Frustrating problem with os 50, Please help

[raptorist]

I have a raptor 50 v1. Due to lack of time it is still virtually unflown despite it being purchased over 2 years ago. I have a quick uk header tank and a filter in the fuel line just before the carb. The engine starts and seems to run fine for approxtimatly 5 mins it will rev up perfectly for this time. Then it stop's, dead. no popping and no miss firing just stops. it will start immediatly after and then runs fine for 5 mins again. i've changed the plug(os no 8 ) and checked all the fuel lines. any ideas??

p.s coolpower 10% fuel is used although its 12 months old if it makes a difference.

[Raptorite]

Hi Raptorist,

I have seen this problem myself in the past, it sounds to me like the fuel you are using has degraded due to age.

Try a fresh gallon of fuel and see how that goes, if all goes well I would suggest you buy 2 or more extra gallons and mix your existing fuel with the fresh stuff about 50 - 50 this will revive your existing fuel so you dont just loose it.

I hope this helps.

Cheers,

Pete.

[raptorist]

Frustrating problem with os 50, Please help

Thanks for the reply Pete. I'll try it A.S.A.P

cheers again
Chris

[Raptorite]

No problem Chris.

Let us know how you get on.

Cheers,

Pete.

[raptorist]

Still Struggling

Ok, Just tried some brand new fuel(coolpower 10% again), and it's still doing the same thing. It started raining so I didn't have time to try other thing's. Back to basics then, I'll try to explain how my tanks are piped up just to make sure I've got it right.

Working back from the carb:

Between the carb and the Klunk line in the header tank i have a fuel filter(is there a correct way round for this to be fit??). Then from the header tank I have a line to the Klunk line in the main tank. The other line from the main tank goes to the exhaust. There is another outlet from the header tank which is blanked of during running and I use for filling the system.

Hope this makes sense.

I have set up the engine needles as best I can according to "Ray's". It has not run correctly since I fitted the header tank approxtimatly six month's ago after a crash.

Short of any other ideas I'm just on with changing the fuel lines to cut out the header tank hopefully this will lead me in one direction or another.

Cheer's for reading this and for any ideas..

Chris

[Stuart]

How many turns have you set on the carb ? - from memory this should be about 2 turns factory set and the idle needle what is that setting ?

Whats the position of the header tank in relation to the carb, ideally the center spot of the header tank should sit dead center on the carb. If lower this will run a lean engine, if higher it will push fuel into the carb and run a richer engine.

Also as a test by pass the header and move your filter onto the line from the main tank then add a new line from the filter onto the carb, lets see if this resolves the issue.

[turkuss]

hi just a idea but i had a problem just the same on a motor bike of mine.
it sounds like a vacume is being built up in the tank that starves the carb of fuel and when the engine has stopped the air is let back in to the tank thro the carb. witch in turn lets you start and run the engine untill the vacume builds up again.
just my two pennys worth hope it helps.

alan

[raptorist]

The Needle is set at just shy of two turns out, and the idle needle is set a hairs width to the lean side. I can't get to try cutting out the header til weekend. Thanks alot.

As for the vacuum suggestion i think the pipe from the exhaust is to push the fuel through to the carb, unless there's a problem with that? Another angle and another idea cheers Alan

thanks again i'll update you as soon as i can.

Cheers Chris

[Stuart]

Just another thought, if you have a small leak from the exhaust to the main tank when you push up the throttle this will kill your engine by leaning it with the lack of pressure going into the tank.....check the line and when the engine is running at idle look to see if the pressure nipple is not loose or has any leaking around it......Also you are using as gasket between the engine and the muffler ?

The muffler flange is flat and sitting perfectly against the engine exhaust, it hasn't been damaged and and slightly bent at either end.....any loss of pressure will create engine leaning.