Help with YZF 750 motor

tleighbell · Post by **tleighbell** » Thu Nov 18, 2004 1:05 pm

Was just advised by mechanic re: loud ticking from top end. Suspects loose valve guide(s). Engine has 50,000 km (about 31,000 miles), runs fine, no obviously excessive oil consumption, but then I haven't checked. The problem is that this can lead to valve/piston contact and general destruction of the engine and possibly rider (that would be me) at an inopportune moment. Recommendation is to find a new engine because an engine rebuild will be about $3,000.00 Cdn. which is probably close to the value of the bike. Doesn't recommend rebuilding the head only on a high mileage engine because fresh top end will increase load on the bottom end. Top end rebuild will be about $1,500.00 which should be close to the cost of an engine swap. Any ideas out there? How to confirm the diagnosis? Anyone have a YZF 750 engine for sale? I don't really want to go to the FZR 1000 engine. Pisses me off because I just decided to upgrade rather than replace the bike and spent some $$ for suspension and brakes. Anyone looking for parts?? Anyone selling a YZF750? It might be just as cheap to replace the whole bike. Tim

fj1289 · Post by **fj1289** » Thu Nov 18, 2004 7:51 pm

Tim, I've got a YZF750 engine for sale. I was getting it ready to take some pics to list on eBay. Drop me an email. (Click on my name - my email address is in my profile) Chris

2GH FZR1000 · Post by **2GH FZR1000** » Fri Nov 19, 2004 2:45 am

I just rebuilt the entire top end of my bike for $1200 AUS! That was new genuine Yamaha rings, rehone, fully rebuild the head (machine valve seats and stems), carby rebuild and full gasket set. A few of the later Yamahas can use cheaper Wiesco rings (about 1/2 price). I would question a mechanic who says noisy valve guides. Yamaha 5 valves need the valve clearances done every 26,000km so yours are due which can cause the ticking. And also your bottom end will not be strong enough??? My bike has 88,000kms on it and it goes strong.

cterror · Post by **cterror** » Tue Nov 23, 2004 1:01 am

sound´s your mechanic has presented you with an "worst case scenario"=) you cant reliably determine where an clikking noise comes, unless you have opened the engine. it could be valveguides, but it could also be an broken chain tensioner, broken valve or anything. 50th km is not much for an roadbike so the head can be worked with just fine. of course its better to repair things while at it, but if its not necessary i would not do it. and i most definetly would not buy an old replacement engine since they tend to be in less than perfect order. id opt for an good reliable mechanic and go with the top rebuild with new pistonrings and hone.

tleighbell · Post by **tleighbell** » Tue Nov 23, 2004 9:22 am

Thanks for your input bros. I did run this by two other mechanics who I trust and both concurred that this kind of noise is trouble and a good second hand engine is the most cost effective solution. There are two low mileage motors on ebay now so I'll try my luck.

cterror · Post by **cterror** » Wed Nov 24, 2004 4:41 am

damn you´re in canada?.... i would have bought the broken engine from you but its too costy to ship it here

ChuckD · Post by **ChuckD** » Wed Nov 24, 2004 3:22 pm

How bout switching to a FZR/ YAMAMONSTER? I have all necessary parts. CHUCK D.

tleighbell · Post by **tleighbell** » Fri Nov 26, 2004 2:24 pm

Good to hear from you Chuck D. I thought of going to 1000 cc. but my riding skills being what they are and the amount of seat time I get, I figure I have more than enoung power with the 750. I think I'll learn more about riding with less power. Anyone interested in buying a 93 yzf 750? I have a nearly new Ohlins rear shock for it, a set of fully adjustable front forks and AP calipers and master cylinder on the way, probably stuck in customs. New chain and sprokets, braided front brake lines with new pads otherwise stock. Mechanically excellent except for the above motor issues. Cosmetically OK.

tleighbell · Post by **tleighbell** » Fri Nov 26, 2004 6:47 pm

OK Chuck. What would it cost?

