I have tried setting the carbs up as per the book but I am having trouble ,
She will run and rev fine but tick over is another thing, anything below 1500 rpm she shakes like a Harley and the carbs vibrate and bounce on the rubbers.
HELP and or ADVICE needed ......AGAIN!
ROUGH TICK OVER GT380
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barney01
- Posts: 3181
- Joined: Wed Sep 26, 2012 7:33 pm
- Location: Prestatyn.Wales
Re: ROUGH TICK OVER GT380
Hi. The tickover is controlled by the pilot air screw and the pilot jet. The pilot jet passage also needs to be clean too. Make sure all the throttle valves are synchronised as well. Here is a link to the carb manual to help.
https://www.3cyl.com/mraxl/gt/manuals/s ... /cover.htm
The engine must be warmed up before adjustments are made
https://www.3cyl.com/mraxl/gt/manuals/s ... /cover.htm
The engine must be warmed up before adjustments are made
NO SMOKE .......NO POKE
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arthur
- Posts: 180
- Joined: Wed Jun 17, 2020 8:55 pm
Re: ROUGH TICK OVER GT380
Hi Barney,
Thanks for your input once again I am in your debt!
I am pretty sure the slides are in sync, I have used the spacer /drill underneath each one method then watched as the cable pulled them up .
I will try blowing out the pilot jets and air screws see if it helps.
I did wonder if it may be timing related but she seems to go ok and I am loath to mess it up by fiddling
(Although isn't that what winter afternoons for?)
Thanks for your input once again I am in your debt!
I am pretty sure the slides are in sync, I have used the spacer /drill underneath each one method then watched as the cable pulled them up .
I will try blowing out the pilot jets and air screws see if it helps.
I did wonder if it may be timing related but she seems to go ok and I am loath to mess it up by fiddling
(Although isn't that what winter afternoons for?)
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barney01
- Posts: 3181
- Joined: Wed Sep 26, 2012 7:33 pm
- Location: Prestatyn.Wales
Re: ROUGH TICK OVER GT380
I have attached a screenshot from Klemn vintage about tuning for idling. This may also help
- Attachments
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- Screenshot_20241022-180243.png (208.12 KiB) Viewed 2430 times
NO SMOKE .......NO POKE
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arthur
- Posts: 180
- Joined: Wed Jun 17, 2020 8:55 pm
Re: ROUGH TICK OVER GT380
That's interesting reading.
On the up side I took the carbs off this afternoon to check thing over , the middle pilot jet was blocked but a winkle with a bit of wire and the air line sorted it out. I can't think where the muck came from she's got a in line filter fitted
I cleaned the other two whilst I was at it all back together now.
Getting good at this now 2 1/2 hours from putting her on the lift to rolling her out the door, its to dark and cold to start her tonight .
Tomorrow 's another day
On the up side I took the carbs off this afternoon to check thing over , the middle pilot jet was blocked but a winkle with a bit of wire and the air line sorted it out. I can't think where the muck came from she's got a in line filter fitted
I cleaned the other two whilst I was at it all back together now.
Getting good at this now 2 1/2 hours from putting her on the lift to rolling her out the door, its to dark and cold to start her tonight .
Tomorrow 's another day
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barney01
- Posts: 3181
- Joined: Wed Sep 26, 2012 7:33 pm
- Location: Prestatyn.Wales
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arthur
- Posts: 180
- Joined: Wed Jun 17, 2020 8:55 pm
Re: ROUGH TICK OVER GT380
May noy be connected BUT!
I had a go at retiming her using a strobe
Left on the line
centre on the line
right hand side just before
However there is not enough adjustment left on the back plate to pull them into spec
I have tried slotting the back plate but it wont go far enough left and the points mounting plate hits the retaining screw ?
I had a go at retiming her using a strobe
Left on the line
centre on the line
right hand side just before
However there is not enough adjustment left on the back plate to pull them into spec
I have tried slotting the back plate but it wont go far enough left and the points mounting plate hits the retaining screw ?
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arthur
- Posts: 180
- Joined: Wed Jun 17, 2020 8:55 pm
Re: ROUGH TICK OVER GT380
So revisited it today, took it apart put it together again /again everything lines up ... go figure ?
took her out for a spin, goes like hot snot! Well warm mucus anyway
but still leaking oil like the Exxon Valdez! OH JOY.
took her out for a spin, goes like hot snot! Well warm mucus anyway
but still leaking oil like the Exxon Valdez! OH JOY.-
barney01
- Posts: 3181
- Joined: Wed Sep 26, 2012 7:33 pm
- Location: Prestatyn.Wales
Re: ROUGH TICK OVER GT380
Are you sure the oil is coming from the banjo's? These plastic oil feed pipes are prone to hairline splits that are difficult to see. The oil runs down the outside of the tube and appears to come from the banjo.
NO SMOKE .......NO POKE
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arthur
- Posts: 180
- Joined: Wed Jun 17, 2020 8:55 pm
Re: ROUGH TICK OVER GT380
Hi Barney ,
I am pretty sure the banjos are the problem. I did the" fill the lines and hang them up overnight test" and not a drop was spilt.
BUT maybe the split only opens up under pressure of the pump or perhaps the heat of the engine I only ask as it seems to get worse the more I push on .
I am pretty sure the banjos are the problem. I did the" fill the lines and hang them up overnight test" and not a drop was spilt.
BUT maybe the split only opens up under pressure of the pump or perhaps the heat of the engine I only ask as it seems to get worse the more I push on .