2 Stroke Help Needed

[les g]

as title TJ,s bike is rebuilt and on the road but........
the revs are are a bit slow to pick up initially then it really whizzs
also when the throttle is blipped the revs dont immediately settle to idle they sort of sit at 2500 for a second or two then come down to 1500 as per the manual
any ideas
cheers les g

[HandyAndy]

as title TJ,s bike is rebuilt and on the road but........
the revs are are a bit slow to pick up initially then it really whizzs
also when the throttle is blipped the revs dont immediately settle to idle they sort of sit at 2500 for a second or two then come down to 1500 as per the manual
any ideas
cheers les g
you,ve either got crud in the float bowl(s) or a split in the carb rubber, or the float has a hole in it( ie flooded float ) what bike is it?
andy

[les g]

It is a 1999 Suzuki TS50X Andy

Cheers TJ

[HandyAndy]

i had the road version ( X1, 50cc ) when i was 16.
having thought about your description of what its doing in my opinion its got to be the carb/carb related.
a few ideas......
as i previously posted
someone has changed the jets or mixture setting on the carb ( young uns do this to try to make it faster)
one other thing, take plug out, is it covered in oily substance( it,ll be two stroke oil) if so then its the mixture , been fiddled with.
or an air leak in the carb rubber, as you say its slow to pick up so its got too much air to fuel ratio,
should be easy fix, as a cheap test, take carb rubber off & wrap insulation tape around it, put back on engine, if prob still there then you know its not the rubber, but don,t leave tape on, replace with new rubber, as its 10 yrs old its probably aged & perished.
hope this helps.
bikes i,m happy with, cvh engines :eek: :confused: :o :D
andy

[les g]

This is why father is not very good with two stroke engines, 6.1 litre turbo charged, , intercooled and aftercooled diesel engine.
http://i250.photobucket.com/albums/gg248/04goodto/61litreengine001.jpg

Just one of his projects and little toys. (no that isnt him in the picture)

Cheers TJ

[jasongray5]

Definately sounds like perished carb rubbers to me...
Andy, More cars should be 2 stroke...

[HandyAndy]

Hi TJ, is what i,ve suggested as poss reasons for your bike playing up make sense to you then?
i,ve spent 30 yrs around two stroke bikes, owning/riding & racing them at semi pro level & a 2 stroke engine is quite straight forward, alot easier than 4 stroke in my opinion.
hope the suggestions i made help out in some way.
cheers
andy

[HandyAndy]

Definately sounds like perished carb rubbers to me...
Andy, More cars should be 2 stroke...
Jase,
give me a 2 stroke engine anyday & i,ll have it screaming like a pig on hot coals, my mis spent youth & all that , plus the racing background, we used to get 98bhp from a 250cc 2 stroke motor, in a bike that weighed 88 kgs :eek:
talk about quick :D :D
andy

[jasongray5]

Being dragged up on a farm meant lots of open fields and woods to thrash around on! Was on a 250 kwak when I was about 12:eek:
The new thing at the moment for us is 50cc mini motos!!!
Taken to bits and put back together tooo many times!! Just soo simple to work on and if you totaly bin one, ah well!!
Would love to make the first 2 stroke roadster though, although i feel problems might come at IVA regarding noise and emmissions... Bad times!

[Bonzo]

This is why farther is not very good with two stroke engines, 6.1 litre turbo charged, super charged, intercooled and aftercooled diesel engine.
http://i250.photobucket.com/albums/gg248/04goodto/61litreengine001.jpg

Just one of his projects and little toys. (no that isnt him in the picture)

Cheers TJ

Hi TJ

Tell your dad I could do with that engine for my mates boat :D

It'll make mincemeat out of his Iveco 320 BHP unit :D :D

[jasongray5]

98bhp from a 250cc



Could only be 2 stroke!!!

