Engine transplant iminent. Achieved, with issues.

[Res7]

I'm about to buy a 2nd hand motor for my gpx 600. The bike is currently at the mechanic, who has told me my top end needs a complete rebuild. He estimates a starting price for this exercize to be around 3,500. so i am buying a motor tomorrow from wmbbikereckers. He says it ran well before dissasembly and doin't blow smoke or rattle, but had a small oil weep from the sump. His price is 599 for engine only. Does this seem like a fair price to you out there is cyberspace? I'm sure at least one of you will have some idea.
Cheers.[xx(]

[Fatgit]

That's not a bad price (have you looked at fitting a 750 as well?) BUT

$3,500 to rebuild a GPx6 top end? You're mechanic in some serious debt is he?

What's actually wrong with it?

[Res7]

Don't have the cash to find out whats wrong with it.
I did the transplant today. used the 600 motor i mentioned.
all went well, I even managed to lift out and in by my lonsome.
got it started all right, but.......
Through sheer exhaustion and not a little bit of stupidity, I put a litre too much oil in it.
i will remedy this tomorrow.
it doesn;t wanna run too well ( a damn sight better than it was though)
would this be attributed to the over zealous oiling?
I really don't know, and am fully aware how stupid tat question is to most of you.
any hints/tips would be much appreciated.
Cheers.

[Fatgit]

what do you mean by doesn't wanna run too well? An extra litre of oil shouldn't affect it that much.

[Res7]

Doesn't want to start, and when it does it sounds like it is first start at 5 in the morning on a cold day.
No torque or any top end, doesnt respond to throtle quickly.
big backfire on attempted start a few times. not just a crackle, a BANG.
I was expecting teething problems with a new donk, I just don't know what to do.
If I can't figure it out soon i'll take it to the mechanic and watch as he starts it for two seconds
and tells me whats wrong.(lol)
Still trying to sus it out myself though.
With the help of you Fatgit. Thanks.
Any other suggestions welcome.
Cheers.
Oh yeah, the gear box clunks a bit when it's struggling to start.

[Booster]

Your carbs or from the new engine,sounds like they need a clean.

[Fatgit]

And a good balance

[Res7]

how is this balancing of carbs achieved?
they are vacume carbs with no adjustments that i can see anywhere.
and they are not new ones anyway.
they jets have been drilled out from .9 to 1.5 to accomodate the pod filters.
as explained in the mad postie's build up.
I bought it off him and rode it from bris to sydney in early feb.
gave the carbs agood clean after i arrived down here. and they were fine for a while.
then the motor started the slow decent into fuckedness a few weeks later.
I don't THINK it's carbs but that doesn't mean much.
I am very interested in this balancing schtick.
Please tell me more.
the quicker I am made a fool of the quicker i can get it fixed.
I have now spent all of my somewhat limited resources,
and as such wil be entirely without transport until i car fix it BY MY SELF.
Nooooooooooooooooooooooooooooooooooooooooooooooooo ............

[Seifer]

Haha you fool, have a search and you will find a guide on how to make urself a set of guages and adjust them. You should buy a proper mercury balance tool but that'll set you back around $150. Between each carb will be a small phillips head screw which you need to adjust to achieve a perfect balance.
It sounds like it is the carbs and until you have them tuned you can't afford to rule them out.

Here I'll do you a favour, here is a cheapy guide on how to make your own synchroniser. Not the best but better than nothing.
http://www.powerchutes.com/manometer.asp

[Res7]

thanks Seifer, I'll give it a try.
Cheers.

[Res7]

I had a look at it but i dont understand what he means by "hooking each side of the manometer to each of the carbs".
Where do I hook a tube to my carbies?
Cheers

[Seifer]

Ok if they are vacuum like you said there should be a thin tube running to the tap on the tank. There will also be 3 rubber caps in the same place on the other carbs. This is where you attach those rubber tubes to. With that guide i sent you, you will have to test them by putting them on carbs 1&2, then 3&4 and finally balancing 2&3.
Make sure the other carbs you arent balancing has a tube going to the tap and the other one has a cap on it.
This is the best pic i could find of GPX 600 carbs, I've circled where you should attach the balancer.
http://www.streetfighters.com.au/forum/upload/69282627624224.jpg

[Res7]

Thanks for the step by step, I am assuming the bike has to be running first to check the vacume.
One other dumb question, are the screws i will be adjusting mixture screws?
As i've said before the jets have been drilled out,
and i'd like to be able to adjust the mixture.
Give me a gemini carb and i'm all over it.
this multi carb stuff is intense.
so much i don't know.

