Alhazred Posted April 26, 2014 Share Posted April 26, 2014 I bought a '97 750 recently,on my first ride out I noticed it was getting terrible mileage.Today I went to check that the air filter was clean and the choke wasn't sticky,it looked okay.I thought why not pull the plugs to check how it's running and to my surprise they pulled out with almost no resistance and there is also some oil around the base.I'm guessing this is the source of my poor mileage but does anyone think I could have done any other damage?I did about 190 km that day and used 3/4 tank. Link to comment Share on other sites More sharing options...
Member Contributer FJ12Ryder Posted April 26, 2014 Member Contributer Share Posted April 26, 2014 I'm thinking not very likely to have hurt anything unless the threads are chewed up. However, If I were you I'd go ahead and invest in some new plugs. If you stick with the old ones, it might be a good idea to make sure they're the correct plugs and in the right heat range. If the plugs tighten up okay, I'd say you're good to go. Your first name Abdul? And have you written a famous book? Link to comment Share on other sites More sharing options...
Alhazred Posted April 26, 2014 Author Share Posted April 26, 2014 Yeah I'm sure it didn't hurt anything,and good idea on checking the heat range.I think everything will be fine but first I have to get to the front plugs which has been a mystery so far to me.I can`t even get the upper fairings off. Thanks for the reply. Ph'nglui Mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn Edit: I see what I was doing wrong with the upper fairing now. Link to comment Share on other sites More sharing options...
nearfreezing Posted April 27, 2014 Share Posted April 27, 2014 You probably will want to change the plugs, but the fact they were loose suggests the previous owner didn't do the best maintenance. I wouldn't be surprised if changing the plugs doesn't improve the fuel economy. I'd turn my attention to the carburetors next. Link to comment Share on other sites More sharing options...
Alhazred Posted April 27, 2014 Author Share Posted April 27, 2014 The funny thing is,he was taking it to the honda dealership for all the maintenance even having the oil changed. I'm going to change the air filter and the oil/filter today.I guess I'll throw in new plugs also,but they do look almost brand new with a nice tan color(at least the rears do). The dealership was putting GN4 20w50 in it,does that seem a little much to anyone?I think I'll go back down to 10w40. Link to comment Share on other sites More sharing options...
Member Contributer FJ12Ryder Posted April 27, 2014 Member Contributer Share Posted April 27, 2014 Yeah, I'd go to the lower viscosity oil too. I run 15W-40 in mine. Link to comment Share on other sites More sharing options...
spud786 Posted April 27, 2014 Share Posted April 27, 2014 When installing a new plug, always torque break loose and re torque , because the compression washer will continue compressing long after the first torque. This prevents loose plugs down the road. Its only on a fresh new plug you need to do this on. Link to comment Share on other sites More sharing options...
Member Contributer FJ12Ryder Posted April 27, 2014 Member Contributer Share Posted April 27, 2014 If you do that, won't you negate the purpose in using a "compression" washer? I've never done that, and never had a plug get loose. But maybe I've been doing it wrong. Link to comment Share on other sites More sharing options...
TNRabbit Posted April 28, 2014 Share Posted April 28, 2014 The funny thing is,he was taking it to the honda dealership for all the maintenance even having the oil changed. I'm going to change the air filter and the oil/filter today.I guess I'll throw in new plugs also,but they do look almost brand new with a nice tan color(at least the rears do). The dealership was putting GN4 20w50 in it,does that seem a little much to anyone?I think I'll go back down to 10w40. I would think in Ontario a 0W-40 (Amsoil) would work well for you. Flows like 0 weight when cold, thins no more than 40 weight at operating temps. Link to comment Share on other sites More sharing options...
spud786 Posted April 28, 2014 Share Posted April 28, 2014 I seen it happen many times to new plugs, that's why I do the procedure, but no it negates nothing other than preventing a loose plug down the road. Link to comment Share on other sites More sharing options...
