Hey everybody. I have a tough question for you. I bought an 87 CBR1000 backet case a while ago. Iv'e been building it into a very custom street fighter. Problem is it has over 30,000 mile and it sounds like it has some piston slap. I don't really want to go through the expense of rebuilding it, so is there any other motor that could fit in this frame. The only one Iv'e seen had a Ducati 900ss, but I'd like to stay with a 4 cylinder. If you help me out I'd be happy to post picks of the finished bike.

 

Mr. sicle... atop end is feasible as a quike and dirty way back in... you might have more into all the enginiering, engine pipes cooling system adaptation... unless your look'n for stange. CBR 'fighters, are stange to start w/.
In gixxer world(yes I live there too) a late 70's/ 80's air cooler will fit in a gixxer chassis, up to 92...CB1000, might be close. I'd do the topend, esp if you can do the labor and think you have a decent bottom end or a crashed basket, w/ a good engine. Is the eng noise diagnosed correctly, considering the longevity these eng. are known for... run it for a while??? Clean and free Ripp'n

 

Hey:

The newer cbr1000f 90-99ww, 91-96 usa, fit . You need the newer rad/themo and have to make a few brackets,

also the 94-95 cb1000f bigone works but only has a 5 speed tranny


Dub

 

the cbr1000f early motor is IMO the best of the lot, why would you want to change? i say rebuild and lap up the 100+hp

 

I was kinda leaning toward the rebuild anyway. I was thinking swap because 1000f motors are kinda rare on Ebay, and rebuilding is a little intimidating. Thanks for the advise.

 

If I was going to do a rebuild, I'd install a big bore kit - takes the engine up 50 cc - they say it's good for an extra 25 hp, don't know if it's true - you can find them on ebay for $440.

 

I've got a 130 hp 1000f motor for sale if you're interested.....

 

What kind of longevity has been achieved with these engines?

Joel, what years are you talking about. When and how did the motor change. Any good reading on the subject?

 

Rebuilding to cure your piston slap is not a difficult job - you ca do it with the engine still in the frame. And its got to be easier than trying to fit a completely different engine in! Even if you decide to take the engine out, stripping it down to replace the big end and main bearings isn't too difficult. Let me know if you want to try and I'll give you a guided tour!

On longevity, my first engine did around 70k miles before it started to use oil. Luckily I found a replacement engine from a crashed bike that had done around 20k miles on Ebay that was really cheap. I just swapped them and that was 25k miles ago! The replacement engine is great.

The big bore route sounds attractive and is something I have considered. Getting big bore pistons shouldn't be any more expensive than Honda ones. Just make sure that you open the combustion chambers out a little to avoid getting too high a compression ratio. It's easy to calculate how much extra volume you need in there.

Good luck with whatever you decide to do.