hi

should the 151 350 have a breather hole in filler nut like the primary filler cap?

the primary filler has a hole about 1mm on the side.

but the filler for gear box under carb has just got a slotted cap with no hole,

I was reading a post from 2008 and guy had over heating problems he had no vent on his gear box

as mine does run bit hot I was just wondering should mine have a vent ?

cheers

hi my 199B has a nut with a vent tube but i do know there is also a littel vent hole just above the front sprocket. you can buy a nut with a breather just put a tube on it. but if its runing hot it could be a number of things like timming or the carb my not be set up proper. but bare in mind these bikes do get hot if you clutch case or magneto case gets hot then somthing is wrong.

No your Bulto 151 should have a plain filler plug like this one

No your Bulto 151 should have a plain filler plug like this one

that's what I got paul so is there no breather for the gearbox then anywhere

cheers

Hello. Your 151 has a small hole through the case around the kickstart shaft somewhere. It is only about 1mm so it is a bit hard to see. That is the gearbox vent. Graham.

yes there is a small vent just above the kickstart shaft on the crank case some times gets blocked spoke it with some wire. you can still have a breather on the filler as an exra. if its still over heating then its somthing else.

cheers guys found the hole blocked solid .

all free now so hopefully make a difference

thanks for your help

hi my 199B has a nut with a vent tube but i do know there is also a littel vent hole just above the front sprocket. you can buy a nut with a breather just put a tube on it. but if its runing hot it could be a number of things like timming or the carb my not be set up proper. but bare in mind these bikes do get hot if you clutch case or magneto case gets hot then somthing is wrong.

bondy

you say if clutch cover or mag cover gets hot there something wrong obviously it will get hot but what do you mean ?

too hot to touch ?

or just hot

mine gets hot but I can touch it and bike seems to run fine

I'm interested to understand this as well....

but bare in mind these bikes do get hot if you clutch case or magneto case gets hot then somthing is wrong.

They run hot but there's something wrong if they get hot? I'm sure there is a typo in there somewhere but I still can't make it out... They're going to get hot due to heat transference from the cylinder...

You don't need the vented plug for the gearbox. And if you fit one the chances are that the gear train will try and throw most of the gearbox oil up it - just like the clutch does on the later bikes with the vented filler plugs.

The only damage you're going to do to the gearbox is if it runs dry and seizes the bearings. It's not going to run hot because of a blocked breather.

hi sorry id had a few beers. yes if its to hot to touch then somthing is not right.

right solved the over heating timing was out although it started and rode ok but after 10 -15 min it was cooking.

done timing and been out for hours ride and now I can hold my hands on side casing before could not touch them.

just glad never cooked engine .

I got all the right oils in gearbox and clutch .

but quite a bit of oil comes out the breather hole on the clutch filler there is a pin hole in the side of the screw.

I appreciate its a breather just wondered if its normal for oil to come out and trickle down clutch cover ?

I only got 300ml oil and know its not coming from filler and washer but deffinatly from the breather hole

any help appreciated

just put a normal plastic plug in the clutch case. all my bultacos have these on and i dont have any oil coming out. even with the tube on they do still let oil out just change it evrry 2 trials

Hi Dave. The primary case holds 300 ml of oil if the primary case has been off and it is completely empty. If you have only drained the oil then you only need to put 260/270 ml of oil back in as they hold a bit of oil in the case. It sounds as if there is a little bit to much oil in there for the breather to be leaking. The gearbox is the same it holds about 50ml of oil if it is only drained so you only have to put about 550ml into it after draining. Cheers Graham.

hi Graham sorry to butt in ive just changed my gearbox oil i only put 500ml in and ive noticed it leaks when the bike is over abit to the R/H side its not coming for the drain plug. its dripping from the front sprocket so am thinking its 1 off the seals behind the sprocket. i had this problem on a 199A i used to have frew years ago change all the seals behind the sprocket still was the same i never got to the botom of it i hope this 1 is not the same. theres a oring binhind the seal and tophat may be that are the littel seal on the end of the final drive shaft i know its normal for abit to come out ill have to investagate more fun.

Hi Bondy. You should be able to see where it is coming from if you pull the counter shaft sprocket off. I have had the seal that goes in the middle of the inner and outer counter shaft leak before. Any of them you should be able to change from the outside with a bit of fiddling and unorthodox work. The manual says to pull the engine in halves to change the countershaft seal but I have done it from the outside before. Cheers Graham.