chappo

Hi , yes I’ve read the article. Thank you.

Thanks Bullylover, I’ll try that, but please guys keep the advice coming, someone must have solved this niggle somewhere surely.

I’m the proud owner of a Fantic 240 which is displaying a detonation sound. I’ve already noted the post in December 2019, which covered this topic but did not provide a cure. Although the member did say what he’d done had reduced it. Just wondering if anyone has found a cure for it since that last post. To set the scene, the engine has had a full rebuild, new piston, rebore, cylinder coated, all bearings and seals. It sounds wonderful apart from the occasional detonation sound. The carb is a new Dellorto, jetted as per the manual. It has a brand new front pipe and WES rear silencer. I’ve just put a new NGK plug in her and some super unleaded fuel at 70:1 mix with fully synthetic Shell 2stroke oil. I’ve got an NGK iridium plug on order. Starts almost first time every time so the timing must be right. Any thoughts would be appreciated.

Sent you a message, check your inbox ??

Welcome. Can I recommend Red Rose trials club based in East Lancs. They put on excellent twinshock events. They're on Facebook and obviously have a website.

Thanks to everyone who replied, fantastic website. At least I know it’s a SM Hi Boy. Lorenzo do you have any text to go with that photo/ image you sent me, looks like there’s a write up with it. Thanks. Its not for sale, going to be a future project, but what value would you put on one of these frames ??

Ok guys I’ve read all the old stuff on these frames before posting this,just so you know. But I’ve just bought a load of Bultó bits and one was this frame. In the old stuff it says that this frame is documented In Don Morley's Classic Spanish Trials Bikes book on page 40, Is there anyone out there with this book that could forward the image to me. It’s just that what ive read all Miller frames had a number prefixed by SM. Ive enclosed an image of my frame number, but not prefixed by SM. Basically is it a Miller frame, or a Whitlock frame or something else. Many thanks guys.

I’ve had a DC bike rack for five years now on a Renault 4x4, it’s taken modern bikes and a variety of twinshocks, never had an issue. No speed restrictions, or reversing issues. Lot more stable than you’ll probably think. DO check the nose weight of the tow bar you’ll be using.

Ok guys, being a bit cheeky here. My Amal has had its day I feel so looking for an alternative carb. OKO seem to get a good review and I’m aware of all the copies and the preferred purchase site. What do people use 26 or 28 mm and most importantly what are the best jet sizes? It doesn’t say on the Ebay site what jets are in as standard when you purchase a carb.

Bisby, can I be cheeky and ask what size OKO you chose, 26 or 28 and what jets your using. I was going to get one from scooter assassins but not sure if you get jets with the standard carb. My Gripper original Amal is worn out. Many thanks. Dave.

Ive had regular contact with Steve over the past 3 months whilst rebuilding my 350 Gripper via his email. He has always replied, sometimes there was a couple of days before the reply came. This guy has a superb knowledge of Ossa's and has been instrumental in the rebuilding of my bike. marlimar.ossa@gmail.com PS He also supplies excellent parts. I bought a big end kit and other bits, excellent quality.

Absolutely superb RMS. Thank you.

Can I ask RMS, where is the above info from, do you have a Gripper manual?

Thanks RMS, the above is excellent info for the rest. Just for clarity, these are the same spec for a 350 Gripper ? I notice you give two seal thicknesses 6mm and 8mm , are they different each side?

Guys, what main bearings are you using in your OSSA Grippers. The ones i took out are SKF ( OTHER BRANDS ARE AVAILABLE ), 6205 2 RSH . I only ask as i read this in an OSSA manual, bearing in mind its not a manual for the 350 Gripper................. NOTE: The left main bearing (OSSA Part No. 991-141) is slightly different than the right main bearing (OSSA Part No. 991-140). They are essentially the same bearings, but the internal clearance between the balls and races of the left bearing are greater than in the right. This difference is noted by the letters "C3" either stamped or printed on some part of the left bearing (Fig. 76 and 77). It is not recommended that a bearing without this "C3" marking be installed as a left main bearing. I know these bearings would have had a rubber seal in them which was removed hence RS rating. Also noted is the absence of seal carriers they are just tapped into the crankcase, seems odd !!! Thanks.

Could anyone tell me what fits into the recess on the front exhaust pipe, looks to be some form of o ring. Where can I source one please and what material would it need to be in that hot location. Many thanks all ??

Barnsey, do it yourself, well the prep work. Get a Dremmel ( other makes are available ) with a 1mm thick cutting disc, cut a section of each silencer out, take out whatever you find in there. My rear silencer was choked up with oily residue, the perforated baffle tubes were solid. The front pipe silencer had nothing in it at all, had obviously blown it all out. Buy some exhaust matting, or you can buy it loose, i just find the matting is easier to apply. When i get them back ill post a picture then you know where to cut. The matting was about a tenner for a lot. The welding is being done by a family member, so a few beers in cost. Not a costly process considering. I did my Sherpa and it did make a difference, now runs smooth with a lovely exhaust tone, not sure how the 348 will pan out. Hope this helps.

Feetupfun , yes I can easily get the plug on and off when the exhaust is in place. Should be back from the welders this week, had the boxes repacked with matting, I’ll put it on and send you an image or two. ??

Just rebuilding one, that’s mine ??

That is a really nice job Fantic303. May have located an original one in Spain, investigations are still ongoing ?

The Gripper I recently purchased has a length of hydraulic flexible hose connecting the cylindrical exhaust chamber by the swingarm to an original back box. What should it be , I can’t find any images anywhere of what original would be. A pic or two would help guys.

Just putting my 348 back together, I’m a little confused as I’ve seen an exploded diagram of the gearbox and it shows an o ring on one of the rear uppermost casing bolts. I’ve since been told that all the casing bolts need an o ring. None on when I split it.What is the purpose, presumably to prevent oil loss, but where do they go, can find any indentations in any of the bolts to slide it onto. Is it one, or one at each end, one in the middle. Help guys ??? Also struggling to find a torque value for the final drive sprocket nut. Thanks everyone in advance of the usual abundance of practical advice and experience.

That’s the deeper rich yellow I’m after, it’s the colour of the bike now, 1018 is far too pale. Thanks Woody. ??

I have researched the site before i get told off. I noted forum posts from 2008 from WOODY, ( TRIED TO SEND YOU A MESSAGE BUT IT WOULDN'T ACCEPT IT !! ) The original colour of yellow is RAL 1018, Zinc yellow, although some people say its to pale. I bought a can of 1018, primed it in grey and sprayed it, they were right a far paler shade than the one its wearing now. On speaking to other people i've been told that it needs a white primer. WOODY in 2008 you recommended, RAL 1021 , can you remember was it a white or grey primer. you used. Has anyone sprayed one up recently with a different opinion or RAL code. Thanks.