[les g]

cheers andy
the carb is bolted to the barrel (new gaskets and clean faces ) and not rubbers like on our roadster
you almost think the slide is sticking do you think the reeds have gone weak ?
the bike really goes well and starts first or second kick
dad has gone for a beer to think about this one
thanks TJ

[HandyAndy]

cheers andy
the carb is bolted to the barrel (new gaskets and clean faces ) and not rubbers like on our roadster
you almost think the slide is sticking do you think the reeds have gone weak ?
the bike really goes well and starts first or second kick
dad has gone for a beer to think about this one
thanks TJ
right, as carb is bolted direct to barrel then yes it sounds like you have reed either sticking or at a different angle to the other reed, with the symptoms you describe it is definitly air / fuel prob, too much air & not enough fuel until the engine overcomes the prob at a higher revs, i,d also say that as when you shut off throttle there is too much fuel to air ratio & thats why it doesn,t settle to the correct revs straight away, its got more fuel to burn before it settles, regardless of the throttle position, i reckon when its been rebuilt someone has set the carb up wrong.
andy

[les g]

Hi TJ

Tell your dad I could do with that engine for my mates boat :D

It'll make mincemeat out of his Iveco 320 BHP unit :D :D

yes Ronnie you are right dad built a pair of these :D
they went in a 38 ft aquastar .....yep and it went like fook
cheers TJ

[HandyAndy]

Could only be 2 stroke!!!
yep, it was an Aprillia GP 250 bike which uses a suzuki rgv motor thats been tweeked :cool: this wasn,t a road bike made into a race bike, it was a full works GP bike.
what power to weight ratio is that then? 98bhp on a bike weighing 88kgs without fuel or rider? it was bloody quick when you hit the power band.
andy

[ACE HIGH]

Retired chainsaw dealer,30 years experience so I will pretend its a chainsaw or brushcutter! I will guess that the low speed mixture is too lean,at the bottom 25% of the Rev range,or the next 25% or both,but most likely the lower range.If the bike has a tendency to really scream to the top end of the rev range sounding perfect like a grand prix racer then maybe the whole mixture is too lean,two strokes go better when they just 4 stroke without load at the max revs.:)look also for any air leaks including under the cylinder barrel.The rev problem when you throttle off is probably a sticking cable set a little too tight,slacken it off,or a bend in the cable,ie the spring wont push/seat the slide at the lower end of its travel,a common weed trimmer problem.:) David

[ACE HIGH]

Also check that the gap between the armature airleg and the flywheel is correct,try 12 thous if unsure and try closing the spark plug gap 5 thous.20/30 thous.Make sure the complete ignition system is spotless,no dirt and run it in the dark ,looking closely at all of the ignition,you may be surprise at what you may see.(shorting/tracking):) David I also recommend Performance Tuning in theory and practice: 2 strokes. A.Graham Bell:Haynes his 4 stroke book is also outstanding,also Haynes.

[fabbyglass]

Freshly rebuilt the motor haven't you? Did Your Dad use loadsa 2 stroke when rebuilding if so then that alters the mixture, let it idle for a while to warm up and burn it off. Sounds like sticky cable to me also is the oil pump working? I would junk that and run it pre mix as you know you are getting oil then.
Reeds could be damaged, good idea to replace them with boysen fibre reeds as lift quicker.
Sprite Bike shop has got same bike in and it goes well for a "iddycc".

Other snag might be size of your dads hands unable to hold proper spanners like 8 and 10 milly instead of 40milly minimum....:p

Tell your Dad sorry I missed his call, signal not very clever. Phone rings but when I answer the signal goes...:confused:

Off to St Eval to sit in the sun and watch sprint today...:D

[fabbyglass]

Two strokes like to be spoken to nicely and lovingly looked after then will reward you with muchly anti social neighbour annoying fun.....enjoy and **** the neighbours:D

(90odd bhp 250!!! Andy you lucky git...)

[HandyAndy]

Mark, it was like a Banshee high on castrol "R"...:D
a bugger if it bogged down but when it hit the sweet point on the revs :eek: :eek: :eek:
andy

[RAYLEE29]

Sounds like its running lean to me, what sort of age are the crank seals as they can go hard and leak and cause a lean mixture.
check idle jets.
float height.
also worth checking the static timing.
does it have reads or a disc valve as the timing on disc valves can give simlar probs.
and lastly a leak on the exhaust flange will cause a weak mixture.
Ray:)