|
Engine Knock
I have a 1996 Yamaha Virago 1100 with only approx. 6000.00 miles on it. When I start this bike I get a knocking sound from the engine. The knocking sound is at its worst when I first start the bike, and when I first drive it before it is fully warm. The valve rocker arm clearance is within manufacturers specifications. A mechanics stetshescope indicates to me that the knocking sound is originating from the rear cylinder. I am hesitant to believe that the knock is a wrist pin or crank knock with only 6000 miles on the engine. The bike has been stored for 10 years. I just had the new kits installed in the carbs. The bike starts fine, but does not run as smooth, or steady as my 1995 Virago 750. Question: Is is possible that improperly synchronized carbs can cause this knocking sound? I hesitate to strip apart an engine with only 6000 miles on it. Has anyone else experienced an unacceptably loud knocking sound from their 1100 virago engine, which is at its loudest when first starting/driving the bike? Your advice is appreciated.
|
|
Re: Engine Knock
low miles,,,, the engine is not broken in good. any other work been done on this bike by anyone else? always start with the rediculously obvious,,check your oil to make sure there is no fuel in the crankcase..check your sparkplugs see what kind of condition they are in,,also ground them to the cylinder head and see what kind of spark you get.. next i would check the cam chain,,make sure its tight and still together,,you might unhook your oil line to the head to see if oil is coming out...is the noise directly related to the starter? when was the last time the oil and filter were changed?,,was the filter put in right,,,keep us posted yg
|
|
Re: Engine Knock
YG. Thanks for the prompt reply. From the review of the e-mails posted on this site it appears as if you help a lot of us Virago fans. You are good people.
Oil, filter and plugs were changed approx. 400 miles ago. Oil filter is installed correctly. Made no difference to the knocking sound. I pulled the plugs tonight. Both plugs have turned black, but no carbon deposit at all. Most of the 400 miles on them were highway (60-70 mph). There is a slight miss in the engine and still the occasional spit. I have tried both regular and premium gas. I have only put 600 miles on this bike since buying it, but am confident that it never saw a wrench before I removed the valve covers to check the rocker clearances. All of the original finish on the engine and engine bolts is factory pristine. No wrench marks. I think that maybe I'll take a visit to the dealer to get the mechanic to take the bike for a run. This is really my type of bike and I don't want to take any chances on doing severe damage to the engine. I'll keep you posted.
|
|
Re: Engine Knock
anyway i can help,i'll try..but i have to thank all the guys and gals on the other virago support sites,,
viragotechforum.com ....and..... viragoownersclub.com,,, as many wise folks that visit these sites we'll get all the vgos back on the road..great ride..yg
|
|
Re: Engine Knock
|
|
Re: Engine Knock
yes, check your left side cover where the window for time is at. remove that cover as you will have to replace the gasket upon doing so. if there are copper color deposits in the oil or anywhere on that side of the engine it is your crank shaft; brass or metallic shiney metal, its your rocker arm. sorry, I felt like shit when I found out too.
|
|
Re: Engine Knock
Only thing else I can think of is
-timing late firing? (think of the run-on sound of a car) which might be more affected by and fuel air mixture on the one carb if it has aftermarket exhaust.
- more of a piston slap? If the previous owners tended to rev the crap out of it when first starting, or you have an problem manufactured piston. This would change a bit when the engine is warming as the piston expands. Do a compression test for the hell of it to see if there is any difference between the front and rear cylinder. At 6000, I wouldn't expect much.
|
