So this problems has stumped alot of people in the past few weeks but if anyoine is gonna know it would be on here
So here goes , bare with me on this
So my dad has had his 4jh since about november , he swapped his triumph trophy 1200 for the FZR as the triumph was too heavy for him , obviously he didnt try to red line in straight away so we didnt find this problem until recently when the weather got nice and he got to know the bike
so the Problem : it refuses to rev past 7000 rpm at all , when you get to 7k it will sit there as if it was on the red line , the weird this is tho , it will rev perfectly clean to the red line when its on the side stand
the other thing is , when you get to 7k it will pull through it but it takes a very very time to do so
wwe have changed the whole ignition system for new yamaha parts and my dad has checked the cards over for bad diaphrams or crap in the carbs but they were all fine an clean , he replaced the main and pilot jets for new ones too
we has also checked for restrictors in the inlet ports , you can see straight onto the valves so thats not it , and from what i know the 4jh is 20 years old now and i believe they are too old to have an electronic restriction on them aswell
one thing to not is we have change the exhaust for a stubby can my dad was given , but that isnt the issue as it does exactly the same thing with a standard can on it , its just alot quieter
Anyone got any advice as to what we could check next ?
