gasgas

putting a seal in the freezer does help a little from own experience.

Maybe GG Uk can elaborate on this one, since they read our topics

I absolutely agree with everybody that smaller carbs produce better response down low, the fuel signal is much stronger and because of that the mixture will have a better mix Keihin and Mikuni's what is the diffenrence? Beats me.. The replica's of the keihin, the oko's, yes cld be a good choice for the money spent. Here in holland they sell via the scooters shops a lot. They get good revues. Well, during these cold days overhere, i like to have something on hand.. So i give the divider a go, I just glue it in the carb for the test and see what happens. cheers

what a scenery, wauw. It looks a bit like the south of France. Technical stuff i say.... real enduro country. Oops i forgot. You were asking about yr trials bike turning it into a trails bike I ride a enduro husqvarna 250cc 2stroke, and one thing i don't like of my GG is the suspension. When i drive my GG fast it scares the hell out of me. The suspension is way too fast. Trials suspensions are made for working at walking pace not at the running pace we travelling over these paths. You cld however modify the front suspension rather easy, but you have to go into them. (perhaps heavier oil cld do the job but i doubt that) So more damping control wld be my 2 cents. The rear shock cld do the job turning the clicker in till you find it statisfied.

Luckily i pressure checked the engine before putting it back into the frame, and yes there was a tiny leak around one of the bolts, but not to worry about. The inner pressure test is higher psi than the engine psi when running.

If you look at the entrance of the carb you can see that i beveled the edges. Normally there is a lot of material sitting here, unnessary in my opinion. By removing it you create more entrance area for the inlet to flow. It is easy money. Inlet trajects shld be as straight as possible without any ledges, ridges etc. Here you look into the inlet manifold. I dremeled away some material, which show as blankish. This material was actually in the way of the inlet traject. Again by removing it and smoothing things out, you create better flow, which is crucial for pickup response.

Wow, Steve you are a brave man

I ve read all the topics at the mx-forums so am familiar with all the agruments pro and con. I am not looking for more hp's but more for throttle response although i find my decent at low throttles. Jtt, the idea of both ends sounds good, i will give it thought. The whole idea of throttle responce is too avoid lugs and/or swirls where flow is obstructed when you crack open the throttle. Am i right in this thought? I already modified my reedblock by looking tru it and dremel all the ridges and ledges smooth. From the factory you can see that the reedblock and stuffer have some issues in corresponding to each other. The reedblock is overlapping the stuffer creating a big ledge. Keep you all informed about any further news....

Was thinking about modifying my carb(dellorto phbl)like is done when you install power-nows or powerblades. It seems that the idle circuit can benefit alot of this. Anyone tried this or done this or has any suggestions why not? The idea behind is that with slight throttle openings the big venturi avoids good airflow cause of the turbulence. By dividing the venturi with a powernow/blade the venturi is halved so creating better lineair airflow velocties, less turbulence, hence better atomization. Any comments? It is easily done by using a sheet of thin alu glued in the middle of the venturi... it is easily withdrawn also

Hi all, well a running time of 2 almost 3 hours on Sunday really loosened things up in the egine department. The tightness is all gone now and when you grab the flywheel it just turns easy as it shld. Beforehand you could feel the drag against the seals etc but now . Looking via the exhaust opening into the cilinder didn't show signs of trouble. Cilinder is showing some nicely crosshatch marks of the honing and pistonrings are still moving in their grooves. Not that i expected otherwise but it is nice to be sure. I am now concentrating on the mid-muffler as i found it carbonized like crazy. Cleaning this baby is asking for some rather rigorius action. I have to open it up tru the side and trying to clean it that way. Stupid that they did weld this thing up like they did. It is not servicable in a normal way. Keep you all posted. Meanwhile i have to work on my endurance and in combination with this "new" engine shld send me up to the club podium next club event

Yesterday i took the bike out for a trainings-practice at the club in Apeldoorn. Two and a half hour trainings session didn't reveal any mistakes in the engine department, lucky me My main concern each time is to get the clutch working again as she should. Bleeding the line is always a trouble but since i am using a syringe of 50ml i back bleed the whole system from the slavepiston up to the masterpiston. That seems to help a lot as the air bubbles rise up with the flow of the brakefluid pumped upwards. But nevertheless there are always airpockets that won't go easily out. Pumping the lever and tapping the system always create some air bubbles escaping from the flowhole in the masterpump. Tonight i will losen the header exhaust pipe and have a look at the piston and rings to see if there are any weird signs telling me something is wrong afterall, but i don't expect them to be seen as i feel everything is working oke. I am glad that the gearshifting is now up to par, and that i did wise to put an extra washer between the drum and the gearshaft to lift it 0,5mm up. That seem to do the trick. Looking at the exploded view of the engine they did not put in that washer and that explained maybe the bad shifting from 3rd to 2nd. So you see also in spain they are only human. I found it nice to open up this little engine and hope that every body who read this topic found likewise. Ciao george

I assume that a txt80 works with a Dellorto phbl carburateur? Turning in the fuelscrew must give you signs of leaniness, if not, yr pilotjet is way too big. You state that you use a 50 pilotjet? Can somebody tell us whether that is oke? edit edit: i just found out that we are talking a airscrew here. So turning the screw in means richer and out is leaner. maybe here is the culprit. Check this website: http://www.gasgas.com/Pages/Technical/Snel...ting-specs.html

What about silkolene that is so special that i shld use it? Starting a bike cold without the choke tells you enough, i wld say. It tells you either to much fuel in the carbbowl or to big a pilotjet. If the float is oke, leave it, since altering infects the whole throttle range. Do you leave the petcock on, while transporting yr bike, maybe yr floatneedle is worn. Anyway you have to go tru all the variables to solve it. succes.