[Seifer]

Nope, mixture screws will be on the other side of your carb. WHat the screws you will be adjusting do is effectively adjust the amount of fuel being sent through. Obviously if one cylinder is getting shite loads more than the other u will be running like shit.
TO balance your carbs you do need your engine running and should be warmed up too.
THe picture below shows where your mixture screws are. These mainly affect your idle. FInd the specs for your bike for where there settings are, most probably between 2-3 turns out.
http://www.streetfighters.com.au/forum/upload/90177368523746.jpg


Have a quick google for carb tuning, not the hardest thing to learn but a good trick once you know how. You should really rebalance your carbs every time they come off the engine.

Check you have a good flow of fuel to your carbs, check float heights, check your plugs are good and you're getting a good spark. check everything. Remember you need three things for your engine to run, fuel air and spark. Make sure all three are working.

[Seifer]

The little black dial on the bottom right of the carb in the photo above is your idle adjuster. Turn it to change the revs your bike idles at.

[Res7]

Got good spark and new plugs at the right gap.
Already knew what the idle adjuster was. (I have to know something)
Built guage thingy and works well.
Managed to get it running long enough to balance 3&4,
but am having issues getting it to run for 1&2.
When i'm trying to start it over and over the gearbox is making clunking noises occasionally.
Is that likely to be normal, as bikes are made to run not try to?
Or is it likely to be bad?
Now i shall try adjusting the fuel air and see if that changes things.
Thanks again for all your help,
I'm just trying to learn.
Cheers.

[Res7]

ok, carbies balanced. now the battery is flat, so it is charging. lol.
I'll see if it wants to play and if it will run when charged.
not too keen to fiddle with the mixture as i'll have to take the carbs off to do so.
The gap between the screws and the motor is too small to get even a stubby driver in.
1&2 were pretty close to spot on to start with, but left & right were well out.
I really hope this sorts some of the issue out at least.
We shall see.
Keep you posted.

[Seifer]

Go to bunnings and grab one of the screwdriver bits for a drill. Small flathead. Too easy.

[Fatgit]

If memory serves me correctly the primary drive on those motors is chain, and can snatch occasionally, especially after they've done a few miles. If it still occurs when you get the motor running correctly then you can worry about it.

[Chris41]

If the carbs are out of balance chain primary drive engines make some bad sounds, from the chain thumping to the clutch rattling. Usually it goes away when revved.
Are you sure the old engine was fucked if you're still having this much trouble.

[Res7]

It was a different kind of trouble.
The engine sounds much better when it does run now that the new one is in.
now that the carbs are pseudo balanced the clunking has gone away.
Thanks for the tip guys.
I'll try to find out how many turns out the mixture screws were standard
tonight on the net.
the main jets were drilled out by mad postie from .9 to 1.5 apparently.
Neither do i know what the 1.5 is( mm? ), nor do i know what adjustments to make to the
mixture seing as it has bigger jets, and pods instead or an airbox.
(god that was a confusing scentance to write.)
Guess saturday is trial and error day for me.
Cheers again for the advice guys.

[Res7]

Update. Found an airbox, but it is in brisbane.
Also found a mechanic who tinkers from home not too far from where i live.
He is going to have a crack at the bike for me and show me whats wrong and how to fix it.
Nice bloke.
I'll let ya'll know what the issue ends up being.
Cheers.

them is the best mechanics to find...he doesn't work for wages for some fucktard dealership,he works for himself for a living and is passionate about his work and is excited to be able to help you and show you what was wrong and what your paying for to be fixed and how you can fix it yourself next time.And he's probly got more idea about all makes and models than 10 dealership mechanics combined.
Fuck they're a rare breed these days tho.

getin back to the manometer ... use 3mm tube with 6mm end joiners and 5W fork oil,you can adjust the flow rate with the cable tie pressure.

[Res7]

Thanks Davo, I got the manometer sorted and used it with some degree of success. My home delivery mechanic is a really nice bloke and as you mentioned, wouldn't be doing it if he wasn't passionate. He told me that many shops won't touch a bike over 5 yrs old nowadays. And your manometer has a new convert.
Cheers mate.