[boris.h]79 GS 550 / 673cc project

[Ace07]

Hey Boris I am really enjoying the thread. I found it awesome that you were 3-d printing parts. I plan to 3-d print a new dash for my bike. I found all the information interesting, but a lot of it I didn't understand because I have never done any thing like this before.

[boris.h]

thanks ace

I just started to play with the markforged two, today (nylon / kevlar, nylon / fiberglass, nylon / carbon fiber)... Getting a LOT of ideas now!

[boris.h]

an idea, using nylon / carbon fiber.... It will be on the bike!

[boris.h]

Hello again!
Not o lot of people interested in my project....

BUT
I was happy to get back my gs 650 head yesterday, aluminium welded. I just have to make again the second combustion chamber and put new valve seats..... still, still, still a lot of work and I want it finished for the next summer!
Could someone give me some advices about degreeing the 550 camshafts? What is the best setting?

thanks a lot!

[boris.h]

hello all!

I got the head back and almost ready to be used, this week. I measured the combustion chamber volumes, with the gasket surface milled some 0.1 / 0.2mm.... just for start.

Unfortunately, I measured, with a 1.25mm thickness head gasket a ratio of... 8.95:1!!! Which is not so big. I'm a bit disappointed, I think this is because the valves are a bit "back" in the head. So I have few questions:

- which maximum value is possible, with your experience, for milling the head to increase the CR?
- Moreover, I think that, even if I mill the gasket surface, The squish band will be the same which is.... the value of the gasket thickness? I think 1.25mm is a "too big value" and could be reduced...

- I would like to get a ratio of 10:1, so I measured that I would have to remove maybe 1mm height of the head.... I think this is a lot, but maybe not, your experience would help me to choose.

I'll make a first assembling to measure the distance between the valves and the pistons this week-end and the squish band clearance. I think this would help me to choose...

any feedback possible here????

[boris.h]

Ok,
Still waiting to see if I can increase the CR without having any chance to damage the valves and the pistons..

I think I will be able to start it before end of may....

[boris.h]

[boris.h]

ok, even if i still have to finish some parts, like the new velocity stacks and some finitions...i am ready to do first start tomorrow....

[Rensdw]

ok, even if i still have to finish some parts, like the new velocity stacks and some finitions...i am ready to do first start tomorrow....

I just looked through your whole thread, pretty amazing stuff dude!

How did you fix your CR issues? did you measure the valve>piston clearance and then milled the 1mm off?

Im doing something similair to a GS450, see my thread

Good luck!

[boris.h]

Thanks dude.
About CR stuffs, I milled first 0.4mm because of a full combustion chamber rebuild (welding...), then I did 1 first try just to measure the distances and then I removed 0.6mm. The limit for me was the intake valve / piston clearance (1.25mm).

[boris.h]

Ok! So I did few start but nothing, no fuel at all on the spark plugs... I decided to go until 2.75 turns on the fuel screw... it started immediately, without any crappy noise... yes I won So happy everytime a rebuild engine start...
So, My question concerns how many turns have I to put to my bs 32 carbs??
The configuration is quite "not oem"
- gs 650 ported head on gs 550 base "the famous swap", plus the ported and milled head
- no restriction for the exhaust: bandit header, and danmoto conical end
- velocity stacks



For the instant, I put 3.25 turns, and the idle is about 1500 / 1800 rpm, so a little high. Regarding the fact it did not want to start at 2.75 turns, and it wanted to start immediately at 3.25 turns...I did not any plug shop but I think i am too lean... and i wanted to ask you how many turns I had to put?

thanks a lot

[Rensdw]

For a guy with your knowledge I would have thought you know how to adjust the air screw!
You need to adjust the airscrew to find the highest RPM, then adjust the idle to where you want it and repeat.
Look for some Youtube video's I'm sure there are some around.

In the end, put it on a dyno with an A/F sensor and do it properly

[boris.h]

Yes that is that I want to do after. For "my knowledge", yes I know how to do, but I do not want to spend time looking for something someone else knows... thanks a lot

[boris.h]

ok, started to disassemble my carbs to try some changes...
--> raising the needles few notches
--> increasing main jets sizes maybe --> I currently have mikuni # 112.5 ones.... what do you think about?

Also, I have My clutch not working now. Discs ok, but disassembled 6 months. Maybe they are stuck, or forgot something. I rized the back wheel to try, with the clutch lever pulled, doing something but it seems like no clutch is working...

[boris.h]

ok, speaking to myself lol but the aim is to keep something to help and share my issues...

- clutch issue: that was the basket big central nut: when I unscrewed it, the basket got free... Maybe I overthightened it.. The manual says between 40Nm and 60Nm, I'll try to screw it again, to 40Nm and see how it works....
- carbs jetting: I'll test # dynojet 160 main jets, drilling old jets... as the dynojet kit says. I think I am too lean.