Hi everybody, the engine is back in one piece, and doing a leak down test showed no signs of any leaks whatsoever. My first impression of the engine when i first put it back and tightened all the bolts was that it just felt incredible tight. Like everything was dragging. Offcourse news seals create a lot of drag, but i cld not imagine it wld feel tight like this. I had my doubts about everything but since the crank sits in the bearings with a slip fit i cld not be that the bearings where out of true. or something like that. Anyway started the baby this afternoon, after getting me some fresh petrol mixed with 1% bio synthetic 2stroke oil, and let it idle for a couple of minutes rode it around checking the shifting. I really felt happy when i realised that the shifting was cured. With distinct claks it shifted up and down tru the gears. I also changed the carb setting and went for a 36 pilot(from a 33) and a 118 main(from a 112) to compensate a little for the cold wheather around here, needle 2nd clip from top. Tomorrow i will do some training with the new engine and see how things go. Right now i feel satisfied knowing that i really did a good job. Shifting is cured. New bearings are installed. New rings pupm up the compression. New cranksseals must do a good job keeping the gearoil away from the piston. Here a few last piccies

Report of last night. Both mainbearings are now seated. The last one just popped in, with the freezer/heating trick. No hammering what so ever. The seal was more trouble as this fit is just too tight to let it drop in by itselves. With all bearings placed i put the gears back in. Without fitting the crankshaft yet, i putt the cases together to check on the shifting. Strange thing occured the shafts wldn't turn, like they were jammed. After some disassembling and again assembling i found out that the cases were not sealed together properly. It didn't really show a gap or so but a tap with the hammer putt things right. Scary how tight the tolerances are. An other funny thing i discovered is the tolerances between a new bearing and old bearing. The old mainbearings (it is a 6205 C4) just slips on and a new bearings needs a tap with a hammer . Later...again

cdn, the pickup coil is easy accesable but to alter the timing you have to widen the bolt holes which keep it bolted to the case. To be able to work on it, you have to pull the flywheel with a extractor and loosen the stator and pickup coil from the engine.

maybe But yes, retarding the timing will help when using lesser octane petrol, since lesser octane petrol burns faster then higher octanes you can help the egine with backing off the timing a tad. What year is this 280, as with mine bike, (a pro 2002)i have to alter the position of the pickup coil which trickers the cdi.

Hi, a lot of bikes/cilinders use o rings nowadays. The positives are good sealing and good heat transfer. I wld say that heat transfer is the main reason for the o-rings usage. The negative side is the fix deck height. With gaskets you can alter the squish height rather easy. I think Arieltt means the gearshifters, not the clutch, but correct me if i am wrong. With a 1993 bike, i wld change any bearings/seals/components which are doubtfull. It has seen a lot of hours and when you want it for keep just make it completely fresh inside out. Happy wrenching

I just jumped in, somewhere in Februari this year, but realises that nobody knew me then, or now I am the guy from overseas, an elderly young of 42 years, who started in Januari when i found it was time to follow up my childs dream. I bought myself a Pro 250cc Gasser from a frensch speaking belgian to discover at home that french speaking belgians don't like to clean airfilters. So this brings me to my other hobby, wrenching. I am not professionally skilled but that won't bother me a bit. I have made some expensive errors along the way, like seized pistons etc but nothing that stopped me permantely. Beside the Gasgas i own two more bikes, a 250cc 2 stroke enduro bike and 125cc stroke cross bike, both are Husqvarna's. I started riding offroad and enduro's but am now a trials believer. A girlfriend and three kids along with these bikes is what keeps me happy. See you all one day

Seals start, at one point, to leak as the seals itself will fade over time. I can comment that my seals were leaking oil, but the bearings were absolutely 100%. The seals lifespan is much shorter than the lifespan of the mainbearings, so you can get away with only fresh seals. I had to remove the bearings to get the seals out and by doing so i destroyed the bearings. But if i cld have safed them no problems with using them again.

Todays report, a bit of happiness and sadness . First the happy part. I finally were able to remove the small bearing from the left case in which the clutchshaft is running. The little $$# was very hard to remove without the proper tools. Which i don't have. But with some creativity i succeeded. The sad part. Never hit a bearing on the inner race. You know it i know it, so why did i do it anyway? Perhaps i thought that for just one little hit it cld not hurt. So i destroyed a new crankshaft bearing, which set me back a 15 euros. I heated up the case halves with our kitchen oven, 160 degrees celsius, and took the bearing out of the freezer, minus 18 degrees celsius. Thought it wld just pop in, but my o my, he did not . Taken by the suprise i immediatly started hitting the outer race(offcourse) but then when it moved deeper, i did not have a proper tool(again) to hit anymore on the outer race so i continued on the inner race. Well, that moved it deeper, no question, but after that the bearing rolled rather oddly. Like it sort of had this grooves in it . I will call the shop tomorrow to send me one more. Learned of that bearing i did the other one nicely So now the left case is ready, with two new bearings in them and the right will have to wait another 24 hours. Later ...

Isn't there a exploded view of the engine somewhere on GG usa?

I wld suggest that the fresher the engine/bike the better. If you are looking to new versus new than i have no idea which one, but comparing used against new is easy. Go with the freshest bike.

Matt can you elaborate on: grinding the ports. It is easy said, but what part do you suggest to grind? I feel you have done this mod with satisfaction.