nc24 very low compression, fkd ?

[sandfish]

Arrrrrrrrrr just run a compression test my 24 restoration project #1-120 #2-60 #3-110 #4-90 not vgood the compression increased a bit with a bit of oil in the bore, when look at the inlet valves i can see carbon deposits, so I'm thinking rings and may be valves, that could be the problem as no one lists them as far as I can see, any one got any ideas ? the bike was running befor the strip down, all be it not very well and the last person to tuch it left me one of the airbox screws in the inlet, so this valve looks a bit tatty but this cylinder has the best compression!

[spooky]

Have you set the valve clearances lately. Maybe the valves are not sealing up, or they may need ground in, or just cleaned up as you say theres a bit of carbon build up.
Anyone know if nc30 rings fit.

[sandfish]

not got that far yet mate, I would like to have the parts b4 i start if poss, or know that I can get them, head gasket should be ok as i have been told nc30 fit?

martin

[spooky]

You could always get a 2nd hand engine as theres lots on ebay cheap

[CMSMJ1]

I'd have a look at the valves first - easy and cheap to do.

I do recall that I sent someone a used NC30 gasket to check against the '24 and that it was bob on - same NC13 motor at the end isn't it?

[Neosophist]

Does your compression tester thread in? If so make sure it's in and sealing properly, I had an engine before that had odd compressions, the tester was leaking :D

Check the valve clearances and signs of a sticking valve or your head gasket may have gone.

These engines are pretty bulletproof though, so if its dead it's had some serious abuse / neglect >.<

I wouldn't spend much money messing with it though, espeically if it's serious, it's going to cost and arm and a leg and there not worth the money, especially if the bores are gone.

You can use NC30 head-gaskets.. list price for inlet valves are £18.00+vat each and their not available either :/

the exhaust valves are available but their £40+vat...

http://www.cmsnl.com/honda-vfr400rh-198 ... partslist/" onclick="window.open(this.href);return false;

If you look there you'll find all the microfiche, with part numbers that you can search on david silver spares and lings to see whats available / what isnt.

2nd engine probably a better idea.. or just break it for spares.. if it has a good exhaust / collectorbox there worth some cash :)

[sandfish]

it a thread in type but i have both in the kit I'll recheck compression tom., and do valve clearance, re test then strip and see whats what, I'm trying not to go over the top on the budget, the rest of the rebuild will cost me next to fa as I will do the respray and make my own collector box, I have a slight reluctance to 'have it put down' but then again I have always wanted to build a 'special'

[Neosophist]

it a thread in type but i have both in the kit I'll recheck compression tom., and do valve clearance, re test then strip and see whats what, I'm trying not to go over the top on the budget, the rest of the rebuild will cost me next to fa as I will do the respray and make my own collector box, I have a slight reluctance to 'have it put down' but then again I have always wanted to build a 'special'

Then put an NC30 engine in the bike

An NC30/35 frame would be a much better candidate for a special.. more bits available, better frame, better forks, better brakes, more options :D

But at the end of the day it depends on if you want to ever get any money back or just like the fun :)

If I had the time & space i'd like to build an NC35 with an NC24 motor & 16" front wheel (early fireblade one) 4xfcr's & urban tiger scheme but in the RVF colors.

That'd rock. :)

If you are gonna be ripping it to pieces, if you get stuck at all don't hesitate to ask any questions / queries.

[sandfish]

what a week ! at last had time to get the tools to it, OMG all the valves needed adjusting this gave a slight improvement in compression, so head off and I found the two centre exhaust valve guide badly (2 and 4 ) worn the two valves cracked around the edge and a nice 'dimple' in the valve seat, far to deep to grind out. looks like I need to find a new top end !!!! Neo, why would you go for the 24 in a 30 frame ??

[fastdruid]

At a guess the 180 rather than 360 motor.

Druid