Four-Stroke

im new to trials and i want to get a 4t bike, but not sure which trials bikes are 4t? will be happy with any replies. thanks bleddyn

Hi 1st off this isn't on a trials bike but I do compete on a GasGas and trials guys seem to be a bit more clued in on engines than the general biking fraternity so heres my problem. I've just replaced the engine on my sons pitbike with a brand new unit re-using the old carb and exhaust, engine is the same type but not same make so may have differnet spec cams, valves etc. The old engine ran fine with this carb and the carb is clean. When you blip the throttle wide open from tickover it bogs down and trys to stall but if you open the throttle a bit more gentley it'll rev quite nicely. Riding wise it pulls fine as you don't really go from zero to full open but the plug …

Hi all. I am trying to build a trials bike using an engine from a 1978 Kawasaki KL 250. This build was inspired by some fantastic pictures posted on this site by Booma.... My problem is, i am not using the same frame he used and am having trouble getting the carb to fit in the frame. My question is... Can i lengthen the inlet manifold? If i can lengthen the tube from the carb to the head by about 30mm it will make fitting far far easier. The problem i have is, i have no idea what effect this will have on the mixture and running of the engine? If anyone has any knowledge of this subject? I would greatly appreciate the help. Many thanks.

does anyone know much about these bikes as ive just brought one are spares available im going to twin shock convert the bike but leave the mono shock on as well as im a fat ******* ive ordered a 9 tooth front sprocket for a tlr 250 twin shock hope it fits !! any advise would be nice also any idea where i mite get spares from when i need them

Go here http://www.popularmechanics.com/automotive...rs/4347056.html ....to watch an amazing video of the new BMW 1000r sport bike engine reving and watch the valves open and close. It just becomes a blurr! Wow. Ralphy

Hi, My parents bought me a JCM trails bike for christmas, but i am struggling to work out what the order of the gears are; are they all down? or one down and four up? Any ideas would be grateful Happy Christmas

Hi all, My bantams well on its way to being finished so though I would get myself another project. A BSA Barracuda 250cc. Im going to strip it down and convert it to yet another trials bike as I am planning on competing in a few trials :-) Question - Can I use My spare Bantam hubs and fit them to the bike and if they can will the braking be efficent enough to pass an MOT as I wil take it to local shows?? I Understand this is a popular modification??? With an 18'' wheel on the back and 21'' on the front what is the maximum tyre width I can fit on the rear without modifying the swinging arm. Can the swinging arm be modified easily or is there a replacment that I can…

Hi there. Decided to give the four strokes a bit of a go. I think it would be a good choice considering the forthcoming welsh winter mud fests that seem to plague most events. Was just wondering whether the 08 Beta 4t is better than the 08 Sherco 320 4t. What are their strengths and weaknesses ? I've heard the Sherco clutch is a bit of an on/off situation. I know I have left out Montesa in this comparison but I simply can't afford a recent one.

Not sure if there has been a topic on this before but i couldnt find one anyways so............... Just wondering, went to nord vue yesterday, apart from cabestany, the sherco and beta riders were on 2 strokes. Just wondering why dougie, brown, wigg and all the others dont ride the 4 strokes. obvioulsy the gasgas and montesa riders dont get a choice also in club trials, most people seem to still buy 2 strokes, maybe due to cost? I dunno when the gasgas 4 stroke comes out, will raga ride it, or stick with the 2 stroke? Whats your thoughts?

Did the FIM drop the four strokes only ruling indefinatley? Is it in affect in other countries? I think I read no two strokes can compete in Japan .

Its obvious by the lack of topics in this forum that nothing goes wrong with fourstrokes. Or am i wrong ????

Would any of you folks that have switched to 4 strokers since 05 consider going back 2 stroke if the price or circumstance was right? What if anything would make you change back to 2 stroke? Aaron

These are some pictures of my Moto Guzzi Special. Based on a Stornello 1969 engine placed in a SWM 1980/81 frame. It's now 244 cc. (original 160 cc). I use it in Classic trials. Kind regards, Arie from Holland

Don't know if this has been posted or not, but it's a pretty cool video of the 4T GG in action.

Whilst doing some googling I spotted this Motobi trials special and thought I'd post it. The frame/swingarm and forks are not OEM Motobi parts. cheers, Michael

Hello everyone, I am currently recovering from a cruciate knee ligament operation and therefore I have a bit of time on my hands to do some research as to what trials bike I should purchase next. I also believe that by deciding what bike to get next will help me as inspiration / goal to fully recover and be riding again by the beginning of 2009. I am in my early 30's now and have always ridden 2 strokes (clubman / intermediate level) but did own a 4rt which was sold after 3 months as I seemed to be riding worse probarbly due to me being heavy handed on the throttle. However the problem I now have is trying to predict whether or not trials bike manufacturers will still…

How are people who've gone from 2t to 4t bikes finding the change??? Its taken me about 10 hours to feel really comfortable, but a lot of this was down to bike set up!!

I was wondering what the diameter of the front pipes are on the different 4 strokers, My new 08 scorpa 250fr is about 40mm

Just wondered if anybody has had much trouble with there 4 stroke trials bikes??? i've heard something about a casting breaking inside a 4rt motor??? and rev4 head gaskets?? anybody know of other faults???

Want to see a groundbreaking new 4 stroke mmmmmmmmmmmmmmmmm