17 replies to this topic

[Andy]

John Lamkpin has asked me to post this re setting the float height on a 2008 Beta 2T with a Keihin carb:

 Keihin_carb_float_height.pdf   145.66K   3043 downloads

[Outlaw Dave]

Thanks for the info: Andy

[IKB]

majestyman340, on Feb 27 2008, 09:03 AM, said:

Surely the float level shouldnt need adjusting on a brand new 08 machine?

I think its to stop some of us setting it incorrectly....maybe some already have! Its nice to see the Importer posting good information for us all.

[spudsdad]

maybe the importer gave out some bum info on how to set the float level in the first place?

[Dell]

I got a picture that came from them, it was picture 3 (no other pictures on it) and it said that they SHOULD be parallel when the carb is vertical ? I set it that way and it seems ok anyway so I don't think I'll be stripping it down again in a hurry

Edited by Dell, 01 March 2008 - 08:13 PM.

[JMLFin]

I got my bike a month ago. Today was the first real opportunity to test it properly so I took it like 50km from us to a trial practising place. It started very nicely, I warmed it up like 10 minutes (just to be sure) and then jumped to woods. But it was awful. I thouhgt it hadnt warmed enough so I rode like 10 min more but nothing changed. I realised that when giving little bit more gas, it is running nicely and have power and torque. But when driving slowly and when you would need some power, it was struggling to even keep alive the engine. I then noticed that if I was in somewhat of an angle, the idle wasnt even working and the engine stopped. When in level, it was running also in idle. I then took the bike down to parking place and let it run. I lifted rear tyre up and back down and it stopped.

- 3 degrees of celsius
- Quite humid and windy

My first opportunity to test it was at works parking place. I felt that (after 270cc) the engine wasnt that powerful and low rev torque was missing, but thought it was just because of new bike (temperature maybe +3-5 celsius). Second time when I tested, it was 12+ celsius and it was working very nicely, I even thought that I was stupid to even think that it was so much less powerful and forget the whole issue.

- 12 degrees
- nice and dry

I havent touched anything between these runs. The only thing I did was that I filled the tank with 102 octane gas and used 2% oil mixture as recommend by the importer. Now after receiving news from Beta factory that you should check float level and possibly adjust the needle, I wondered what the hell... they sure dont seem to do these things at factory although first bikes were delivered 6 months ago and actually friend of mine got his then and also received instructions to immediately change needle and float level. But the big difference here is that his bike has been used without any changes since 6 months (not even touched the carb) and mine, which was informed to be"repaired and updated version by the factory so you shouldnt do anything" is now impossible to ride. And now we have this new carb float level instructions that dont seem to effect the older models.

Im quite p****d because I would assume that a factory would have tested new model with changes and when mine isnt even from the first pack or even near, it should work at least as good as the first bikes manufactured.

I hate to open the carb as its in such a stuffed place (particularly as I need to do it out in my backyard where temperature is now +2.4) but I just need to do it.

Anyway, you who have experience of this 2008 250cc bike with Keihin, are you able to send me information what needle/position and jet to use and how much should I open the air screw?

One last question: Can it make such a difference that 12+ degrees it works fine, but 3 degrees its totally usable? Can the 102 gas do this? What about the mixture screw (although not even touched between any of these runs).

[Outlaw Dave]

JLM - Is your bike leaking gas from the overflow tubes that hang below the rear of the motor ?
If it is you should have noticed that you have used a LOT of fuel on your ride.
We had one unit with the float needle not seating properly causing this problem - ran terrible at low revs because it was flooding. ( The quick fix is to take the carb off - yes this means undoing all the 13 screws and pulling the airbox back). - you can usually get the needle to "seat" by turning it around a few times in the base. holding pressure on the needle end - the alternative is to fit a new needle & seat.

[Dan Williams]

Fine tuning my Keihin now so I'm getting good at taking the carb off. It's not necessary to take off anything more then the rear fender and not even that if you can find a way to position the air box boot clamps so you can undo them from the side (I haven't). Here's the procedure.

Wash the bike. Doing carb work on a dirty bike is asking for trouble. Remove rear fender. Yeah it's a pain but the only way to get at air box hose clamp. Loosen both air box boot clamps. Slide air box rubber boot as far back as it will go. This will expose the leading edge of the carb intake bell. Loosen engine intake manifold hose clamp. Open twist grip cable cover on throttle and disconnect throttle cable (gives you a little more slack to work with). Twist carb intake bell away from rear boot and out of front boot. This take a little work to get past rear brake line but it's not a big deal. Lift carb body slightly and pull bottom of body out towards you and the carb is now free.

Reverse to install.

It may be easier with a squirt of WD40 or a little lithium grease on on the rear boot so it will slide on the air box easier.

I also had the floats adjusted wrong this week and had the problem with the bike stalling downhill. Readjusted them to lower the fuel level in the float bowl and it is now fine.

Edited by Dan Williams, 28 April 2008 - 02:04 PM.

[JSE]

Dan Williams, on Apr 28 2008, 09:02 AM, said:

It may be easier with a squirt of WD40 or a little lithium grease on on the rear boot so it will slide on the air box easier.

Dan,
Another trick is, next time you have the airbox off, use a Dremel tool to radius the very front, inside if the boot, where it slips over the front lip of the bell of the carb. The boots of most airboxs are molded with a sharp edge to the front, inside of the "tube" and this makes it catch the "lip" around the front of the carb bell (which is designed to keep the boot from slipping off). Cutting a radius at that edge will allow the carb bell to slide in even when it's at an angle to the boot.

