Help with suzuki df6a

Bikerguy

Hi guys..i have df6a that refuse to go in high revs....

Starts as champ and runn good untill you reach half throttle...then it doesnt wanna go....

Fuel system... cleaned.. replaced carburetor for new... tried external tank... i am gutted...good weather coming and i am out of water...

See videos of it running with the issue...it happen while i was on water...engine died and didnt wanna start for a while...then it did but refused to go full throttle.

https://youtube.com/shorts/ospO1NB55cE?feature=share

https://youtube.com/shorts/rx2qtw6IMxI?feature=share

fergal.b

Could be suckling in air somewhere along the fuel line check all your connections also check the vent screw on the tank is open. You could also use a large syringe connected to the nearest bit of pipe to the carb,start it up and give it a gentle squeeze to see if it helps this will tell you if the problem is between the carb and the tank.

Bikerguy

https://www.boards.ie/discussion/comment/119043850#Comment_119043850

Thank you....i was advised that you are the man....

1. Tried external tank which use different hose all together.. to no avail.

2. Replaced the fuel tank filter as well and tried engine with open cap....to no avail

3. Tried running the engine with fuel off etc but again no difference.

4. Choke or no choke it does t affect it...

5. Purchased 2 brand new factory spark plugs just to be sure. The spark plug has the right colour so the engine isnt running rich or lean...

If you listen closely it sounds like slight metalic rattle.... like restriction.... but the garage insist the valves are not moved and i checked compresion myself and its withint the limits...92psi solid... factory advice between 58-102 as per manual.

As i mentioned new carb went into it but still nothing....

Engine starts first pull and runns great but only bellow half throttle

..i wonder could it be damaged somewhere internally or something that can cause this?

Thank you very much for your respond.

fergal.b

Maybe try cleaning the jets with a bit of stiff fishing line and run some carb cleaner trough it, check the float needle I know you said its new but there might be a tinny bit of dirt floating around it doesn't take much to block them also if you have a fuel tap check that they have a rubber grommet that can break up. Im more a two stroke man than a 4 stroke so not up to date with them I am still stuck in the 80's and before 😀 I did read somewhere that Suzuki recommend running the engine on tickover for 5 min's before adding any load might be worth a go.

Bikerguy

20220509_180132.jpg

Thank you....i have 1977 johnson 6hp 2 stroke.... with fuel ratio issue as well...cant get it run right...the bleeding air fuel ratio is way off....i cleaned the carb and purchased new kit and since then it wont run well....the nozzle is off and i cant find the right way... its way too rich....

Thank you for your effort and imput

If i find out more i would keep this topic updated.

Thanks

Bikerguy

And i dont have the suzuki at hand...its sitting in service being looked after....but its 2 weeks now and i am getring nowhere with them and i am running out of patience

Ubbquittious

See will it run off a drum of gas. I did this before with a few different engines to rule out carb problems. If you have one of these (https://www.maceoinltd.com/high-pressure-jumbo-regulator/) you can adjust the flow nicely and all you need then is something to hold the hose infront of the intake valve temporarily

Bikerguy

So engine came out of service....suzuki authorized dealer... they fitted rpm counter....and when engine shutter its on 6000rpm where there is factory rev limiter. So engine is reving 6000 tops and starts cutting....

According to them there is nothing wrong....according to me it never done before....but they know more....so i have the engine back.... the rpm counter indicates 6k rpm and starts limiting revs.....just dont understand why half throttle....so i guess thats me sorted....

They checked all...valves....head...gears...all clear and said the engine is sweet as butter.

Mick Tator

Butter is salty, not sweet! I don't know that engine I'd be guided more by the sound of the engine and the RPM counter reading than by the throttle position or anything the vendor told me There are stories elsewhere online about valves sticking on that engine

Bikerguy

https://www.boards.ie/discussion/comment/119078733#Comment_119078733

There are....but that will cause the engine not start and ussually occur while engine was disposed to salt water and was parked for few weeks right after...i just purchased the rpm reader/tacho and it does not shutter unless you hit redline aka 6k rpm.....which make sense...thank you