Jun 10, - Dirt Bike Tech Two-Stroke Seizure: Dirtbike: Seizure is an easy thing to A look at two-stroke engine seizure and why your piston can lock up solid The common causes of this problem are broken needle bearings from If it doesn't seize, you ride it the rest of the fall, and then put it away for the winter.
What was the cause of the damage? We will help you to correctly diagnose damage in day-to-day repair shop activities and prevent expensive consequential damage. What steps plaines bike I need to take before installing new piston rings? What do I need to watch out for when fitting the piston how to fix a seized dirt bike engine Our step-by-step guide provides answers to how to fix a seized dirt bike engine and many other questions What do I need to watch out for when fitting pistons?
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The history of motocross is littered with the tales of these terrible bikes. When I set out to document these engineering tragedies I laid down a few ground rules. I decided to limit my selections to motocross racing machines only the Honda Fat Cat lives to fight another day! I also wanted to be fair and only compare the craigslist dc bikes to bikes from their own era. This really was the Wild West in terms of design and the manufactures tried all kinds of crazy ideas on the bikes.
This incredible period of technological innovation how to fix a seized dirt bike engine birth to some of the most iconic machines ever to lay rubber to dirt. It also produced some of the biggest turds ever to foul a plug.
This is their story. The Suzuki TM Cyclone. At number one with a bullet, we have without a doubt one of the most terrible and infamous motorcycles ever produced, the Esized TM Cyclone. Those forty horses were not of the easy to use varietyhowever.
The power was basically a light switch with an all or nothing delivery. Compounding the abrupt power was a crude and unreliable ignition system that would how to fix a seized dirt bike engine the bike to run erratically at times and greet the rider with a sudden and unexpected burst of power.
Sometimes the power would kick in at rpm, sometimes it would kick in at rpm and sometimes it would just sputter and cough and you thought the KXF was trick with its variable ignition programs, Suzuki had it in 71! Unfortunately for the unsuspecting TM owner the fun did not stop there. The forks appeared to use internals long beach bike ride from a Bic pen and shocks would last about ten minutes before trying to eject the rider into orbit.
The frame on the Cyclone did not help matters as it flexed so badly it would bind up under a load and then snap back like a spring when the rider rolled off the throttle. This usually resulted in the unsuspecting TM rider launching himself into the weeds…or how to fix a seized dirt bike engine. The motor became easier to manage and the handling was improved a small bit.
By that time however the die had been cast and the TM Cyclone was thoroughly entrenched in the minds of the motocross community as a dangerous and scary machine.
In an gike filled with unreliable, crude, and generally crappy motorcycles, the TM was the crappiest of them all. Yamaha has had a long, checkered past in the open class.
Dort open class offerings have run the gambit from awesome to gruesome over the years. For every fantastic YZ we would have an equally dismal YZ to counterpoint it. For Yamaha the open class has been a forty-year roller-coaster ride specialized full suspension bikes success and failure. Since cheap dirt bike neck brace roller-coaster ride must start at the bottom it is appropriate that we start right here, with the SC Scrambler.
Weighing in at a rather porky lbs, dift SC featured an air-cooled cc reed valve two-stroke single mated to a four-speed transmission. Handling the suspension duties were a pair of remote reservoir rear shocks and a set of inline axle front forks offering a good for the time four inches of suspension travel.
If there was one word that best described the SC it would have to be grim. Pretty much everything about this xirt was terrible. The big cc single was virtually impossible to jet correctly. It would sputter, cough how to fix a seized dirt bike engine stall fuji bikes online. The throttle response was notoriously terrible and one tester at the time described it as having less low-end power than a good running The SC delivered all of its considerable forty horsepower in one big explosive midrange rush that sent the front end skyward before quickly tapering off into a non-existent top-end.
Adding to the motor misery was a propensity to overheat and seize at regular intervals Yamaha should have offered pistons in six packs for convenience. The SC suffered from envine weight balance resulting how to fix a seized dirt bike engine an overly light front end. As a result the bike wanted to wheelie how to fix a seized dirt bike engine and would wash out the front end in diry. At speed it would shake its head violently enough to rip the bars from your hands and swap side to side as if it had vix hinge uow the middle.
The forks were terrible even by standards and beat the rider to death over every bump. The high tech looking remote reservoir shocks were just as bad and would fade after 5 minutes bounding up and xeized like a pair of pogo sticks. A contemporary Cycle magazine test put it best when describing the SC They commented that Yamaha got all the minor things right on the SC but totally missed the boat on the big important ones.
By contrast the European bikes were all fragile and finicky but handled and performed light years ahead of the Free bike catalog.
What we bkke here is one of the most anticipated motorcycles ever produced, the CRR. The hype machine was in full swing and the buying public was waiting with checkbooks ready to plunk down their hard earned cash on the fastest, nastiest ground pounder ever to throw a roost. What they got instead was one of the xirt confused how to fix a seized dirt bike engine disappointing machines ever to hit the showroom floor. Honda had begun producing lightweight two-stroke race bikes in with their revolutionary CRM.
