Trouble starting...

**bogan** · 26th March 2010, 12:04

and when it would eventually start, how did it run, missing anywhere?

**MSTRS:Me** · 26th March 2010, 12:17

Originally Posted by magicmonkey

well, it would start but it was bloody hard to do, took ages to get it to catch properly and spring into life. So, I decided to check out the sparks, wound up changing the leads for ones actually meant for a bike (rather than the car leads it was using) and changed some o-rings on the carbs at the same time. Now there's no life at all, engine turns over but doesn't even fire one cylinder off let alone spark into life ...

As for the float heights, that's a job on tonights list. I'll post on how it goes but I have had a brief check while draining the bowls and it looked roughly ok at that point (earlier in the week, after the problems started)

It is possible that the float height is not variable. A lot of Jappers have the float and the fitting for the shutoff needle molded all in one.
As for the rest of the post...there is a lesson in there. DO NOT FUCK WITH 2 different critical things at the same time. 'Fix' one...check...'fix' second if necessary.

**scumdog** · 26th March 2010, 12:19

Hmm, you've got good spark, it APPEARS you have fuel getting to the motor - however you take the plugs out after a wiz-wiz-wiz session with the starter motor do they look at all wet/smell strongly of fuel?

Cos if not it's likely that no/not enough fuel is getting into the motor.

And I cannot recall if you mentioned it but how old is the fuel?

**magicmonkey** · 26th March 2010, 12:47

Originally Posted by bogan

and when it would eventually start, how did it run, missing anywhere?

I was actually surprised at how smooth the engine was, the throttle was responsive and the idle purred away like a contented kitten when it had warmed up a bit...

**magicmonkey** · 26th March 2010, 12:50

Originally Posted by MSTRS

It is possible that the float height is not variable. A lot of Jappers have the float and the fitting for the shutoff needle molded all in one.
As for the rest of the post...there is a lesson in there. DO NOT FUCK WITH 2 different critical things at the same time. 'Fix' one...check...'fix' second if necessary.

heh, I solve problems with complicated things for a living, it's something I know already and really shouldn't have forgotten! Still, some days i'm a complete moron and that day was one of them!

Fortunately the floats are variable, I'll probably be posting a tirade about how crap they are later as it's going to be a tedious job if the do need adjusting (check level, drain petrol, remove bowl, adjust float, fit float, fit bowl, check level, repeat ad infinitum!)

**magicmonkey** · 26th March 2010, 12:52

Originally Posted by scumdog

Hmm, you've got good spark, it APPEARS you have fuel getting to the motor - however you take the plugs out after a wiz-wiz-wiz session with the starter motor do they look at all wet/smell strongly of fuel?

Cos if not it's likely that no/not enough fuel is getting into the motor.

And I cannot recall if you mentioned it but how old is the fuel?

Fuel is about a week old so that shouldn't be a problem, I also made sure to drain any old petrol out of the carbs and the tank before putting the new stuff in (installed an in-line filter too, just to be on the safe side)

I think you're probably right about the fuel getting to the engine, I'm just buggered if I know why it isn't getting there!

**MSTRS:Me** · 26th March 2010, 13:01

When you installed that filter, did you...
Check it was round the right way.
Ensure the out end was lower than the in end.
Cut enough of the fuel line away so as to not end up with a kink, or an airlock-creating loop.

**neels** · 26th March 2010, 13:09

Originally Posted by MSTRS

When you installed that filter, did you...
Check it was round the right way.

Funny, I was just thinking the same thing, don't some have a non return valve?

Take the hose off the carbs, turn the tap to prime a see if any fuel comes out.

Originally Posted by magicmonkey

Fortunately the floats are variable, I'll probably be posting a tirade about how crap they are later as it's going to be a tedious job if the do need adjusting (check level, drain petrol, remove bowl, adjust float, fit float, fit bowl, check level, repeat ad infinitum!)

To check the float level usually I just turn the carb upside down and measure, does that not work on your carbs?

**magicmonkey** · 26th March 2010, 13:11

Originally Posted by MSTRS

When you installed that filter, did you...
Check it was round the right way.
Ensure the out end was lower than the in end.
Cut enough of the fuel line away so as to not end up with a kink, or an airlock-creating loop.

I did indeed, I checked the fuel flow through it by putting the fuel hose into a plastic bottle and making sure it would flow freely as well. The carb bowls are also plenty full so I can be sure that the filter isn't causing the issue (I think:s)

**bogan** · 26th March 2010, 13:14

Originally Posted by magicmonkey

I was actually surprised at how smooth the engine was, the throttle was responsive and the idle purred away like a contented kitten when it had warmed up a bit...

ok, so it must be work done since, ie fuel filter, o-rings or reassembly error right?

Easy to check if fuel is getting to bowls, just open drain on then and put it on prime, should get a decent flow, not just a trickle, never mind, just saw you checked that.

**kwaka_crasher** · 26th March 2010, 17:42

Originally Posted by neels

To check the float level usually I just turn the carb upside down and measure, does that not work on your carbs?

I suggest you don't completely invert them but just turn them just beyond the point that the float is resting against the valve on it's seat, otherwise the weight of the float itself can have a surprising effect on the position.

**T.W.R** · 26th March 2010, 18:55

Originally Posted by kwaka_crasher

I suggest you don't completely invert them but just turn them just beyond the point that the float is resting against the valve on it's seat, otherwise the weight of the float itself can have a surprising effect on the position.

Contrary to what factory workshop & aftermaket manuals say huh?

**magicmonkey** · 27th March 2010, 11:55

right, I'm now 99% sure that the spark isn't causing the problem, I've completely been over the wiring and checked the gaps, cleaned the plugs and checked how far the spark will jump on each cylinder, spraying some start ya bastard in each cylinder got a tiny sound of the cylinders firing as well so I think I'm as sure as I can be that it's the carbs causing the problem. Now I just need to work out where they're causing the problem, doh!!!