gday all, well for those of u who have been following the saga which is my bike, i have some info for you. what happened to my bike was that cos there was no fuel pump and no filter crap got into the carbi therfore holding the needle off the seat and allowing fuel to leak into the chamber. over a long period of time. (the previous owner said he didnt ride it for 6 mths) the fuel would seep into the sump which is why i had 4 litres of oil and fuel when i drained it. when i tried to start the bike the fuel in the chamber caused an hydraulic lock which then burnt out the starter. as i tried to clutch start it (cos i thought at the time it was a flat bettery) the hydraulic lock remained and the back wheel locked up. i replaced the starter and the bike started again. i took it for a small ride to find i had a lot of steam coming out the exhaust. smoke from oil sink to the ground steam rises so this could mean only one thing......yes....... a blown head gasket. this is a result of the fuel in the chamber having to give way as i tried to clutch start it at the weakest point being the gasket. so off came the head. and to the machinist it went. 3 weeks he told me. so a few days later i went back to get it and gave it to a mate at work who has a friend who does that stuff. while the head was away i was thinking about the damaged caused and thaught maybe i have bent a con rod. so i turned the engine over by hand with a steel rule on top of the pistons to see if any was lower than it should. sure enogh conrods 3 and 4 were bent so i took off the chamber and wow they were bent alright. so i rang around for parts and it was going to cost more than 1k to get the parts and fix the head which susequently had 4 damaged exhaust valves. so i rang around the local wrecker and got an engine for a good price and have spent today taking the old one out and putting the new one in. so with a bit of luck which i have none off ill have it ready tomorrow. apparently my engine got hydraulic lock cos of the fuel i was using i used premium but the guy at the bike shop said that alot of bikes cant run premium cos it is alot more dense and therfore fouls the plugs and does something inside the carbi to allow fuel into the chamber. this sounds strange to me. do u guys know anything about this fuel type thing?????? hope u guys r having more luck than me safe riding jeremy
Depends on what one means by dense... The fuel weighs pretty much the same (and thus the true molecular density is the same). However premium has a higher concentration of octane, and thus has a greater density of octane. In general higher octane will result in the fuel burning more efficiently and cleanly (simply because octane burns...), and cause less fouling. The side effect is that since it burns more it can cause increased pressure inside the engine for every spark that occurs - more flamable material the bigger the bang so to speak. So it could cause stress that way. FZR's are supposed to have been designed for use with regular unleaded. However they were also released in the days when premium was a rare find and thus they would have to be. Personally I have found premium fuels to keep my bike running MUCH smoother, and I have a lot fewer issues with my plugs fouling (I used to clean them monthly because of fouling, then switched to premium). I will continue to use premium because my bike runs better.
Uh..... Octane is not an additive...it is an index of anti knock ability. The higher the octane number the slower the fuel burns, as knock is really pre ignition, also called detonation, which is uncontroled burning (explosive) as opposed to a flame front traveling across the combustion chamber. if fact...you probably will experience MORE fouling with premium gas than if you used regular unleaded The fact that you had fuel leak past the needle velves in your float bowls had nothing to do with the type of fuel...and everything to do with the condition of the needle seats Glad to hear that you foun dsa replacement engine for reasonable though and that you got it in the bike bent rods are no fun Jim
Really? I thought I had the opposite experience... When I first got my bike I ran unleaded. It had a tough time, and plugs constantly fouled. Then started running premium and had no issues after that - I always assumed that was the fix... However, now that you make me think... I also cleaned the airfilter, cleaned the fuel filter, replaced spark plugs, etc. So I guess my jump to the premium conclusion was a bit pre-mature... I was always under the impression that the higher the octane the more fuel burns (a higher proportion) overall, and thus runs cleaner... Thanks for clearing that one up!!!
my 89 exup runs cleaner harder and longer on 98 octain. if running regular it only gets approx 150-160k b4 reserve then only another 40-50k howeva on premium 180-200k b4 reserve then up to another 50-70k and thats giving it a good squirt. also it is due for a service filters oil ect so should go even smoother thereafter
See this post for some info on premium fuel, and how it affects your engine. <!-- m --><a class="postlink" href="http://fzr250.com/viewtopic.php?t=2451&highlight=">http://fzr250.com/viewtopic.php?t=2451&highlight=</a><!-- m -->
