Suzuki 2 Strokes

Someone touched on this earlier, but let's try again. Stock OEM 188 series use large round main jets. 159 series use hex main jets and they are not the same thread. 159 is the correct replacement but you must use the correct size (P4) and hex jets.

97.5 round = 110 hex
100 115 hex
102.5 120 hex

I don't believe there is a 102.5 hex, but if there was it would equate to a 92.5 - 95 round main jet

If you are using old Round jets, I would recommend changing to new Hex jets. That way you know that they are flowing the amount they are supposed to.

Check the "choke" plunger too. The end is rubber and gets hard and then leaks which makes the whole thing rich.

I stated earlier 188 are obsolete in size needed for T500/T350. Am I wrong?

I run the "other" series needle jet that is the same as the 188 but takes hex versus round. Not sure if that is the 159 series... I'll check

That table cross between round and hex is not accurate. I have used it many times, only to have to take carbs apart again. I smartened up and put the round in where hex goes no worries, mates with needle jet as it should and correct A/F first time. I have a few bikes that way for many years and many thousand of miles. Stone reliable and I am very specific thatl my jetting is spot on at every throttle position, across full RPM, good mpg, ride it hard or ride it easy and ride it many miles

If you are building a stock bike my advice is to use the round or you need the skill to know how to tell if you are jetted correctly. If you play with bikes it is a skill you should have. I don't have much extra time in life so I just want to get it perfect first try and find the next project

If you are modifying your bike, Pods. Then use Hex cross since you are expected to spend some time tuning any ways. Chambers I usually start stock jetting.

Each person can do what they want of course, I have and do both depending what I am doing. Just don't think it wise to condemn it for reason has show me backed by experience it works well and reliable. I am sure this will be countered and will let that go on this post.

I'll check to see if its the 159 is same as 188 (unless someone beats me to it)

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See the post above..

I have one on my RD400 works great now I just have figue out why the oil pump is dumping so much oil in motor going pull the pump apart see if something up.
Take care!

Before you strip the pump, are you sure it's a problem? Often a smokey exhaust is the result of slow riding and rebuilds with lots of oil. Other times it's the one way check valves leaking.

Thaqt's not to say that your pump is not a problem, but it's not usually the problem

Thanks GP wondering if the new check valves are not strong enough got a set on eBay they were crap then got some Kawi ones no leaks in lines really not looking forward to this!
Take care

I suspect that new valves will weep and some quite badly. When they are machined, the surface can never be completely square and flat. There will always be some chatter or tool vibration etc and if the gaps/bumps in the surface are larger than oil molecules, I'd expect that some will escape.

They typically seem to take a few opening and closing cycles for the ball to flatten the seat surface to get a good seal. You could probably simulate that with low pressure air puled on and off to lift the ball and let it strike the seat. 100psi compressed air will NOT work. It pushes the balls inside the springs and then they never seal.

Thanks! pulled everything apart the banjos don't leak hung them up for 2 days bench tested pump looks great,adjustment in all the way. At idle smokes just right, rev up looks good ,take on the road just dumps oil everywhere. Could the engine suck check valve balls in making for over oiling?
Brand new Kawi banjos tried after market ones they were junk.
Happy Easter!

I wonder if the crankcases and exhaust are full of oil and it just needs a good long hard blast to clean it out.

I don't believe that the oil can be sucked through the pump, but I suppose it's possible.

Well after taking everything apart, bleeding, put it all back together works perfect! Only thing I can think of is somehow the pump was all the way open maybe pinched it with bleed bolt? Not much to the pump. Thanks for the help!