Kawi2strokes.com Forum

Keeps gettin better.

Today I swapped out the pilot to a 35. Instantly the blurble just off idle was gone. It's getting very smooth now. Still gotta some hesitation when you put your foot in it. I've got 2 over and under on the stock needle coming from Sudco and trading out some jets at the shop tomorrow. I'm getting close.

Motor seems to have settled in a bit now. Hit 7-8k a few times and sounds good. No noise, nice and quiet like it should. Looks like I poulled a bonehead move a couple days ago as I noticed today the right side has two head gaskets on it. I'll be removing that tomorrow.

I'm hoping to finally get all the ram air components on it next week. That'll be final assembly and it will be road worthy. I know a 650 that's gonna get a surprise this year when I see him.

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74 H2B with reeds and 34mm carbs
75 S3A Ram Air with reeds and 30mm carbs
73 S2A (wife's bike)
71 Yammi RT1B
83 HD Sportster
03 Yammi R1
06 Kaw 750 Vulcan (wife’s bike)
12 Yammi vstar 250 (wife’s bike)

Yesterday I decided I needed to get in there and clean the baffles out. No wonder they sounded like stingers. Whoever did these pipes packed them FULL of insulation, so tight that they wouldn't move. No wire of course and it expanded in there tight. Burned them out, picked all the carbon off, repacked and loaded them up. Way quieter now.

Oh and one thing I learned. Don't swat hot baffles against wood trying to knock the carbon out. A piece might fly loose, go down the inside of your shirt and burn you.





Today will be the first day riding it with the ram air connected. The jetting pretty close. I still gotta throw a richer needle in it but it's road worthy enough for a ride. I'm waiting to put the carb boot clamps on in case I gotta change a main after working the needle. It's a little dirty but will clean it up once the carbs are completed. Gum cutter will clean that right up.











Think the neighbor is tired of me burning up his driveway on the way out?

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74 H2B with reeds and 34mm carbs
75 S3A Ram Air with reeds and 30mm carbs
73 S2A (wife's bike)
71 Yammi RT1B
83 HD Sportster
03 Yammi R1
06 Kaw 750 Vulcan (wife’s bike)
12 Yammi vstar 250 (wife’s bike)

I've been riding this a bit now.

New needles showed up yesterday and should have this mid range issue cleared up very soon. The bike has a nice stock band till around 6 then gets its act together real good after that. I did notice a little noise in the left cylinder around 3k with a little throttle on one ride, once over 4k it went away, sounded like deto so decided to investigate. Found the cylinders were at 175psi so I ported it a little to get it to 165. Seems very happy there. Noise in the left cylinder is gone. This could have been due to carb leaning on the needle as well but we'll get the needle and jets right and try again. Timing was spot on so don't think it had anything to do with that. Once the jetting is right, I'm going to run it as is till after the gap then play with the cylinders again. I still can move them down to bring the compression back up if need be. pistons look great, no obvious signs of damage or holing so I must be close on the jetting. Little rich on idle but I think the stock needle is causing some of that because of where I have it set at. Rolls good at 70, no stumble, nice clean run at that rpm, plenty of power on standby.

More to come. So far I am very pleased with its results.

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74 H2B with reeds and 34mm carbs
75 S3A Ram Air with reeds and 30mm carbs
73 S2A (wife's bike)
71 Yammi RT1B
83 HD Sportster
03 Yammi R1
06 Kaw 750 Vulcan (wife’s bike)
12 Yammi vstar 250 (wife’s bike)

Richard, what are the odds of you posting a video??? I would love to see and hear it...

Ah.......I'll get something posted by the weekend. I'll see if I can get it to do one of those roll on wheelies it did the other day. That sure surpised me the other day and this thing has a 15 tooth on the front.

I have my helmet cam getting it geared up for the gap. I'll take it out this weekend and get some fun posted. Once I get the needle and jetting established, I'll post up what I did to this critter to get it to where it is.

Are you thinking of modding up your S3? That little motor has lots of potential that seems tuned out by kaw.

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74 H2B with reeds and 34mm carbs
75 S3A Ram Air with reeds and 30mm carbs
73 S2A (wife's bike)
71 Yammi RT1B
83 HD Sportster
03 Yammi R1
06 Kaw 750 Vulcan (wife’s bike)
12 Yammi vstar 250 (wife’s bike)

Be careful Richad,

Even at 165 that is a lot of compression. 92 octane is only good for stock compression. And detonation can be light enough not to hear, and you can hole a piston without even knowing untill you lose power.

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Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........

I've been keeping my good eye on the pistons, cylinders, plugs, heads, you name it and all looks very good. The engine has been apart 3 times in 30 miles. I was waiting till the needles showed up to really work the engine a bit hard, they got here yesterday, put one stage rich in today. Haven't ran it yet. What amazed me was the motor got tighter after the first couple heat cycles. I could tell every time I went to start it. I had no idea it was that high till I started hearing the noise, it was so faint I couldn't hardly hear it. Everything was checking out great except for the carb mid range was a little lean. I figured the lean condition may have been contributing but I'm not ruling anything out just yet. I know the compression is up there but the stock bike ran 150, there should be some sort of safety factor built in, just how much is yet to be known on this engine.

Alot of the cylinder characteristics have been rearranged with the tighter squish, raised tranfers and exhaust, reeds, added boost ports, are those should be contributing to a cleaner evac of the cylinder so the hot gases and spots may not be as prevalent on the crown and chamber as in say, an original squish engine. The exhaust pulse is very strong, better than the stock bike for sure so I can only assume more air is running thourgh the block. Engine heat causing deto during the summer is a concern. A extra head gasket shaves off 10lbs so if I have to, I'll raise the exhaust port some more to bring it down. I'm being as thorough on this build as possible as I want this to succeed rather than fail when I don't expect it to.

I wish we was sitting at the gap so we could talk about compression, squish, porting and the like. I've dealt with quite a few 2 stroke dirt bikes since I was a kid. I'm real interested in what is capable on the 'dog' of the triple lineup and a good tuner would be a wealth of information.

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74 H2B with reeds and 34mm carbs
75 S3A Ram Air with reeds and 30mm carbs
73 S2A (wife's bike)
71 Yammi RT1B
83 HD Sportster
03 Yammi R1
06 Kaw 750 Vulcan (wife’s bike)
12 Yammi vstar 250 (wife’s bike)

I'm looking forward to a video too!

Is the 165psi for triple motors? I checked compression on my ktm after having the head modded and I was up to around 215psi and run with no problems on 93 pump gas. I know on some of the other boards I read about psi numbers and octane people say the max for pump is way lower than what I have. Is the lower number for older air-cooled bikes, or does it come down to the person doing the head work, or both?

It really depends on the engine design. Triples tend to start detonating above 150 or so psi cranking pressure on 92 octane. 4 strokes make half the heat of a 2 stroke, so they can run more pressure if designed correctly.

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Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........