Tonkaman's CRF450R build

[jentzschman]

Nice! I need to pick up one for my ride but thinking of a 3 gallon one.

 

[Tonkaman]

While riding in Caineville this weekend I managed to fry the clutch. It was weird because as soon as I felt it slipping I headed back toward camp but I was only able to make is a couple hundred yards. Maybe that's due to the recluse?
I think this big bore is going to make me go broke ha ha

 

[Tonkaman]

I got some replacement steel/friction plates and opened up the clutch for s quick swap. I immediately found what had gone wrong.... My own stupidity.

Last time I had it open I was rushing against the clock to make the annual St. George riding trip. While reassembling I ran out of locktite for the screws holding the Rekluse pressure plate on and just put it together without it. BAD IDEA!! All the screws came loose allowing the pressure plate to let pressure off the wave springs. When that happened the small wave spring rattled around enough it got mashed up, and turned into mulch inside the transmission gears. I spent an hour flushing metal shaving goop out of my transmission.

I put it back together today but only had a stiffer wave spring on hand. With that installed it engages at a higher RPM and WOW! The high stall and big bore combo really makes it feel like a torque monster. It was a blast on the road but I'm a bit scared to climb obstacles in Moab this weekend.



Moral of the story: buy locktite in bulk!!!

 

[Caleb]

Good info. I don't know if I've ever used locktite on those bolts. I'm about to start installing my Rekluse on my 501, I'll make sure to use some locktite. . Fwiw, on MX bikes, upgrading to a stiffer Bellevue washer is a very common upgrade with the rekluses. They even mention that in their install manual now and provide the part number to do it on the ktms.

 

[Tonkaman]

Well I broke the kickstart lever, AGAIN! Kicking the bike over is just so hard to do. During long days on the trail in Moab my legs struggled to get the bike started, and I realized I can't do it anymore. I need to change something to make it easier to start, and to save on kickstart lever replacements. I don't want to buy a new piston so I'm looking at other options.

Will high octane fuel help it to start easier? It doesn't help with the difficult kick, but if it fires right up it won't wear me out.

How much could I drop the compression ratio with a thicker head gasket?

Should I have a machine shop make me a custom length decompressor pin? This seems like a great solution, but it's trial and error for the perfect length. No clue how much labor it would take to figure out.

The bike is a dream machine as long as it's running. Too bad I dread shutting the bike off for fear of kicking it over again.

 

[anderson750]

Sell it and buy a 300. I know of one that was lightly ridden on Saturdays that is going to be for sale in about a month. But in all seriousness, this is what comes with building something with high performance. They will be finicky and bring new elements of maintenance and problems. I am of no use in solving this problem, so you can just post up a big old if you like.

 

[Gravy]

Better get a new one quick so you can race this weekend!

 

[Tonkaman]

Sell it and buy a 300. I know of one that was lightly ridden on Saturdays that is going to be for sale in about a month. But in all seriousness, this is what comes with building something with high performance. They will be finicky and bring new elements of maintenance and problems. I am of no use in solving this problem, so you can just post up a big old if you like.

Honestly I have every intention to buy a new bike as soon as I can afford one. This bike will likely get sold to pay for the new one, but hopefully just turned into my sand machine. I've never ridden a 300 so I won't discount it even though it's a 2 stroke

 

[Tonkaman]

Better get a new one quick so you can race this weekend!

I've confirmed my plans for the sand dunes this weekend or else I would come give it a shot. This will give me a chance to mess with a few settings on the bike also

 

[Jared]

A thicker head gasket would help, and that's what I was about to suggest before you mentioned it. It's also cheap, and a relatively easy solution. Back in my TRX250R days, we'd run a CR or ATC head gasket which was I believe .010" thinner than the stock FourTrax gasket. This allegedly raised the compression about 10psi. It was enough to notice a slightly harder kick start, and enough to make it really start pinging without premium fuel.

My '04 TRX450R had a Stage 3 Hotcam and a Venom (?) 13.5:1 piston in it and it really wasn't hard to kick over at all. I'd just find the compression stroke slowly, then give it a hard kick and away it would go. I don't know if that setup retained the auto decompression setup or not. Getting your decompressor to work is really going to be the long term fix, I'm sure. The guys over at trx450r.org would probably know the answer for the specs on your pin. The quad has the same motor as the bike starting in 2006, I believe.

Good luck!
Jared

 

[Rot Box]

Well I broke the kickstart lever, AGAIN!

Crap really? Sorry to hear :sick: Have you tried the ol' find TDC knack? For example my old WR426F (no auto decomp cam) was impossible to start without doing this routine: Slowly kick it over until you find TDC, then kick slowly past it no more than a 1/4 inch, then hammer down on the kicker. I had to do this every--single--time--no--exceptions. It didn't matter how strong you were it would NOT physically kick over without doing this. Once I finally got in the habit of doing that every time it was easy to kick and would start great although the whole process was kind of annoying. I'll bet that would help if you haven't already been doing it. Hope this helps.

 

[glockman]

Get weaker quads like a normal human and you won't break metal parts with your leg! Or do the TDC thing Rot Box mentioned. I also suffered a 426 and agree there if this method worked on that bike, it should work on any bike with auto decompression.

 

[Tonkaman]

I was finding TDC for a while and it never seemed to help so I gave up on it.

Another issue I've noticed that may be related is re-starting after it's been tipped. This bike punishes me for tipping it over. No other bike takes as much effort to clear out a flooded engine as this one, not by a long shot! Any ideas why?

