Partner 370 Won't Start - Help Needed!

[Stubby]

1 hour ago, bmp01 said:

I should have paid better attention to your original post. .. so it's been apart already . Two questions, 

1) Are you seeing fuel in the primer bulb?  If so,  that should have filled the metering chamber with fuel.... and it should then at least cough on 2-3 pulls. If no fuel in the primer bulb then, did you get the fuel lines swapped over? Or the filter is completely blocked or the metering valve isn't opening (metering gasket upside down? Check metering lever setting).

2) Is the choke mechanism operating as it should? You need it to create the vacuum to suck the fuel in. ..

 

If you do take the carb apart again,  confirm all jets etc are unblocked with something like WD40 spray through one of those thin tubes.  DON'T use compressed air at full pressure that will knacker the one way valves (one in each of the low and high speed circuits). I've got a short length of silicon hose which is very soft and can be pressed onto the entry to the drillings and sealed by hand pressure - blowing (and sucking) confirms drillings are clear and one way valves are working .... (or not). Doesn't taste the best but you learn a lot 

 

At some stage it might be worth popping some fuel down the spark plug hole, just to confirm the engine will run once the fueling is sorted....

 

Let us know how you get on. 

 

bmp01

 

 

He says he can see fuel being pulled through when he primes it .

 

- 

 

[bmp01]

Ah,  but did he? You're probably right but i wanted to confirm the fuel in the pipe was getting all the way to the primer and not just shuffling back and forth - seems pedantic maybe but sometimes it's not 100% certain which way fuel is flowing when it's pulsed with a primer. .... or maybe that's just me 

 

 

[spudulike]

Most likely that the metering arm needs a tweak, try lifting it around 1/2 mm. Worth pulling the H&L screw and blasting done WD40 or carb cleaner down there and wind them out around 1 & 1/4 turns, should be one turn but if it is lacking fuel....

 

[GardenKit]

Spray some carb cleaner directly into the carb throat with air filter off and then pull. Normally a saw will then start and run for a few seconds. This pretty well proves compression and ignition. Then it's time to work on the carb. Takes a few seconds to narrow it down like this.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[logedd in]

On ‎30‎/‎09‎/‎2017 at 22:14, GardenKit said:

 

Spray some carb cleaner directly into the carb throat with air filter off and then pull. Normally a saw will then start and run for a few seconds. This pretty well proves compression and ignition. Then it's time to work on the carb. Takes a few seconds to narrow it down like this

 

Good advice Barry or bit of fuel down plug hole shorly must be the next thing to try 

[Darrin Turnbull]

Good advice Barry or bit of fuel down plug hole shorly must be the next thing to try 

Or wet the filter with fuel .

[_Chris]

Hi again and thanks for all the interest shown in this topic.

 

I noticed that air is being drawn out of the carb and into the primer bulb along with a little fuel when I prime. The feed line is full of fuel and air free. So I suppose air is leaking into the fuel somewhere in the carb.

 

I took the cover off the metering chamber and did the suck blow thing that you suggested on the one way valve under the brass retaining cap in the picture and found that I could draw air in as well as blow it out - so I'm guessing that it's knackered. I did the same thing on the H and L  holes after removing the springs and needles. I could both suck and blow on these too - not sure if that's supposed to happen.

 

Anyway, I've ordered another carb from fleabay - I'ts only £15 which is probably less than the cost of a kit to do an overhaul, which to be honest, looks a bit tricky!

[bmp01]

1 hour ago, _Chris said:

Hi again and thanks for all the interest shown in this topic.

 

I noticed that air is being drawn out of the carb and into the primer bulb along with a little fuel when I prime. The feed line is full of fuel and air free. So I suppose air is leaking into the fuel somewhere in the carb.

 

I took the cover off the metering chamber and did the suck blow thing that you suggested on the one way valve under the brass retaining cap in the picture and found that I could draw air in as well as blow it out - so I'm guessing that it's knackered. I did the same thing on the H and L  holes after removing the springs and needles. I could both suck and blow on these too - not sure if that's supposed to happen.

 

Good observations. 

So was the metering chamber full of fuel or not? 

Take the pump side apart too. Fuel or not?  Is the pumping diaphragm intact? 

 

IF the pump side is good,  AND the metering diaphragm is sound, then the only way the air is being drawn into the fuel is through the jets in the carb. ....normally in the running engine the're flowing fuel into the engine, it's only the one way valves that stop the purge system from drawing air backwards through the jets. ....

 

 

Edited October 2, 2017 by bmp01
to add the words i wanted to include !

[bmp01]

1 hour ago, _Chris said:

I took the cover off the metering chamber and did the suck blow thing that you suggested on the one way valve under the brass retaining cap in the picture and found that I could draw air in as well as blow it out - so I'm guessing that it's knackered. I did the same thing on the H and L  holes after removing the springs and needles. I could both suck and blow on these too - not sure if that's supposed to happen.

Your carb looks straight forward,  fuel in past the metering valve,  fuel into engine via the single brass insert jet and fuel to primer via drilling and brass pipe. Are there any other drillings or jets coming off of the metering chamber?  If not then doing the suck and blow test through the brass insert (WITH both the adjuster screws fitted and adjusted to 1 turn out) should tell you if the one way valves are working.  I would repeat after feeding some WD40 into the same brass insert - sometimes that can "wake up" the valve.

Blowing through the adjustment screw holes doesn't tell you anything..... 

 

A carb rebuild is usually limited to replacing the diaphragms, the little gauze filter and the metering valve / metering arm. You can replace the little aluminium plugs but it's only necessary if the passageways below are blocked and you need to gain access to clean them.  So, normally it's take carb apart,  clean,  reassemble with new bits. ...not too hard. 

 

So anyway,  you did check the diaphragms for holes ???

 

bmp01