84 gs750

[Guest]

I have a 84 gs750 with a rebuilt top end.Complete rebuilt head with new everything. The motor was broken in.I changed the ignition plate and changed the cdi and put a different wiring harness on .I have 34 flatslides on it with a 4 into 1 header. It runs pretty good and it idles nice.My plugs look real good.My bike on a cooler day as in 17 celsious (62 american lol) it was at 118 cel ( 244 american) .I am not sure where to look for the heating problem.Could the oil cooler be plugged or just old?.Any help would be great.....I know the new motor might be tight but i don`t think it would run this hot.

Thanks in advance....

Bill

[Billy Ricks]

Do you have any idea if the head was milled any? If it was compression is most likely a little higher which would explain some of the extra heat. Timing could be advanced a little too since you changed things there.

[rotty]

They said they milled a little off to make the head true.I am not sure how much.I know that doesn`t help me or you.How can the timing change on my bike?.i didn`t think you can advance the timing on the 84 750's?.If it is higher comp would a bigger cooler work?

[Billy Ricks]

They said they milled a little off to make the head true.I am not sure how much.I know that doesn`t help me or you.How can the timing change on my bike?.i didn`t think you can advance the timing on the 84 750's?.If it is higher comp would a bigger cooler work?

You said you changed the ignition plate. It or the pickups may be positioned different. A bigger cooler should help if it's compression related. Have you played with the jetting any since the rebuild?

[rotty]

I bolted the plate to the same place?...I have been playing alot with jetting.....It seems to be right on with the colour of the plugs..Would a few mill taken off make a difference?.So maybe a aftermarket cooler then?.

[Billy Ricks]

Are the temps staying up when you're out riding with air flowing through the cooler or is this at idle?

[rotty]

they seem to get higher with air going through the cooler... and at normal riding

[Billy Ricks]

I'd give it some time to break in and see if things get better. On top of the head being milled the base and head gasket may be thinner than stock. Can you run a compression check to see what numbers you get?

[rotty]

I might be able to do a comp check..There is no way i can ride my bike in the summer or spring when it gets hot.Do you have any idea what kind of cooler to put on my bike?.

[SVSooke]

Going by the temp gauge?Not to sure how acurate they are.Mine barely gets on the scale,ever.

[rotty]

I have a vapor gauge on my bike.I checked it against the oil temp with a proper meter and it was one degree out.I am going to check the difference between the inlet and outlet hose on the cooler and see if there is a difference.If that seems fine then maybe it might be the pump or something?.I am just guessing.

[Billy Ricks]

There is a thermostat that opens and closes to let the oil reach a certain temperature before it goes to the cooler. That could be where the problem is. There's an oil pressure regulator in the pan that might be on the fritz too.

[rotty]

Where do i find the thermostat that opens and closes?.One more thing if it matters..I have a 4 inch mid pipe then a m4 moto gp muffler on it.I was wondering if there is to much back preassure with it being to short?.

[Billy Ricks]

It's actually more of a pressure valve. There's a plunger built into the oil pan near the left front of it. Part 4 is where it would be extracted from by the looks of the diagram.

[rotty]

Thanks for the pic and help..I don`t think i can get new ones from part shark or bike bandit.It looks like all internal parts are discontinued.Is there a way i can check to see if the parts are still working?.