Eric gorr, who runs the highly respected motorcyclemodification shop forward motion and its companion website, is dirt riders dr. Fourstroke motocross and offroad performance handbook by kevin cameron, eric gorr and ron hamp 2011, paperback at the best online prices at ebay. I also went with the low compression pump gas head mod to further reduce the off idle bark, and because i am too cheap to buy race gas. In the model tuning tips chapters of this book, all the head specs quoted have msv ratings. Review eric gorr rm300 suzuki 2 stroke thumpertalk. Transmission rebuilding clutch repair and rebuilding bigbore kits cam kits and valve timing and tuning tuning stock suspension suspension revalving and kits jetting and tuning carburetors tuning electronic fuel injection wheels, tires, and brakes chains and sprockets cooling systems. Max power 285 vs eric gorr 295 yamaha 2 stroke thumpertalk. I was really out of shape and the course was slick due to them being years old orv trails that had been. Big bore by eric gorr tech helprace shop motocross.
Build a factory race replica or maximize your stock motocross or offroad bike with expert techniques from tuner and columnist eric gorr. Mini motocross and pit bike performance handbook by eric gorr 2008, paperback at the best online prices at ebay. Fourstroke motocross and offroad performance handbook by. Pdf suspension tuning download full pdf book download. Second impression cylinder porting by eric gorr race. Telephonetexts 16308255645 mondaysaturday from 6am to 6pm cst eric gorr racing 650 oak park ave. Every year, dirt bike riders wasrc loads of money on rapend parts.
The difference between twostroke and fourstroke carbs. A lesser work would have surely passed into nostalgia heaven long ago. Motocross and offroad performance handbook by eric gorr, available at book depository with free delivery worldwide. Dirt and owner of forward motion, takes offroad enthusiasts through the paces of performance projects for their honda crfs.
Basic 2stroke engine tuning information joe hunt rc. First published in 1996, eric gorrs guide to maximizing stock motocross and offroad motorcycles and building factory race replicas has become the definitive work on the subject. You come back to the pits and your mechanic asks you if the highspeed rebound feels too fast. Forum main tech helprace shop big bore by eric gorr.
Motorbooks tuning guide to performance modifications. Top end assembly tips big bore kits 10 tips for rebuilding a twostroke top end top end faqs twostroke exhaust valves tips and tuning honda hpp kawasaki kips suzuki atev yamaha powervalve intro topend rebuilding is the most frequent and costly service routine on twostroke dirt bikes. First published in 1996, eric gorr s guide to maximizing stock motocross and offroad motorcycles and building factory race replicas has become the definitive work on the subject. So much myth and misinformation is associated with this complex machining and metal finishing process. Tuning suspension is explained in detail, describing everything from changing fork seals and replacing shock springs to revalving and adjusting the compression and rebound damping. Buy motocross and offroad performance handbook motorbooks workshop 3rd revised edition by gorr, eric isbn. The most common mistake is to choose the wrong combination of.
Fourstroke motocross and offroad performance handbook. Motorcross and offroad motorcycle performance handbook. A myriad of different aftermarket accessories is available for you to custom tune your bike to better suit your needs. Fourstroke motocross and offroad performance handbook this thorough howto manual helps the offroad motorcycle enthusiast get the most out of their machine.
As a rider on race day, you go out for your practice session and your suspension nearly kills you. Mini motocross and pit bike performance handbook by eric. Lastly, my 03 kx200wr 03 kx125 chassis with a 95 kdx200 motor has the eric gorr 223 kit yep, same jetting issues and the bike did not run any better than the stock kdx200. The honda highperformance fourstroke motorcycle is one of the most popular offroad motorcycles in the country. The book provides clearly detailed information on maintenance schedules, procedures, and the tools, materials, and space you ll need. Topend rebuilding is the most frequem and cmtiy service romine on rwostroke dirt bikes. Everyday low prices and free delivery on eligible orders.
Engine rebuilding transmission rebuilding clutch repair and rebuilding bigbore kits cam kits and valve timing and. Dirt and the author of motocross and offroad performance handbook, 3rd edition, also from mbi publishing company. Eric gorr porting motorized bicycle forum motored bikes. The people in the market to buy it are looking for information and the people in the market of selling it are hiding information on porting. In this book, widely known and highly respected tuner and journalist eric gorr, dirt riders dr. Eric gorr is the author of fourstroke motocross and offroad performance handbook 4. Eric gorr author of fourstroke motocross and offroad. Four stroke performance tuning download book pdf full. His prices for the work he does are great, near twice as much port work and proper chamfering. On page 51 gordon uses the term onepercenter, the term refers to an american motorcyclist association quote that 99% of motorcyclists were lawabiding. Note that my eric gorr 03 yz265wr exhibits the same issues and that head is going to ron black next week. Fourstroke engine rebuilding and tuning suspension setup and tuning carburettor jetting setup tips for latemodel motocross and offroad bikes from cover. Ive got the whole thing sitting here at home, 220 pages of how to do pretty. Eric gorr is famous for being an expert in 2 stroke posting.
First published in 1989 as tuning new generation engines, this bestselling book has been fully updated to include the latest developments in fourstroke engine technology in the era of pollution controls, unleaded and lowlead petrol, and electronic management systems. When the rod wears and produces more friction, the ileal melts the edges ollhe insert. Eric gorr 144 kits full engines i rode the thing for about 1 month and realized that i am just not ready for the power that the thing puts out. Eric told me it was all my fault, that i do not know anything about motorcyles, and that i should contact an attorney if i want my money back. He really talking abour a mixwre of fuel and oil if yoll rjchen rhe premix ratio 20. I have spoke with gorr a few times and he seemed very knowledgable and everyone seems to like him i wouldnt be afraid to send my stuff to him. This onestop reference covers everything from basic maintenance to performance modifications, including. Motocross and offroad performance handbook motorbooks. Going that extra mile, forward motion s eric gorr offers modelspecific suggestions for modifying the bikes to improve performance on and off the racetrack. Finally got out in a race with eric gorr tuning and did a very quick confirmation video. So, you could get less complicated to understand the perception and also significance. Dirt and the author of motocross and offroad performance handbook, 3rd edition, also from mbi publishing company more about eric gorr.
So i bought a cr 125 on cl and have been rehabbing it to get it in good shape for this coming season, once i am confident enough in my riding skills ill move up to the 450 again. He has served as a tuner for american and european offroad racing teams, and he resides near chicago, illinois. Tuning suspension is explained in detail, describing everything from changing fork seals and replacing shock springs to revalving and. The lalemodel yz125s use plaslic inserts to stuff the crankshaft and maximize throttle response. Video suspension tuning par eric gorr suspension tuning can be a mystery for both the rider and his mechanic. I now have a better understanding on how things should work and benefits me when tuning the kids bike. The process of cylinder porting is a funny paradox. Carb tuning page 2, by eric gorr the dirt bike, mx. This is a pretty good chapter and spells out the basics of. So, off comes the head and cylinder and away to eric gorrs forward motion for the 295cc bore job and mo betta wider smoother porting job.