Member Contributer FJ12Ryder Posted April 28, 2014 Member Contributer Share Posted April 28, 2014 Well, we'll have to agree to disagree on this one. Some guys actually advocate using a new crush washer when you reinstall the plug. Personally I think that's a bit of overkill. Link to comment Share on other sites More sharing options...
spud786 Posted April 28, 2014 Share Posted April 28, 2014 Hey, if you haven't seen the issue which is quite common, then you wouldn't know any better. most the time new plugs wont lose full torque, just most of it. With todays modern plugs like ngk, I don't even think you could easily remove the compression washer without a lot of effort. Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted April 28, 2014 Member Contributer Share Posted April 28, 2014 Think I will check mine ... Link to comment Share on other sites More sharing options...
Alhazred Posted April 28, 2014 Author Share Posted April 28, 2014 After tightening down the plugs(what a horrible thing to do for the first time)rpms dropped from about 4000 at 80km/h to 3500 at 80km/h. Also gassed up this afternoon,the fuel gauge was just hitting the red and it took 14 litres.Trip meter was somewhere around 200 km.Did another 40 something km and the gauge hasn't moved. They're calling for rain most of the week here and with being really busy at work I won't be able to get out much on it to see what it's like now. Link to comment Share on other sites More sharing options...
spud786 Posted April 28, 2014 Share Posted April 28, 2014 Think I will check mine ... The vfr has tiny iridium plugs and small compression washer, where I've seen the issue is with plugs with larger compression washers, I just do the technique on all, cause it eliminates the issue completely and new plugs stay tight.. Link to comment Share on other sites More sharing options...
Member Contributer FJ12Ryder Posted April 28, 2014 Member Contributer Share Posted April 28, 2014 Just nitpicking, but your rpm won't change at the same speed. The engine is connected solidly by the chain and sprockets to the rear wheel. So at a given rpm your speed will be a certain amount, nothing short of gearing change, or clutch slipping will change that relationship. If you're making more power or using fuel more efficiently then your throttle settings may change for a given speed, but not your rpm. Link to comment Share on other sites More sharing options...
Alhazred Posted April 28, 2014 Author Share Posted April 28, 2014 Yeah...thats embarassing,especially because I know that.Maybe I was just trying to convince myself I fixed the problem.I think it's fine now though,after 95km the gauge hasn't moved much. Link to comment Share on other sites More sharing options...
Member Contributer FJ12Ryder Posted April 28, 2014 Member Contributer Share Posted April 28, 2014 I can dig it. Link to comment Share on other sites More sharing options...
fabio222 Posted April 28, 2014 Share Posted April 28, 2014 Sounds like you might have sorted it. With loose plugs you were probably not burning all of the fuel you should have been and thus getting poor mileage. Might be a good idea to through in some carb cleaner through the airbox or add Sea Foam to your tank to just give the carbs a quick clean...or take them off and do it properly if you have time. We don't have Sea Foam in Ireland but I've heard it mentioned on here before. Link to comment Share on other sites More sharing options...
Beck Posted April 29, 2014 Share Posted April 29, 2014 My usual deal with new plugs is first seat it so the plug and washer seats on the head then turn the ply another quarter to a half turn to compress the washer. You have to be careful not to overtorque the plugs or run the danger of stripping your head..... Check plugs for deposits and clean and re-gap if needed after another 5K miles , then reseat the plug with just a qurter turn max, as the washer had already been crushed from the initial installation. Link to comment Share on other sites More sharing options...
mcrwt644 Posted April 29, 2014 Share Posted April 29, 2014 I seen it happen many times to new plugs, that's why I do the procedure, but no it negates nothing other than preventing a loose plug down the road. that's interesting. Not saying it isn't true, but I never heard of it. Never had it happen either. Huh, maybe I'll do it next go round. Link to comment Share on other sites More sharing options...
VFR4Lee Posted April 29, 2014 Share Posted April 29, 2014 Spark plugs really need to stay in their designated holes. Had one pop out and hang on the end of the wire once with an old VW bus. It did not run so good surprisingly, and sounded like a helicopter as I pulled over. Link to comment Share on other sites More sharing options...
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