the XR will be together...I'll keep updating as things progress and report any issues I learn of.

Yo Ice,

Pls allow me to chirp in here, XRsOnly-wise.
Yeah, I also read about their bad rep, one can find many a disgruntled comment out there.
But I am in South Africa where this bike was never sold, and wanted a number of things unobtainable locally.... which are all listed on their website, so I thought oh fork, let me dive in at the deep end and ordered a few.
The first batch came without quibble, so that was a good start.
Good stuff too I should add.
Then I wanted more, also a camshaft this time.
So I sent off an email, asking what the chances were to get hold of a real genuine HRC cam - which I wanted because it has the decomp system (which the copy-cam has not, pls know it).
After quite a while (forgot, say almost 2 weeks?) I got a short curt reply that they could get me one (1, rare as hen's teeth) but I had to wait quite a bit, I think they mentioned more than 4 weeks.
I replied that I was not in a hurry and, to save cost on shipping told them to hold all I ordered until it came in.
Then waited, didn't even get a reply in fact.....
I waited for over 2 months - and just as I was going to send a mail like "hellooo, anybody out there?" I got a mail that the cam had come in, I needed to pay and they would send the lot.
I did and it got here!
I may be an oddball but I consider that helpful service, after all I asked for something off their product list and rare as shite - which they got me!

Now, the bottom line here is, and this seems to coincide with all the negative comments I've read about them, is that their stuff is good & they do deliver - however they suck in their email-correspondence!
No doubt they're inundated with gazillions of mails which, bear with me for a mo, you yankees expect to be answered with lightning speed, immediately, simply because this seems to be the to-do standard there!
Not here, local service levels are beyond comparison if at all detectable (it IS getting better the last few years though), so I wasn't too fussed when they did not reply for months on end.
But, a big BUT, you guys can phone them: it's a local call, no doubt it'll be answered and then one can talk through the various queries one may have - lots better than firing off a mail and hope for the best!

So yes, of course you may think of them what you like..... but I may too, and this is after I've dealt with them a few times.
Worse, I'll order from them again: they have it, I don't think they're overpriced, and they most certainly do deliver!
Can I ask for more?
Well, if you (XRsOnly) read here, if I were you I'd get someone to answer emails - it will keep difficult/hasty customers happier whilst it could/would keep bad comments at bay I reckon.


Chris in SA (a member who reads here), you had my HRC cam copied I believe?
If so you know if you're happy with it, and if so I suggest you tell Ice what you did - or perhaps you can refer him to whoever you bought your cam from?
Could only help him...