The CRM helped usher in a whole new era of high performance Japanese race bikes in the seventies. Honda, Bike trim, Kawasaki and Suzuki made quick work of their European counterparts, gobbling up market shares in mighty chunks. By the end of the decade the Japanese had a near stranglehold on the American motocross market. Throughout this explosive growth period Honda homemade bike light resisted building a true Open class race bike.
They had stuck to producing cc and cc machines only. This is noteworthy because motocross in the seventies was very different than it is today.
By not producing an Open class bike Honda was left with a huge hole in its portfolio. It was in this climate of completely unrealistic expectation that fxi CRR made its debut.
When the production CRR finally made its appearance in the fall of ,it certainly looked the part of a serious race machine with its how to fix a seized dirt bike engine bodywork sfized screaming red paint job. Honda called their system Pro-Link and it is actually very similar in design to what we still use today. Handling the suspension duties on the 81 R was the odd combination of a Showa rear shock and 41mm Kayaba front forks.
I can only assume the ridiculous shape was an attempt to get more air to the seizeed. Whatever the reasoning behind it, Honda should have never let it see the light of day. It got compared to rear shocks mountain bikes from a hangnail to a snow shovel and became something of a symbol for the inept performance of the much-maligned R. The heart of any race machine how to fix a seized dirt bike engine its motor and that is really where Honda shot itself in the foot.
The Engjne was actually not a at all but rather a smallish Instead of crafting a purpose build too class motor Honda had basically bored and stroked their existing CR motor out to cc to turn it into a big bore.
To make matters worse Honda made the dubious decision to install a four-speed transmission in the bike instead of the more versatile five-speed.
The result was a total disaster. The CRR ran like a big with a very narrow spread of power and very light flywheel.
It would explode suddenly in an uncontrollable rush of wheel spin and just as suddenly fall flat on its face. The powerband was razor thin and when combined with the hopelessly spaced four speed gearbox the bike was virtually impossible to ride. The peaky cc motor was easy to stall and required a lot of clutch abuse to overcome the oddly spaced transmission.
Unfortunately the clutch was how to fix a seized dirt bike engine up to the job. The clutch would grab, lurch and eventually start slipping huffy women bike a two-speed Powerglide.
The clutch would decide it was time to go whether you liked it or not.
The bike would headshake at speed like a wet dog how to fix a seized dirt bike engine out of ditt bath. The Showa shock was sized soft initially, and then it would hammer your spine when bike ads rising rate linkage kicked in. The mismatched Kayaba forks would bottom out over anything bigger than a candy bar. About the only thing the 81 CRR did well was turn.
If you could harness the rest of the bike it would carve a nice inside line. They say you only get one chance to make a first impression, but thankfully for Honda the buying public forgave them for the tragedy of the CRR. Best of all, someone had bike blue ridge parkway sense to drop kick that ridiculous number plate.
how to fix a seized dirt bike engine That alone is worth two horsepower in my book. There is almost a magic to making a big bike work. A chassis that works like a dream hoa a 30hp will become american made mini bikes unruly beast when mated to a 60hp big bore.
It is a true test of engineering know-how to turn a cc brute into manageable machine. In the early eighties it was a test a lot of the Japanese manufactures were failing miserably. In Kawasaki had introduced an all-new big bore to compete with the all-powerful Maico Open bikes. The big German was THE bike to own in the Open class boke the time, combining a sweet tractor like power delivery with excellent chassis dynamics.
The KX was overweight, less powerful, poorer handling and incredibly, more fragile than the notoriously finicky German.
This brings us to the subject at hand. You would perhaps be right in thinking that if a company takes san francisco bike races year off to regroup uow comes out with an all new model, it should be better than the one that had caused them to quit in hlw first place. Well, in this case you would be wrong.
This bike was bad, so bad in fact none of the magazines could even test it in stock form. The 83 KX had a motor so poorly designed that it would blow itself to pieces in the matter of a few laps.
The big Kawasaki was saddled with a terminal case of the knocks and if left unchecked, it would how to fix a seized dirt bike engine beat how to fix a seized dirt bike engine to death in short order. Once the motor got a little hot it would start rattling like it had a box of marbles loose inside it. If you ignored the death rattle, the next sound you would hear was a very expensive z, as big pieces of aluminum became little pieces of aluminum.
This baby was dit grenade with the pin pulled. Big bore two-strokes are a temperamental bunch by nature. Something about that huge piston makes the monster motors much more difficult to set up. In the seventies and eighties virtually all the enngine struggled to get these big bikes to run correctly. Yamaha in fact spent the entire decade of the eighties trying to get their YZ to run dirt bike led light kit only to finally give up and quit the class altogether.
Knocking occurs when the pressures and temperature in the cylinder reach the dort where the fuel charge will spontaneously ignite. Because this ignition occurs out of time with the normal combustion cycle, severe cases can destroy an engine very quickly. The only way mendocino bike rides get the KX to run properly was to send out the motor to be reworked.
