si7 Posted February 16, 2011 Report Share Posted February 16, 2011 Hi Guys Still looking for cheapish starter bike and came across a Beta Techno 270 yesterday, looks in good condition from the pics. I appreciate a 270 is probably not a good capacity to start out on but I do have a little off road experience and would take it easy. Are there any specific weaknesses on this bike to look for? Or common mechanical issues on say the 270? And I presume there is a 270? (wondered if it was a 250 overbored) It's described as a Dougie Lampkin replica, again not sure if there is such a model. Looking for a light bike too, maybe they all are, but wondering where the Beta Techno sits mass wise. Bit of a novice so any advice greatfully received. Cheers Quote Link to comment Share on other sites More sharing options...
si7 Posted February 16, 2011 Author Report Share Posted February 16, 2011 Another question, what is the second screw on cap on the tank, is it for 2 stroke oil? Thought they were premix? Quote Link to comment Share on other sites More sharing options...
beta_trials Posted February 16, 2011 Report Share Posted February 16, 2011 Yeah their premixed fuel only. The other cap on the left is the Coolant resivour. When you pull the tank/seat cover off its clearly visable. Quote Link to comment Share on other sites More sharing options...
dan williams Posted February 16, 2011 Report Share Posted February 16, 2011 What's that big leather looking thing behind the gas tank? Quote Link to comment Share on other sites More sharing options...
si7 Posted February 16, 2011 Author Report Share Posted February 16, 2011 It's got a saddle, I asked about it thinking it was a home made thing but it's something from America apparently. Suits me, I like a sit down now and again Quote Link to comment Share on other sites More sharing options...
dan williams Posted February 17, 2011 Report Share Posted February 17, 2011 It actually looks pretty good. Quote Link to comment Share on other sites More sharing options...
trialsmotopat Posted February 17, 2011 Report Share Posted February 17, 2011 I got one of those the other day for what I think was a bargain - how much you looking at handing over for that one? Mine had usual Beta carb issue which I sorted relatively easily by actually looking at what the carb and float bowl was doing - in my opinion (and my carb is now fixed and doesn't leak) the manuals I've seen show to set the float height by aligning to the top corner of the furthest 'turret' and I believe this to be wrong and probably why they all come out the factory with leaky carbs. A bit of trial and error and I got two carbs (got a spare with the bike) set up in 2hrs max. I think from memory I decided the float height was not the issue, but the fact the tab that pressures the float needle needed tweeking - not much but enough so it fully seated the needle when the carb was full. (it was not doing this and fuel kept p****** in even though the floats had maxed out and then found it's way out of the overflow tubes). Haven't ridden mine hardly at all - only a few hours but it seems pretty perky. Apparantly mine had a recent new top end (haven't they all ) and does seem pretty good, starts first or second kick. Pulls well enough with no issues or unusual noises. Fan works as it should and all nuts and bolts still good. Quote Link to comment Share on other sites More sharing options...
dan williams Posted February 18, 2011 Report Share Posted February 18, 2011 There is only one overflow tube and it comes out of the bottom of the carb. The two tubes that come out of the sides of the carb are pressure vents for the float bowl and are not supposed to leak fuel even if the float valve is stuck on. The reason they do leak is the tubes are so long they end below the fuel level in the float bowl so if gas gets splashed up into the vent circuits and starts flowing down the tube it acts like a siphon and keeps flowing until the flow is interrupted. There are two common fixes, one is to change where the vent circuit is exposed in the float bowl which involves drilling of the carb body. The other fix is to just nip a hole in the vent tubes about halfway up the carb body. Nipping the hole in the tubes is something I've done to many Betas and it works very well for no money. OK there is one other fix and that is to route the vent tubes up over the carb but that can lead to the bike running rich if fuel gets into the tubes and returns to the float bowl. Quote Link to comment Share on other sites More sharing options...
trialsmotopat Posted February 18, 2011 Report Share Posted February 18, 2011 There is only one overflow tube and it comes out of the bottom of the carb. The two tubes that come out of the sides of the carb are pressure vents for the float bowl and are not supposed to leak fuel even if the float valve is stuck on. The reason they do leak is the tubes are so long they end below the fuel level in the float bowl so if gas gets splashed up into the vent circuits and starts flowing down the tube it acts like a siphon and keeps flowing until the flow is interrupted. There are two common fixes, one is to change where the vent circuit is exposed in the float bowl which involves drilling of the carb body. The other fix is to just nip a hole in the vent tubes about halfway up the carb body. Nipping the hole in the tubes is something I've done to many Betas and it works very well for no money. OK there is one other fix and that is to route the vent tubes up over the carb but that can lead to the bike running rich if fuel gets into the tubes and returns to the float bowl. I can't go and have a look now, but I know I'm missing a tube or two off the carb so it's at least one from the top - but mine leaked and now it doesn't after the work I did????? Not saying I'm defo right as I'm deffo not an expert and it seems to have been discussed and figured out at lenght - just wonder how come I don't have a leak?? My bike didn't have a full set of pipes on the carbs when I got it and leaked, and I'm pretty sure the pipe is back on how it was. Surely it's not as easy to remove a pipe? Only used my bike for a few hours on a mate's farm where he has some sections from where a club goes and also an 'enduro' loop with some whoops and table tops thrown in with some logs etc 3rd and 4th gear stuff opening it up. So I gave it some beans and didn't seem to have any fueling issues?? the only prob I had was I think one stall when the sumpguard splattered onto a big log and I stopped dead. I put that down to one of those things..... I guess I'll never understand the alchemy of carbs, and fingers crossed mine stay good Quote Link to comment Share on other sites More sharing options...
trialsmotopat Posted February 18, 2011 Report Share Posted February 18, 2011 (edited) The two tubes that come out of the sides of the carb are pressure vents for the float bowl .... The reason they do leak is the tubes are so long they end below the fuel level in the float bowl a ) if they leak fuel they are 'overflowing' b ) why isn't the mod to just shorten the tubes? -i think i read something about drop in pressure, but as I said i don't have both tubes, and i'd imagine the if the tube lenght were critical then the carb is working to some pretty crazy tolerances with the variable being the lenght of a tube!!!! Edited February 18, 2011 by trialsmotopat Quote Link to comment Share on other sites More sharing options...
dpmotorcycles Posted February 20, 2011 Report Share Posted February 20, 2011 It's got a saddle, I asked about it thinking it was a home made thing but it's something from America apparently. Suits me, I like a sit down now and again i am liking the seat Quote Link to comment Share on other sites More sharing options...
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