GT550 Blue Smoke Devil

[thebronze]

You can adjust the amount of oil that the pump injects... just have to adjust the cable... should be in the manual... I've done it in the past, but it's better to try the jetting 1st... make sure to have plenty of spare plugs on hand as You will foul a few.

[ctluba]

Miracles do happen!!!!!!!!!!!!!!

Pistons showed up today. Dropped them off with the jugs to be bored, will be ready tomorrow afternoon.:shocker:

[ctluba]

Ok, after about 6 hours in the garage wrenchin and drinkin beers I got the devil back together. Went with the .50 over piston kit. Had the cylinders bored and ports chamfered. I went from size 95 main jets to size 110. I also raised the needles by one notch, the clips are now set as low as they can go, meaning the needles are as high as they can go. I figure may as well run it rich, check the plugs and then I can back to 105 main jets if it way too rich. I just couldnt stomach it if I grenaded this fucker again!!!!!!!!!!!!! Run it rich, Bitch!!!!!!!!!!!!!!

Read the manual as I went



Slapped on the pistons with a nice coating of 2 stroke oil



Bolted the freshly bored jugs on



Put in the new jets and raised the needles



Threw the head on and bolted up the chambers



Took a couple of glamour shots with the body work on, notice how I trimmed the bottom of the tail / seat pan off.









Gonna fire her tomorrow, the nieghbors are already pissed after yesterdays little "incident"

[thebronze]

I'll say it again..... damm do I love those pipes.... Good luck with the run in...

[ctluba]

Thanx dude!!

Ya, that was a hard lesson on two stroke tech!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I think I did enough with raising the needles and increaing the main jet size by a large margin. should, I'll say again, SHOULD, be runnin rich at these settings. I will run her in at a nice easy pace and check the plugs. With the colder weather the jetting may be close. If too rich I can always back down the jet size. I am all paranoid now after blowin that piston. I am thinkin I should be good though.

[ctluba]

Some daylight photos.

Notice some small changes that I think look way better. Trimmed about an inch and a half off the bottom lip of the tail / seat pan. Was way too chunky lookin before. Also repainted it and of course put on some stickers!!!!! Rearsets and rear brake master and fluid res are also permanently mounted up now.

[ctluba]

I am sorta confused. I understand that the prevailing idea on triples is to run a slightly larger main jet in the center cylinder carb. The idea being that the center cylinder is going to run hotter because it is pancaked in between the other two cylinders, therefore get more fule in there to cool and lube the piston.

I looked in my shop manual and it said the stock jetting is size 95 jets on the two outside cylinders and size 92 jet on the inside!!!!! When I took my carbs apart I  was pretty sure there were 97.5 size jets on the outside cylinders and a 95 jet in the center. Ok, that follows the idea in the manual, a smaller one in the center. But why a smaller one in the center? Isnt that the hot cylinder, ie needs more fuel to keep heat down???

So anyway, I went up to 110s across the rack of three carbs and raised the needles all the way up, which is only one clip above where they were. I fired it up this morning and the two out side cylinders were popping strong against the palm of my hand. The center cylinder felt weaker and not firing as often. I ran it for a few minutes to seat the new rings in. After a little while I noticed the middle cylinder pipe was not firing at all and the outside two were popin strong.

I pulled the plugs and I think it didnt run long enough to really see any coloring difference. They were a little brown and wet. I suspect that maybe the center cylinder was gettin too much gas and gas fouled the plug. That is why it was not strong at first and then went out.

Anyway, I was considering dropping the center carb main jet down to a 105. Now that I think about it, just running it in the driveway, the main jet would not even be in play correct??It would be running on the low speed jets and maybe the needle at midrange.

I am going to have my brother come over and tweek with this thing. Maybe the timing is off. Maybe there is a weak coil to the center cylinder?? We will see. Just baffled as to what caused the burn through. Also, the center cylinder did seem to be runnin a little weak prior to the burn through.

*****Any two stroke tunin gurus out there with some input for my dumb ass???****************

Gonna check the ignition timeing, coils, wires, jets, every freakin thing!!!!!!!!!!

One thing for sure, when this monster is dialed in correctly it is gonna RRIIPPPPPPPPPPPP!!!:shocker:

[JRK5892]

glad to see her back on the road! video of her running is a must!

[ctluba]

Hopin to get all the jetting straightened out this week.

Video will be first order of business when she is fine tuned!!!!!!!!!!!!!!!!!!!!!!!

[bikeboy]

*****Any two stroke tunin gurus out there with some input for my dumb ass???****************

I got nuthin' on the tuning I'm afraid, but damn, she's looking hot

ian

[cobraace2]

OK I will try and help I'd start the jetting by going one up on the pilots and 2 to 3 up on the mains. Make sure that you jet all 3 carbs the same though. Stock jetting has the center carb 1 size leaner than the outer carbs. A common mistake in jetting the carbs is to have the center 1 size richer than the outers. That comes from a misprint in one of the popular aftermarket manuals.Also elevation is a big factor, what air filters are you going to run.and remember chambers have a super charging effect you my need to back of the timing to prevent pinging   hope this helps

[ctluba]

Thanx for the input. I did go with 110 mains on all three carbs. I am running the stock air box and filters. I am going to check the points, timing and coils this week. I think I am very close. A little tweeking should get me there.

Thanx again.

[teazer]

Center pot uses a smaller main jet with the OEM exhaust because the center pipe splits into two small pipes for a 4 pipe exhaust. That arrangement for some reason needs a smaller main jet.

Triumph and BSA triples tended to run hot on the center pot and that led to the belief that the same scenario occurs on all triples.  It doesn't.

At idle and small blips of the throttle, you could run it without main jets and it would be fine. The mains do work over much of teh range but hey are not the main event at small throttle openings.

Pilot jets should be new stock or maybe one size up and the needles will probably end up on the center clip or maybe one clip lower.  All the way raised is too rich for Jemcos plus stock air box and filter.

The key to two stroke street bikes is to keep the mid throttle rich enough.  They tend to melt at part throttle cruising.

[Swapmeet Louie]

Center pot uses a smaller main jet with the OEM exhaust because the center pipe splits into two small pipes for a 4 pipe exhaust. That arrangement for some reason needs a smaller main jet.

Triumph and BSA triples tended to run hot on the center pot and that led to the belief that the same scenario occurs on all triples.  It doesn't.

At idle and small blips of the throttle, you could run it without main jets and it would be fine. The mains do work over much of teh range but hey are not the main event at small throttle openings.

Pilot jets should be new stock or maybe one size up and the needles will probably end up on the center clip or maybe one clip lower.  All the way raised is too rich for Jemcos plus stock air box and filter.

The key to two stroke street bikes is to keep the mid throttle rich enough.  They tend to melt at part throttle cruising.

This is sound advise... Use this as a guild line. Just remember, EVERY bike is different. So what you find on the net that worked perfect for one person, will more than likely still need a little tweek'n for your application.

[teazer]

Forgot to mention that a good electronic ignition would be a good idea. Newtronics, Boyer, Ignitech, Accent, etc.  Take your choice.

And back 2 degrees out of the timing to start with and add back if it's safe to do so.