Re: Bike engine rebuild experience

Topic Approved

I know a lot of people who have gotten their engine rebuilt and are happy with the build quality.

It depends entirely on what you want. If you want to keep the bike, then work on the engine, if you are planning to upgrade then sell off the bike and buy a new bike.

Re: Bike engine rebuild experience

Some people and specially mechanic claim that engine will be close to new engine after majour engine overhaul.

But I dought on this because most of the mechanics I have seen do not practice right way of engine work.
They do not use right tools and do not work as mentioned on service manual.
Any service center of yamaha here in nepal use torque wrench which I believe is a must for critical engine work.

I was really disappointed by the way mechanic worked ,When I had valve polising and head decarbonization of my fz .

Here are the points I think will help you to get the job done properly:
1: Wash bike propely specially engine area and blow away dust form parts near engine before letting the mechanic open the engine.
2: Scratch off previous gasket form the mating surface of engine case before sending to lathe work.
Mecahincs usually do this after getting parts from lathe.
3:Arrange some clean rags .Mechanic use dirty rags which I find really irritating.
3:Get some packing plastic bags and small plastic box to keep nut bolts and engine internals.

4: Go through service manual if u can get and insist on using specified lubricant on the engine parts before assembling.

5:If u can get a torque wrench it will be best to use it.
I have got beam style torque wrench but it has high range and is lage in size nut still I use it when possible.
Usualy head nut bolts, timing chain sprocket bolts etc.

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Re: Bike engine rebuild experience

From your description it seems that the engine is in decent shape other than the oil consumption (you have not mentioned any drop in power or fuel efficiency). Before taking a call on whether to overhaul the engine or not it would be prudent to do the following:

1. Do a compression test. If the values are within the service limit, you may not need to overhaul the engine. However, this is subject to point 2.

2. The exact cause of why it consuming oil can only be determined by opening the engine. If there is carbon buildup due to oil consumption on the piston crown and/or head, it will give a inflated compression reading. Therefore, it may need to be decarbed and another compression test may be required to get an accurate reading.

3. If the compression reading is within limits and once you know the cause of the oil consumption, it may very well be that you simply change the required part to stop the oil consumption. For example, if the oil rings are the culprit, just replacing the oil rings may solve your problem. However, if you do change the oil ring, I would advise you to also put in new piston rings.

Re: Bike engine rebuild experience


Hi there Deep

First of all - this is going to be a very loooong post . I would like to apologise for it.

NOW to start the real discussion.

I have done a complete engine rebuild on my bajaj XCD long time back. A word of caution about bajaj bike rebuild is the non-availability of parts. The discover 135 has been discontinued and availability of spare parts will be an issue. So u have to take a decision whether to go through the trouble of sourcing spare parts and spending on a rebuild or else u have an option of selling the bike.

Now coming to the actual rebuild.

The engine rebuild can be a partial rebuild involving the engine head or a complete rebuild involving the block piston assembly.

Partial rebuild involves

1.) removing the engine head ONLY. (take extra care and DO NOT touch or disturb the block-piston assembly. If it is disturbed, it will cause white smoke from exhaust and u have to go for another rebuild)

2.) scrap gasket remains from the head.

3.) complete decarbonization of engine head.

4.) change to new valves. (the valves have to be polished along with the engine head for precise fit. This requires lathe work)

5.) change valve seals and gasket.

6.) scrape of carbon deposits from the top of the piston without disturbing the block piston assembly.

The whole process should cost you between 2K to 3k. (inclusive of labor, spare parts etc)


NOW coming to a complete rebuild

1.) You have to follow the above process + follow below procedure

2.) Buy a block - piston assembly. (may cost you around 3 K)

3.) you will have to buy the piston rings and gaskets separtely. (2 gaskets are required here, 1st between the engine head and engine block, 2nd between the engine block and the engine)

4.) Change the bushes around the crankshaft.

5.) buy clutch plate, pressure plate set. replace that

6.) If u havent changed the chain sprocket in the last 50K kms. Replace chain and front - back sprocket set.

If you go for complete rebuild, u will also have to change engine oil and oil filter. Please note that this is a major overhaul. Your bike will be as good as new. It will be as if you are riding a brand new bike. You will have to follow the engine run-in process again after the complete rebuild. Also 1st servicing at 500kms, 2nd at 2000 kms. etc. Cost might go upward of 10 - 13 K

If you have any queries, I will happily help you out.

Thanks for the patience to read through the looooong post

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Hi Abhimanyu.

Do u know of any centers who do compression tests? what are the charges? I would like to do compression tests on my bikes. thanks

Re: Bike engine rebuild experience

Thanks for approval ...I have a pulsar 200ns with me only for the highway when I am not going to the office

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Re: Bike engine rebuild experience

The bike has completed 50K kms. At this point, just changing oil and piston rings will not stop oil consumption as the new rings will not get properly "seated" on the old block piston and may require another rebuild to put in a new block piston.

Re: Bike engine rebuild experience

Thanks honda-Abhi for your valuable advice ..I have done compression test on my bike almost 6 months back it is little less than normal and they have quoted Rs5500 for the engine work and i do not know what they want to change .I will visit the service center Dada motors in ludhiana ,punjab to get what they change in my bike and what would the cost

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Re: Bike engine rebuild experience

Hi there Deep,

I have mentioned names of parts. Please ask the service center what will be covered from the list I mentioned. If it is a bajaj service center, then for 5.5K it will be a partial rebuild. which seems a bit costly. A good 2 wheeler garage will do it in 3K. And partial rebuild will not solve the oil consumption issue.

If your bike is consuming oil, that means you have to change the block-piston assembly and the piston-oil rings. I had made this mistake and had to go for another rebuild in 2 months and had to pay double labor charges.

Re: Bike engine rebuild experience


If I have to do the full engine work which would cost 10000-12000rupees than I will thinking to purchase a new bike.

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Re: Bike engine rebuild experience

full engine work will cost 6-7K. It will involve the partial rebuild process as I mentioned before + new block piston assembly+new piston /oil rings.

If you also change clutch plate, sprocket wheel set, chain etc., then the cost will go above 10K.

My suggestion is to get a quotation from a couple of garages and then take a decision whether to rebuild current bike or buy a new one.

Re: Bike engine rebuild experience

Hi friends, yesterday, I got engine overhaul done along with new piston+rings, new valve set, head decarb and polish, new timing chain and tensioner, I feel like engine is new, however, it started to produce sever vibrations, my bike never vibrated so much, now it vibrates like i have installed Enfield engine on pulsar chassis, i paid a hell a lot of labour but now i am unhappy, please suggest me what needs be done

Re: Bike engine rebuild experience

I think you are getting noise from the tapped of your engine, actually when a new block piston is installed,they tapped is supposed to be loose,after 1000 km when you do service of your bike,then the mechanic will tighten the tapped and the noise will be gone. For first 1000 km ride your bike below 50km/hr. This will give life to your bike and you will feel like new one.

Re: Bike engine rebuild experience

If done properly with the right components replaced by the right way, it should do as good as a new engine.

One thing is we should preferably change a component rather than changing a piece for better stability.