If left stock, it was hopeless.
Riders tried everything from going richer on the jetting to altering the ssized timing to get the big green pig to run right, but nothing worked. While the KX was still in one piece the motor was a hard beast how to fix a seized dirt bike engine ride. It blubbered off idle and then exploded violently as the revs climbed. When it hit the powerband it was new belgium bike for sale to hold on tight and make sure you were pointed in the right direction.
This motor was the very definition of violent. As engjne typical of most big bores of this era, there was very little top end pull after the monster midrange. If you santa cruz bikes chameleon out the big KX all you were greeted with was more death rattle and worse vibration than a Harley with how to fix a seized dirt bike engine motor mounts.
Check fuel line to make sure it does not leak. If it leaks, replace with new line. When replacing, make sure hose clamps from petcock to filter, and filter to carb are in place and sufficiently tight. Check the fuel filter. If gas doesn't flow through or flows slowlytry rinsing it out.
You may use carb cleaner sprayed in the reverse direction of the fuel flow to clean most filters. Be careful and wear eye protection! If the filter can not be flushed, replace with a new one.
If fuel will not flow through it with the valve turned "on", "res" or "pri"remove it from the tank. Clean it, and any filter that might be attached, thoroughly with carb cleaner. Make sure fuel will run through it, and reinstall it on the tank. Be careful not to damage any gaskets during this process. On to the Carb!
Most motorcycle carbs are fairly simple. Don't be intimidated. My son enngine a carb-whiz by age It takes a bit of experience to tune them properly, but not too much just to get them "almost" right. Gently remove the carb from the bike. Take care not to damage the rubber intake boot. Remove the bowl. Clean hod needed. Remove the float. Carefully clean both the opening and how to fix a seized dirt bike engine needle how to fix a seized dirt bike engine.
Clean any exposed jets both inside the bowl,on the body of the carb, and in the throat of the carb. Remove the cap. Clean all exposed parts both gmc denali bike review venturi and the exposed inner parts of the carb body.
Reverse ifx of disassembly. Carefully reinstall carb, one again taking care not to damage the intake boot. Check out the instructable Star stasterisk did on cleaning carbs.
She did a great job, and under good circumstances, carbs can be cleaned while still on the bike. Pull the plug. Check it's condition.
Worn, sooty, fouled, or damaged plugs can be an indicator of other engine problems. You may clean an old plug. A wire brush, carb cleaner, and compressed bikke do a good job.
A lit match held just under the electrode will usually help a fouled how to fix a seized dirt bike engine. If you use a match or lighter on your plug, keep it away from fuel and carb cleaner! If you can't save the old plug, replace it with a new one.
Make sure it is the correct one for your machine! Gap your plug to manufacturers specs. Make sure the plug will fire. This is really a test of your entire ignition system. If everything is right, you'll see the plug lake champlain bike tour a fat blue spark.
If there's no spark, work backwards from the plug through the xirt system, until you find a short, a bad connection, or a non functioning component. Often on old bikes, the points need to be cleaned. I'd try it with a business card first, then spray-on electrical-contact cleaner, then emory not sand paper.
When your electric problems are solved, it's all downhill from there. While you have the plug out, it's a good time to check for compression. You can find the pump by tracing the enhine most often it is easily accessible for a quick check.
You have to actually look.
On newer, emissions-controlled motorcycles, I see a lot of cases where the bike runs out of power and stalls.
Once pulled over, they restart OK, then stall again 3 miles later. In these cases, try running with the gas cap seizdd Hopefully this will stop you from being jammed up by something simple, and it may just get you to the nearest gas station.
For carburetors that suddenly show signs of being in a rich condition, gently whacking the bottom of the carbs to make sure the floats tiny little pieces that control gas flow like the rubber piece in the back of your toilet are free. Also check that the choke cable works.
After that, solving a rich condition gets more involved — such as checking the spark plug gap or fuel bowl levels. A key clue is that the issue gets better as the bike warms up. Extremely lean motors can how to fix a seized dirt bike engine stall out completely when given some light throttle. First, start simple and look for a loose or open vacuum hose. If it is, lean running is the No. For EFI, much of the old-fashioned carburetor how to fix a seized dirt bike engine craigslist bikes nj done away with.
Just be sure the pressure sensor on the airbox is connected right and has vacuum, and that nothing is unplugged. A simple web search reveals both how to activate this feature and translate most codes, as well as how to resolve the issues. A no-start can seem like something impossible to fix except in the shop, but there are many problems that can be resolved with some detective work.
First, ensure the battery is good and that the engine turns over. If your battery is OK, but nothing happens when you hit start there are a few things to check.
News:Mar 28, - (for the list of the bikes that changed motocross, click HERE) No matter what brand you select or what type of motor you choose, you are . Adding to the motor misery was a propensity to overheat and seize at regular .. For the season Honda's goal was to fix the minor complaints people had with.
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