My engine loses its acceleration a few mins in when running

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eddie2166

eddie2166

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i have a wt 668 on my cy 23cc, when i start it up the acceleration is really fast and usually gets a wheelie going. however 2 mins in the engine starts off kinda slurpy then after the revs built up it then goes like a bat out of hell

would the solution be to get the wt 813 carb with a built in accn pump?
 
eddie2166 said:
i have a wt 668 on my cy 23cc, when i start it up the acceleration is really fast and usually gets a wheelie going. however 2 mins in the engine starts off kinda slurpy then after the revs built up it then goes like a bat out of hell

would the solution be to get the wt 813 carb with a built in accn pump?
Click to expand...

Probably just needs a tune up mate. Difficult to tell without seeing it but 2mins in the engine will be fully warmed up so it might be a bit rich on the low speed needle if its running ok when cold (sort of giving the effect of a choke on an old car). Turning the L needle anti clockwise will lean it out but only turn it 1/16th of a turn at a time so you don't miss the sweet spot. Keep giving it a run to try it after each adjustment until it comes good. If it goes obviously worse then you need to be turning clockwise in small increments again til you find the G spot :w00t:
 
eddie2166 said:
i have a wt 668 on my cy 23cc, when i start it up the acceleration is really fast and usually gets a wheelie going. however 2 mins in the engine starts off kinda slurpy then after the revs built up it then goes like a bat out of hell

would the solution be to get the wt 813 carb with a built in accn pump?
Click to expand...

What are you running?
1/6 FG Baja, Marder, MT; 1/5 On-Road (v. unusual to see one of them wheelying !!!); HPI 5 / Clone; Losi 5ive? ; Hurrax? ; Hoermann? .......

+1 reset to factory and tune.
Check other posts for tuning, plug colours, Carb adjustment - very straightforward .. once done, shouldn't have to touch it for ages, unlike nitro ..

Al.
 
the weird thing is that immediately when is start the engine it has so much accn it does wheelies but after a short time it bogs down a bit and doesn't have the kick it used to have, im thinking it cant be the needle settings because if it was, it wouldn't accelerate well at any given point. therefore i think it may be because the carb its self doesn't have an accelerator pump

just need a second opinion
 
It takes a few minutes to warm up fully just like your 1:1 engine. On old 1:1 cars you had to start them with a manual choke when cold then gradually ease it in as the engine warmed up or if the choke was left open when the engine was warm it would run too rich and perform like a bag of spanners esp at low rpm when trying to pick up. I reckon it is a similar scenario here and the mixture is too rich when the engine is warm hence it struggling to pick up cos there is too much fuel. Once it picks up it is burning at a quicker rate so will cope with the little extra fuel in the rich mixture. Just my opinion of course :D
 
dwarfy said:
It takes a few minutes to warm up fully just like your 1:1 engine. On old 1:1 cars you had to start them with a manual choke when cold then gradually ease it in as the engine warmed up or if the choke was left open when the engine was warm it would run too rich and perform like a bag of spanners esp at low rpm when trying to pick up. I reckon it is a similar scenario here and the mixture is too rich when the engine is warm hence it struggling to pick up cos there is too much fuel. Once it picks up it is burning at a quicker rate so will cope with the little extra fuel in the rich mixture. Just my opinion of course :D
Click to expand...

lol yes thanks for the opinion, i just spoke to someone and they said its probably going to be the high speed needle cos the low speed picks up fine, its when u need the extra umph from the engine to carry the accn on which is when it switches over the high speed jet. When its warming up as u said it needs more fuel to warm it up but once its warm it needs less, so hopefully tomorrow im guna mess around with the hsn with little increments to see how it goes
 
In your 1st post you said it starts off slurpy then goes like a bat out of hell once the revs have picked up so I took it as struggling from a stand still and not once the H needle had kicked in. The high speed needle kicks in at about 1/3 throttle but if it was running a tad lean on the H needle i would have thought you would experience problems from the off and not it running fine from cold then stuttering when it has warmed up.

Have a look at the tuning guide sticky & use it for reference & Im sure you will get it sorted in no time.
 
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i had wot sounds like the same problem with my marder. it would run well for a few minutes then bog down on the low end. It turn out to be the clutch spring. Worked fine when cold but as it warmed up it would start to drag causing the engine to bog down in low revs
 
or could be starvation of fuel, when running not enough being pumped to the carb, so it will run ok until the primer bubble emptys.. do you see fuel in the bubble after its stalled?

if not, then thats defo the prob, check fuel lines for any leaks etc.

If primer bulb is full..then can be a number of things like those above have already posted..let the elimination process begin!
 
try a new spark plug fresh gas an tune your carb ******new carb an if you can try bying a compreashin tester $30 might be the rings piston it could be a week spark check your fly wheel make sher thers no rust an check the gab ext it could even be bearings once they heat up they exspand an sees up
 
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