Suzuki Eiger Quad jets

User00026

Well-Known Member
Gents,

My quadbike runs beautifully until it gets to about halfway up the throttle, and/or it comes under towing load, or going uphill..ie, until a certain 'pressure' is reached.

I have taken the carburetor apart and cleaned the jets, it gave a small increase in performance on the initial stage, due to cloggin in the pilot jet, but the main jet was clean.

question is, does anyone here have a slightly larger main jet I could try, or have any other ideas? My local blacksmith recently cleaned the fuel lines, tank and pump, as well as checked the fuel lines and spark plugs, which was expensive, and did nothing to fix the problem...hence I've resolved to DIY!!!

thoughts/help on the jetting front?
 

JAYB

Administrator
Site Staff
Peter,

The best I can come up with is to check out a Suzuki quad forum that will probably sort you out if no one on here can help.

John
 

teyhan1

Well-Known Member
First of all, given what you have done so far I would check the valve clearances.
Second I would check very carefully that there are no splits in your intake and that it assembled correctly.
Although you cleaned the pilot jet did you check that the pilot jet air path was free from obstruction?
Your problem sounds like a transition problem. This is when you will e taking fuel from the idle and main jet. The holes that provide fuel from the idle circuit are very small. There are often three of them with only one available a idle and the other two coming into play as the throttle butterfly is opened. You will need to get some jet cleaner and some fine jet cleaning wire and take everything off the carb to give you access to all of the airways. It may pay to drop the carb into an ultrasonic cleaner. If you don't have one your local motorbike shop will.
Finall do not be tempted to muck aout with different jets. They really are only for altitude compensation. And don't forget to change you air filter too.
 

mereside

Well-Known Member
First of all, given what you have done so far I would check the valve clearances.
Second I would check very carefully that there are no splits in your intake and that it assembled correctly.
Although you cleaned the pilot jet did you check that the pilot jet air path was free from obstruction?
Your problem sounds like a transition problem. This is when you will e taking fuel from the idle and main jet. The holes that provide fuel from the idle circuit are very small. There are often three of them with only one available a idle and the other two coming into play as the throttle butterfly is opened. You will need to get some jet cleaner and some fine jet cleaning wire and take everything off the carb to give you access to all of the airways. It may pay to drop the carb into an ultrasonic cleaner. If you don't have one your local motorbike shop will.
Finall do not be tempted to muck aout with different jets. They really are only for altitude compensation. And don't forget to change you air filter too.

I agree with this post , just take out the main jet then remove the emultion tubes underneath and clean properly after everything has been done you could if not cured try dropping the needle one clip if these are adjustable. just to clarify what is it doing is it bogging down with too much fuel or running lean?
dropping a needle will lean off the mixture mid to top throttle and raising gives more fuel hope this helps
also to check how it is running properly you would need to run the quad and at the point you want to check whats going on kill the engine and remove the plug and inspect you must kill it at the procise moment you want to find out whats going on dont back off the throttle. this is a poor mans dyno ,atb wayne
 

Hornet 6

Well-Known Member
Plug checks are pretty much pointless on anything running on unleaded petrol.
If it used to run ok, and nothing has been modified I would be looking at air leaks, and giving the carb a proper clean.
Ultra sonic bath and a high pressure air-line will shift most dirt, try to refrain from poking bits of wire etc through jets and internal drillings.
Jets can be readily obtained from a decent M/bike shops, or on line from somebody like Allens Performance Mikuni Keihin Carbs

Neil. :)
 

Yorric

Well-Known Member
Rough running under load could be down to ignition system breakdown (higher cylinder pressure makes the sparking more difficult & this feeds back into the electrix resulting in loosing the spark intensity). Change the plug, check the plug lead, clean off any crud round the coil all may help. If this fails, then you may need to swap the coil or igniter unit.
I had your symptoms on a few of my bikes & it was ignition not fuel in every case.

​Ian
 

mereside

Well-Known Member
Plug checks are pretty much pointless on anything running on unleaded petrol.
If it used to run ok, and nothing has been modified I would be looking at air leaks, and giving the carb a proper clean.
Ultra sonic bath and a high pressure air-line will shift most dirt, try to refrain from poking bits of wire etc through jets and internal drillings.
Jets can be readily obtained from a decent M/bike shops, or on line from somebody like Allens Performance Mikuni Keihin Carbs

Neil. :)

Neil thats rubbish plug chops are invaluable if done correctly and have used this method for over 20 years and one thing i do know about is jetting on carbs running race bikes if the jetting was one jet off you might as well have gone home. This method works on all petrol from unleaded to elf gas its no good doing lots of different things at once to solve a problem as you dont learn whats wrong change one thing and move on the problem could be lots of things as the symtoms are all similar to each other from a stator breaking down to incorrect jetting you just have to check methodically to find the fault,atb wayne. ps if having a full service before and it still has not cured you should be able to rule out plugs as these would have been changed but as its the simplist and easiest thing to change start there , atb wayne
 

shortshot

Well-Known Member
I have an Eiger that farts and hesitates in reverse, runs fine forward but feels like fuel starved in reverse so I blame the automatic transmission! So I live with it. Also has delayed pop after you switch off and dismount! Still a good bike and pulls well with trailer.
 

VSS

Well-Known Member
My old quad was just like that, and it was mostly due to crud from the tank coming through and blocking the carb.
After draining and cleaning the tank and the carb to the best of my ability I fitted an in-line fuel filter it was ok for a good while. Just had to clean out the filter from time to time.
 

joe soapy

Well-Known Member
I have an Eiger that farts and hesitates in reverse, runs fine forward but feels like fuel starved in reverse so I blame the automatic transmission! So I live with it. Also has delayed pop after you switch off and dismount! Still a good bike and pulls well with trailer.


Thats a saftey feature to prevent the driver from killing himself, yamaha are the same
 

blaven

Well-Known Member
Just a thought and probably wrong, but does the silencer have a spark arrestor which is removeable for cleaning?
 

Hornet 6

Well-Known Member
Neil thats rubbish plug chops are invaluable if done correctly

You carry on then, I know from years of trying that it is not an accurate method with modern fuels.
Back in the 70's it worked, and I successfully used it on many bikes, these days it may get you close (ish), but not as close as an air fuel meter.
when I was last into my bikes I used one of these FAST 170501 FAST Wide Band Digital Air/Fuel Meters

Neil. :)
 
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