 

[Tonkaman]

I just rode the sand dunes for two days and fell in love with this bike again! This bike is scary and I love it. The sand had been whipped up like powdered sugar from the recent wind storms making quicksand pits to bury the bikes in. With the power of this monster I could ride a gear high and when trouble happened it would rip though the RPMs with such ease that I could climb out if the deepest sand traps. The Evans coolant really showed its value out there. Typically my bike would boil over pushing it that hard out in the sand, but it never even got hot. My buddy with the same bike was running engine ice and he was boiling over.

As an update to my earlier questions I decided to take the easiest approach and try race gas. I ended up buying Sunco 260GT which is 100 octane that is oxygenated. I decided not to dilute the fuel and just run it straight to keep the results more scientific. It fired up on the very first kick!!!!! That never happens! Not even when the bike was new it would start first kick, right off of the truck! Needless to say this was exciting news. Over the coarse of the weekend my bike started first kick every single time, even after laying it down once. Happiness coursed through my veins every time I heard her fire so easily.

Now the question remains, was it the high octane, oxygenated fuel, or the elevation/temps that made it run so perfect? I'm going to try a test run locally soon with the same fuel to rule out the elevation/temp differences. If that has good results then I'll get some high octane fuel that is not oxygenated and see what happens.

 

[Gravy]

Sounds like bumping down the compression would make it more manageable.
Higher octane means it resists pre ignition better. Could you have some pre ignition on the slow (relative to running speed) Kickstart ignition stroke? That might explain the kickback, (provided the decompression cam is working).
Perhaps we could pull the valve cover and watch if the decompression pin is working correctly.

 

[Tonkaman]

The pin is definitely working correctly. According to Lindsay machine the pin needs to be longer to allow for more decompression. Dropping the compression ratio is still an option but if fuel works that is just so much easier.

The strange thing is lots of guys are running 13.5:1 on pump 91 without issue. I also never had knocks, pings, or backfires associated with pre-ignition.

 

[Tonkaman]

A few months back I bought a brake upgrade kit with oversized rotor, lines, pads, caliper rebuild, and master cylinder rebuild parts. Well I've just been putting off ride after rude like the procrastinator I am, till finally I had no brakes. I was in no rush to do the job until Russ posts up about a 5MOH trip then I suddenly felt motivated. Friday evening I spent a few hours rebuilding and swapping out components leaving the brake fluid for last. About 7 o'clock I hooked up a vacuum bleeder, filled the reservoir and started bleeding. Those stupid brakes just would not build pressure! After about 3 hours of cussing Jeeper showed up to help me out and show me how it's done. Many failed attempts later we decided to go buy a syringe and back flow the fluid, so 11:30 pm we drive down to Walmart. 1:30 am we finally got a firm rear brake and a half squishy front, but due to the cold and sleep loss we called it good enough. By the time I loaded my bike, gear, and got clean I hit the sack right about 3:00 am Saturday morning only to wake up before 5:00. This would end up being one of the dumbest decisions I've made...


6:25am Saturday morning we meet up with the guys and hit the road south. We all have a good laugh about how little sleep we got and how much we waited till the last minute to get ready. After a 3.5 hour drive we were anxious to hit the trail and conquer 5MOH. The trail starts off from the lot as more of a whooped out desert two track and is actually the red trail. It's not for about 4 miles that the actual 5MOH trail head splits from the red trail and herds you toward some of the nastiest rock obstacles the country has to offer. 1.5 miles and lots of rocks later I had a catastrophic failure. Poof! This massive white cloud started billowing out from under the bike, spreading so quickly I had trouble finding the cause. Fire!! I yelled out. Fire was my first thought and worst fear especially since I had about 3 gallons of gas sitting in the tank. Luckily after a few seconds I realized it was just a white cloud of boiling coolant and oil mixed together turning it bright white.
https://youtu.be/f0litxjZoSQ

Stratton, Brian and I stayed with the bike while the rest of the group continued on the trail. We tied a rope around each fork tube and made loop handles at the other end. This gave two good points to pull the bike while a third person pushed on the handlebars to navigate the rocks. I can't believe how well this system worked out! Don't get me wrong, I was hurting bad! I was so low on sleep and jacked up on red-bull that my body was having a hard time coping with all this hard work. Luckily the guys were able and willing to pick up my slack whenever needed and muscled that bike back to the red trail. Once the trail was good enough we towed the bike out foot peg to foot peg nice and slow.

In the end I actually had a great trip. I feel bad that my problem effected other people's day, but we had a ton of fun just talking and walking. Everyone that came was very helpful and generous, such a good group of guys that I hope to share the trail with for years to come.

 

[Tonkaman]

I started disassembling my bike tonight to asses the damage and more importantly prep to sell. I suspect I will find a blown head gasket, but hopefully the damage ends there. More to come as I open it up

 

[Tonkaman]

I spent some more time disassembling tonight. I decided to strip it down bare so I can polish up really good for the sale. I think I'll paint the worn engine cases and polish the aluminum frame.
Luckily I still have a complete gasket set so it won't cost me anything to pull it apart.

-Any idea why the valves and plug are golden brown?
-what's the green residue in my carb? Is it from the race fuel?
-Can anyone recommend good paint for the engine covers and triple clamps?

 

[jeeper]

WOW!! that's some serious progress!!!
Any sign of what might have been the failure?