1994 Yamaha YZF 750 R - Answered Questions & Fixed issues

Under your tank and likely will need to remove one or both side panels.... I strongly recommend you purchase a Service Manual for your ride. Either Yamaha or Clymer's will help you greatly. Good Luck! Bob If you need further help, I’m available over the phone at https://www.6ya.com/expert/robert_beef7390c57fac0d

Run compression check on all cylinders.

Could your clutch be sticking at lower rpms wanting to stall the bike out try adjusting clutch cable out a bit see if this helps or in as it may not be engaging all the way

http://www.repairmanualclub.com/motomanuals/

set the fuel mixture screw at 2 1/2 turns out. pilot screws 3 1/2 turns out, & the Dynojet 118 main jets had been installed.Stock jets are 122 according to the Haynes manual.
set the float hieght at 12mm, ---------- Mains - 182/172 stagger
Needles - stock
floats - 12 mm to 14mm
pilot jets - 38 (one size above stock, #35)
pilot screw - 2 turns out.----------- ------------ Also click this link for ,more help:-- http://technoanswers.blogspot.com/2011/06/pilot-jet-setting-yamaha-yzf-750.html -------------- This should help.Thanks.Helpmech.

you may need to check that there is no induction leaks

Your bike actually has a generator. The only way to knock in the generator is bad bearings. The knock could also be a bad connecting rod bearing or crankshaft bearing.
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Seems that the crank/timing settings needs a closerr look than to feel that the carb is faulty.The engine is becoming rougher because the firing angle is changed. I also doubt that the carb /jet kit be replaced back with the original as the new jet is not matching.
Now start the engine and set up idle to more than minimum so that the vehicle does not stall but is somewhat smooth. Now try to advance/****** the timing and notice if the engine becomes smoother irrespective of the TDC settings. If so set to the best level and bring down the Idle , do not reduce off air but check the mixture at the exhaust to have this done all over.
Somewhere in the new change a point has been missed..

Since all four light at the same time you have a short. Check the wires near the turn signal switch and then the switch itself. Keep following the wires until you find the short if switch tests okay.

check all vacuum lines you could have a manifold leak...buy some Chemtool B-12 form Autozone if they have any left ..Caution, its highly toxic has MEK in it, use gloves and masks..cleans frame, rims, carb even road tar off you cars paint and its also good for detecting leaks when you spray it around carb hoses..dont use a lot on painted surfaces in the same area.. if that doesn't fix your problem then while your at the Autozone pick up a can of Seafoam and pour 1/3 can to two gallon gas and get on it for about 10 miles and see if that doesnt restore your power..can of Seafoam is $10, i've used it in my car too when it was having trouble starting and it worked fine. I had a similar problem like yours before i new about Seaoam, but it would'nt have helped me though..i bought a salvaged carb bank and cleaned up the bowls tweaked the pilot jet another 1/4 turn since i could get to it easier and man it now rides like a liter bike. i tore the old one apart to see why it was running so bad and when i took off the number one bowl i heard something rattling around in it...the main jet had fallen off! so there are some options . Can i get some feeback? thanks.

I would try borrowing a coil first to see if it is a coil problem, Yamaha CDI units are pretty durable and seldom fail whereas coils are quite a common fault and relatively cheap.

Look at the base of the cyclinder where it bolts to the block. It will tell you what CC it is.

Probably the belly pan mounting bracket is bent

pull a lock nut/nyloc nut on the over side if the bolt is long enough if not use thread lock just dap a bit on the bolt and screw it in and let the stuff set good luck bud

There are 4 rubber spark plug caps on top of the engine's cylinder head behind the radiator.
If you pull them you reveal a hole on each one.Inside that hole you insert the 16mm spark plug wrench tool which must be long enough to reach them.

You have air leaks in the intake that are causing the bike to run lean and idle fast. The 2nd carb problem is probably a pin hole in the CV carb diaphragm.

A “very helpful” rating for this answer? Thanks!

The Key code is only on a tag that comes with key set. if it was not saved or written down in manuel there is no other way to get it.

You may have a bad piston and oil may be getting by.

If memory serves me correct, it doesn't have one. A light comes on when getting low on fuel. Should get about 130-150 miles out of a full tank

Set the fuel mixture screw at 2 1/2 turns out. pilot screws 3 1/2 turns out, & the Dynojet 118 main jets had been installed.Stock jets are 122 according to the Haynes manual.
set the float height at 12mm, ---------- Mains - 182/172 stagger
Needles - stock
floats - 12 mm to 14mm
pilot jets - 38 (one size above stock, #35)
pilot screw - 2 turns out.----------- ------------ Also click this link for ,more help:-- http://technoanswers.blogspot.com/2011/06/pilot-jet-setting-yamaha-yzf-750.html -------------- This should help.Thanks.Helpmech.