93 "crack, snap and pop"

Hello,
At cold start up just as the motor fire up it will idle for a short while (sounds good) and then a very loud "Crack/Snap" sound. since the motor sounds good before the "crack snap and pop" I don't think it is any ring issues, valves, bearings or transmission. If the motor is already warmed up it does not make the sound as much. I have been shutting it down immediately for fear of something very bad and a possible "lock up" at speed. So if anyone hear has heard of this, let me know.
Could it be the starter clutch gone bad?
Bike is a 93 VFR with 1950 miles, but has been in storage for twelve(12) years. Just did a total carb/jet cleaning, de rust/POR15 the tank, fuel lines, filters, all new fluids, battery and new tires (old tires became ABS plastic).
Thanks all

 

There is no hope for the bike. Lucky for you I am willing to take her off your hands so that you don't have to deal with the problem. :biggrin:

Where exactly do you hear the sounds coming from? Is it an engine related sound or an exhaust backfire? Sorry to say but your description is a little vague and we need a few more details. The first step is to narrow down where the sounds is coming from.

Hopefully you can get this sorted since that bike is practically a museum piece with those low miles.

Regards,
Rollin

 

could be cracked starter clutch, yes.......

 

Maybe I should just unload this bike..... but I can't, it's that awesome:biggrin:
This sound is definitely an engine mechanical related sound, not just a back fire or timing thing. It sounds like a spinning gear suddenly making contact with a non spinning gear and the "teeth" not matching up.
If the starter clutch is cracked, what should I be looking for once I drain the oil and take the right side clutch cover off?....

 

Starer clutch

Here is a link with a pic, a very simple repair and a gen2 starter clutch will fit.
http://vfrworld.com/forums/first-se...424-chatter-noise-cold-vf750f.html#post209068

 

"Crack, snap and pop" and I mean POP

Some bad news, after draining the oil (which had a slight gasoline smell?),removing the right side cover and the starter clutch (which did have a small crack) I looked deeper into the cases with a flash light and AUGH! I saw a hanging connecting rod. I now know what that awful sound was. At preparing a motor that has been in storage for 12 years, I must not have lubed up the cylinder walls enough. Took off the four spark plugs and it appears to only be the right side vertical "rear" cylinder that is at fault. With the connecting rod flapping around in there I am concerned that more damage may have happened (piston, valves, engine case, etc.). What years are interchangeable?
'90,'91,'93. Does anyone have a motor lying around? Seriously, not sure what my next steps are, any advise would be helpful at this time?
Thanks

 

Watch e-bay brother, engines do show up.

BZ

 

ENGINE MOTOR RUNS GREAT VFR750 VFR 750 VFR750F HONDA:eBay Motors (item 170410721821 end time Dec-22-09 18:54:05 PST)

91 1991 VFR750 VFR 750 INTERCEPTOR Running Engine Motor:eBay Motors (item 360173066646 end time Dec-18-09 10:07:31 PST)


would make an offer for $300 for either one of them, they have been listed like 100x...

 

find a motorcycle salvage yard in your area and you might be able to buy a totaled bike with motor cheap.

 

The ticking of a VF500 engine is normal. This is most likely from the cam chains and/or tensioners but is not the same issue as the larger VF's. Your sound poses no problem and if it's like the other VF500's it will not get worse.

Actually, I'd say you've found the reason it was in storage for 12 years. My guess would be that the rod went from abuse and/or improper break-in and that's why it was parked.

 

Thanks to all the ideas about finding a new motor, ebay, salvage all are on my list of options.
When I put the VFR into storage 12 years ago it was running great, and I tend to do engine break-ins by the book but unfortunately it was not prepared for storage thinking I was going to visit it and do start-ups every now and then. Well, I didn't. This past month I have been cleaning out carbs, lubing cables, de-rusted the tank,fuel lines are new with a new fuel filter, air filter and spark plugs. Knowing it had been sitting for a very long time I put some oil down the spark plug holes and hand cranked the engine to help loosen the pistons if they needed to be. Next was to do a carb sync but she started and seemed to run fine (considering). A week later I went to start her up for a test run and "Bang, Snap, Pop" then nothing, thought I had a dead battery so I pressed the starter again and again and it started but with an occasional crack, snap, pop and thats when I thought it might just be the starter clutch.

 

Quick question. Is a 1996 motor a direct install on a 1993 VFR750F?
Could I install my heads, side covers water pump, carburetors, etc. on this engine?
thanks again everyone

 

IT's a real strange thing whatever went wrong.

Could you describe where the rod broke, top, middle or botton at the crank??

Photo would be helpful if you can.

 

That sucks!!! Happened to me also with my 5th gen... With mine one of the nuts that hold the connecting rod to the crank completely vibrated off and then snaped the other side off throwing the rod through my lower case. I was in much the same situation as you except my bike was a wrecked project bike I bought for $500 to fix up and the main reason I bought it was that the motor only had 6K on the odomiter. I was super pissed and almost scraped the project. Luckly I found a good used motor on ebay and went through with the build and I am glad I did. Going that deep into your bike gives you a chance to fix everything:thumbsup:

 

Wow! My noise is not near as scary as yours! I have a strange noise at start up, too. Mine happens every time I start, regardless of temp or prior use. The bike starts, idles for about 20 - 30 seconds, then I hear two clicks. The motor always sounds the same and I have no concerns of internal damage. It sounds to me like a relay turning off. Any ideas what this might be.

 

Squirrelman, the con-rod is broken off about an inch up from the crank shaft. (I tried to photograph this put the flash would get block by the case. I'll try again next time) It looks pretty chewed up, cannot see the other half but I assume it's still with the piston and pin. The bearing seems to still be in place because the remaining rod still rotates smoothly about the crank.
Their was small bits of aluminum I removed when I took the right side cover off, so I am thinking that the skirt of the piston is all messed up and probably some of the case. Now I'm hoping that the connecting rod didn't crack the case somewhere, or push the piston up into the valves and do more damage.
I am planning on finding a used motor, and when I do I will open everything up and see the extent of damage. If the heads are OK I may put my heads on the used cylinder and cases. What years of this design is an easy engine swap? I think it's '90-'97.
Steven113, yes I may do the same thing, except I may throw the used motor in so I have my ride back, then take my time with my original motor and build it up the way it should be, not to mention learning something new, any pointers or advice would be helpful. thanks again

 

I am not sure with your year model what will fit other than not anything newer than 97 will not for sure. I am sure some of the 3rd and 4th gen guys would know the answer to your question.

 

A fourth gen engine will fit.

 

STRANGE the rod broke at a very strong location, near the crank.

Something catastrophic must have happened to cause it, like a dropped valve......?