Questions 'bout Tillotson carbs.

[Ac0X^]

Hi there.

I'm the (un)lucky owner of a 25.5 Tillotson cart carb.

I have som strange problems.

After fitting it yesterday, i took of the vacum hoose, cause there is no vacum on the carb.

After i started it, it ran fine.

Then i found a quiet road (it was quiet before i came) to test the shit.

After some adjustments it ran ok.

BUT. Today, it starts perfect, but after 10 secunds, the engine stops.

After some checking, i found out that the gas won't ran to tha carb itselves as yesterday.

The only way i could hold it running, was if i sucked in the vacum hoose.

What the fuck is wrong ? In ran perfect yesterday ?

The carb is fitted on my NRG a long with a Manston cilinder, HiRace II exhaust and so on.

Help!

 

[Speed]

I do not know how your bike started at all. The Tillotson Carb I have has to have the vaccum hose connected to the crankcase in order to start. The crankcase compression activates the diaphram to pump fuel into the motor.

The vaccum hole is normally located in the front for the carburetor. It is very small. Depending on how you mounted your carburetor, you should be able to drill a small hole through your reed cage outer flange to access the bottom half crankcase AFTER the reeds. When you re-mount the carb the hole needs to be able line up right into the crankcase.

You also need to set the pop off pressure to the carburetor. It is a small spring inside the carb. If the pop off pressure is adjusted too low the bike will not flow fuel & the bike will not start. If it is adjusted too high it will flood the bike. Most Jet Ski mechanics have the tool to adjust the pop off pressure. There is a scale that you use to adjust the pop off pressure depending on the size of your motor you are using.

If my bike sits too long I have to give it a direct prime in order to start it. I have to remove the air filter a pure a little gas down the carburetor.

Added Speed

 

[Speed]

How did your motor run with the carb. Did it make a big difference?

Added Speed

 

[Ac0X^]

Originally posted by Speed
I do not know how your bike started at all. The Tillotson Carb I have has to have the vaccum hose connected to the crankcase in order to start. The crankcase compression activates the diaphram to pump fuel into the motor.

The vaccum hole is normally located in the front for the carburetor. It is very small. Depending on how you mounted your carburetor, you should be able to drill a small hole through your reed cage outer flange to access the bottom half crankcase AFTER the reeds. When you re-mount the carb the hole needs to be able line up right into the crankcase.

You also need to set the pop off pressure to the carburetor. It is a small spring inside the carb. If the pop off pressure is adjusted too low the bike will not flow fuel & the bike will not start. If it is adjusted too high it will flood the bike. Most Jet Ski mechanics have the tool to adjust the pop off pressure. There is a scale that you use to adjust the pop off pressure depending on the size of your motor you are using.

If my bike sits too long I have to give it a direct prime in order to start it. I have to remove the air filter a pure a little gas down the carburetor.

Added Speed

Thank you very much. I'll go right down and play at bit with it.

And yea, it made a difference

Before i had a 24 Mikuni Flatslide, and the gasrespons with the Tillotson was a bit better.

 

[monstaboy]

Use a 'benzinekraan' of attach your vacuum hose on your 'spruitstuk'.

 

[Ac0X^]

Originally posted by monstaboy
Use a 'benzinekraan' of attach your vacuum hose on your 'spruitstuk'.

What it a benzinekraan ?

 

[Running_Sp]

a petrol tap , you can "lock" your fuel tank by a switch and open it so the fuel keeps running out .

so you can buy that and install it on your fuel tank instead of the vacuum system.

 

[R5 man]

a fuel tap, or what's it called

 

[Ac0X^]

Originally posted by Running_Sp
a petrol tap , you can "lock" your fuel tank by a switch and open it so the fuel keeps running out .

so you can buy that and install it on your fuel tank instead of the vacuum system.

Aaaarh i see

I'll figure something out

Thank you very much you all

 

[R5 man]

piaggio has got fuel taps, so you can use one of piaggio, 2 easy