Jon

[Dan Williams]

Thanks Jon,

Not really necessary with the Keihin though. Once the boot is slid back towards the air box the intake bell clears the boot by about 1/4" and it looks like the air box part is just a straight tube. It's actually easier then the Mikuni now that I've figured out the sequence. Now if I can figure how to do it without taking the fender off...

[JMLFin]

Outlaw Dave, on Apr 26 2008, 11:35 PM, said:

JLM - Is your bike leaking gas from the overflow tubes that hang below the rear of the motor ?
If it is you should have noticed that you have used a LOT of fuel on your ride.
We had one unit with the float needle not seating properly causing this problem - ran terrible at low revs because it was flooding. ( The quick fix is to take the carb off - yes this means undoing all the 13 screws and pulling the airbox back). - you can usually get the needle to "seat" by turning it around a few times in the base. holding pressure on the needle end - the alternative is to fit a new needle & seat.

I need to update my situation. First of all, my bike must have been a monday piece. After three runs we didnt manage to get it running like it should. I was so frustrated and dissappointed but naturally willing to get it working. I asked the importer to take it with him and adjust everything so that it would work (I had opened the carb like 10 times, so I really know now how to do it - its actually not that tricky at all and takes about 2 min). He didnt manage to get it working by adjusting the floating level or anything else that can be done without major changes. He then ordered new carb from manufacturer. It came in 22 hours that in these circumstances is absolutely awesome. He changed it on friday evening and brought the bike to a training camp next saturday morning. Bike was working ok, but wasnt responding to low revs like would be expected. It was also leaking fuel so much that I had to refill the tank just after light 2 hours of driving.... something wasnt right. I then took it home and next time when I was riding I noticed that there is something very strange. Engine was knocking like it would run very lean. I came back after 20 min of ridind and we tried to service it there. Nothing helped. Importer then kindly suggested that lets go to his place and take a look at it. We opened everything and finally as nothing could be found, we opened the new carb and noticed that there were a lot of dirt inside the cup and jets (why not do it earlier - because he had opened it and we couldnt believe that just after few hours drive it would be that dirty). After cleaning the carb it ran nicely. I took it home and next time when I drove it, it was coughing in the beginning and again, in low revs it wasnt responding to throtle. It did raise the revs but came back down like with multiple up`s and downs. I then asked an elite guy to test it and he said immediately that this isnt working like it should. I then asked another guy and same response, so at this point I could say finally that it wasnt between my ears.

Well anyway, anyone can imagine how dissappointed I was, although I have to say that Beta`s importer was more than helpful but with limited knowledge and experience of this new Rev3 with Keihin, he wasnt able to help in the end. Its sad to say but I dont like to pay almost 6000e for a new bike that isnt working from day one. Mine was obviously a "monday piece" but I know its serviced and repaired now and runs nicely. Yes .... I got so frustrated that I returned the bike with a gentleman`s handshake with the importer. He did everything he could and I need to thank him, but this time my patience ran out.

I need to stress here that there were nothing wrong with the bike, only the carb. It seems to be causing a lot of trouble for us new Beta owners. As Im more or less warming up an old hobby, I dont like to spend hours and hours repairing my new bike. For someone that has the facility, time and experience might disagree with me, but this is the case anyway. New Beta is fantastic piece of trial bike, but unfortunately manufacturer`s quality control with new Keihin seems to hit the rocks. I still dont think that buyer should repair, adjust and service new bike and spend hours and hours just to make it work.

[JMcK]

Getting dirt in the carburetor has nothing to do with the quality control of the Keihin carb...

Based on what all you are saying, it sounds as if you have dirt in the gas tank, the air filter is not sealed properly allowing dirt and debri to enter the carb, or the or the connection to the rear of the carb and the air filter is not sealed properly allowing dirt to enter.

In my 4 decades of working on motorcycles I have never seen a "bad" carburetor that had to be replaced. I have seen carburetors that were worn out, but never a bad carb from the manufacturer.

You need to find someone who understands basic motorcycle mechanics, and let them look at what is going on. You can clean the carb a hundred times, but if you do not locate the source of the dirt entering the carb then you will clean it again for hundred and first time.

We were at a trial yesterday that had seven 2008 Beta Rev3's entered and not one of them have experienced carburetor problems.

[JMLFin]

You are very right. I was not referring to Keihin because of dirt getting in there but more or less the fact that so many have had problems with setting it up properly. Manufacturer attached a note and a package of jets and a needle to all first stage delivery bikes. In my mind this means that it wasnt properly tested by Beta and that "fix this before you ride" message was quite funny. On the other hand, those first stage delivery bikes havent had a problem but those that should have been "already tested and fixed" seem to have it. Its mainly float level and needle. I have also seen a tape aside of carb that says "ok". This was placed by manufacturer. I didnt have this, my friend did and his is working fine.

I dont want to blame anyone, either carb or beta, but the fact is that there are way too many problems in the first place to be fixed with the carb, that although I do clearly understand that we are talking about racing bikes, I still dont think thats its my problem to pay the bike and then service it before I can run with it. Its a shame for the importers, it means more work and less profit as I dont think that manufacturer really compensates their work. Okey its a new set of package with Keihin carbs, but still....

[Dan Williams]

Yikes, it shouldn't be dirty at all. Maybe after a really dusty trials there will be some dirt in the intake bell but not in the float bowl. It almost sounds like you have some bad gas. If you're dispensing from an older gas can, especially a steel one there may be corrosion inside that sloughing off into the fuel. There were reports in the early days of the Verlicci aluminum frames of welding spooge in the gas tanks but that was years ago. Clean the carb, gas tank and purge the fuel system and dispense fresh premix from a new plastic gas can and see if the issue returns. I'd be surprised if that didn't fix it.