Agabinet · Post by **Agabinet** » Sat Dec 04, 2004 2:33 pm

I would get more specifics about what they say is wrong and how they can tell from the sound. Have they had the head off and checked? That's not hard to do (well, relatively speaking!) I went through this with a bad bottom end, and I can tell you that the second motor I bought turned out to have spun big end bearings, so be very careful what you buy. A whole engine to fix a top end might make sense if you really have a lot of shot valve parts, given the cost of shop time and new parts. Better to do it yourself! I'll check my parts bins to see what I have, I reworked one of my 750 heads this summer (port reduction a la mototune usa). Ari

tleighbell · Post by **tleighbell** » Tue Dec 07, 2004 2:21 pm

Ari: Thanks for your note.Two mechanics in the shop with experience with 5 valve motors are convinced from the sound that it is valve guides, not a cam chain etc. Based on my experience rebuilding Triumphs (Meriden, not Hinkley) and Nortons a valve guide is nothing. Actually I am hearing lots of the classic bike guys are having problems with bronze guides in the last year which they think is related to new gas additives. Up here Shell now advertises 5 times the normal cleaning additives in their top octane gas. Don't know if there is any connection with my problem. Anyway, apparently in the YZF you need to get the engine out of the frame to remove the head. $500.00 minimum. Then strip and check 20 valves and guides. About $1,500.00. While its apart you might as well rebuild the top but then the increased compression will accelerate wear on the bottom end. Cost to replace the whole engine is about $1,500.00 but the risk is unknown. I decided not to buy an engine on ebay right now for the reason you mentioned. For this kind of $$ (plus what I meght be able to get for mine) I can be looking at a new(er) bike YZF 750 or maybe a newer 600. However, if you have a head etc or some other potential solution, I would love to hear about it. Despite always covetting something newer, I really like the YZF and don't want to let it go. Tim

Nbot · Post by **Nbot** » Wed Dec 08, 2004 12:05 pm

What's that you say? Got a whole bunch of freetime this winter and plenty of space in the dining room??????? Could be fun......... Also, are you sure the bottom end would be too weak? I dunno....Maybe take up Chuck on the engine, he's selling thins off so cheap its ridiculous! Nbot '94 Fizzer Litre Be alert ... the world needs more lerts ... :)Edited by: <A HREF=http://p072.ezboard.com/bexupbrotherhoo ... ot>Nbot</A> at: 12/8/04 10:06 am

leanhard59 · Post by **leanhard59** » Mon Jan 17, 2005 8:25 pm

Tim, Are you still looking for a motor / parts? I have a used stock head with 4K miles. It was from my backup supersport motor. Ran Great!..No issues. Pretty much a bolt on, although I would replace the valve guide seals...(Which I also have) I also have the whole bottom end...Crank with rods installed from the same motor..Same miles. Let me know. Dan...from Delaware. 302-438-9235

tleighbell · Post by **tleighbell** » Wed Jan 19, 2005 11:09 am

Dan: Good to hear from you. I can't find your email address. I may be interested in the motor depending on what work is required to bolt it back in the bike and the cost to buy and ship. Thanks for the note and I hope to hear from you. You can email me direct at tleigh****@bellnet.ca where **** = bell. Tim

OWO1 · Post by **OWO1** » Mon Jan 24, 2005 11:49 pm

Chuck, For a package deal what do you want $$$ for the 1000 set up?

EXUP Worldwide

Help with YZF 750 motor

Help with YZF 750 motor

Re: Help with YZF 750 motor

RE: Engine

Re: RE: Engine

help with yzf 750 motor

Re: help with yzf 750 motor

Re: help with yzf 750 motor

help with yzf 750 motor

help with yzf 750 motor

YZF750 Motor Help

help with yzf 750 motor

Re: Help with YZF 750 motor

YZF Motor

help with yzf 750 motor

yzf engine